From 20c47222e7ba9944a6c32a53333dcaa8e7b3c548 Mon Sep 17 00:00:00 2001 From: gemmaro Date: Thu, 30 Nov 2023 19:18:14 +0900 Subject: [PATCH] [ update ] Japanese translation [ update ] PO files --- text-ja/chapter6.md | 53 +++- translation/po/all.pot | 524 +++++++++++++++++++----------------- translation/po/ja.po | 587 +++++++++++++++++++++++------------------ 3 files changed, 659 insertions(+), 505 deletions(-) diff --git a/text-ja/chapter6.md b/text-ja/chapter6.md index 40920289..24849b7c 100644 --- a/text-ja/chapter6.md +++ b/text-ja/chapter6.md @@ -51,11 +51,49 @@ instance Show Boolean where show false = "false" ``` -このコードは `showBool​​ean`という名前の型クラスのインスタンスを宣言します。 -PureScriptでは、生成されたJavaScriptの可読性を良くするために、型クラスインスタンスに名前を付けられます。 -このとき、`Boolean`型は *`Show`型クラスに属している* といいます。 - -PSCiで、いろいろな型の値を`Show`型クラスを使って表示してみましょう。 +このコードは型クラスのインスタンスを宣言します。 +`Boolean`型は *`Show`型クラスに属すもの* としています。 + +> ピンとこなければ、生成されるJSのコードは以下のようになります。 +> +> ```javascript +> var showBoolean = { +> show: function (v) { +> if (v) { +> return "true"; +> }; +> if (!v) { +> return "false"; +> }; +> throw new Error("Failed pattern match at ..."); +> } +> }; +> ``` +> +> 生成される名前が気に入らなければ、型クラスインスタンスに名前を与えられます。 +> 例えば次のようにします。 +> +> ```haskell +> instance myShowBoolean :: Show Boolean where +> show true = "true" +> show false = "false" +> ``` +> +> ```javascript +> var myShowBoolean = { +> show: function (v) { +> if (v) { +> return "true"; +> }; +> if (!v) { +> return "false"; +> }; +> throw new Error("Failed pattern match at ..."); +> } +> }; +> ``` + +PSCiでいろいろな型の値を`Show`型クラスを使って表示してみましょう。 ```text > import Prelude @@ -191,8 +229,9 @@ true この関数は2つの値を比較するのに使えるもので、その値の型は順序付けに対応したものです。 比較演算子`<`、`>`と厳密な大小比較ではない`<=`、`>=`は`compare`を用いて定義されます。 -*補足*：以下の例ではクラスシグネチャに`<=`が含まれています。 -この文脈での`<=`の使われ方はEqがOrdの上位クラスであり、比較演算子としての`<=`の用途を表す意図はありません。 +*補足*： +以下の例ではクラスシグネチャに`<=`が含まれています。 +この文脈での`<=`の使われ方は、`Eq`が`Ord`の上位クラスであり、比較演算子としての`<=`の用途を表す意図はありません。 後述の[上位クラス](#上位クラス)の節を参照してください。 ```haskell diff --git a/translation/po/all.pot b/translation/po/all.pot index 9da96c52..b838f7e6 100644 --- a/translation/po/all.pot +++ b/translation/po/all.pot @@ -7,7 +7,7 @@ msgid "" msgstr "" "Project-Id-Version: PACKAGE VERSION\n" -"POT-Creation-Date: 2023-11-12 11:27+0900\n" +"POT-Creation-Date: 2023-11-30 19:18+0900\n" "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" "Last-Translator: FULL NAME \n" "Language-Team: LANGUAGE \n" @@ -1624,8 +1624,8 @@ msgstr "" #: ../text/chapter4.md:101 ../text/chapter4.md:230 ../text/chapter4.md:394 #: ../text/chapter4.md:467 ../text/chapter4.md:526 ../text/chapter5.md:72 #: ../text/chapter5.md:183 ../text/chapter5.md:373 ../text/chapter5.md:531 -#: ../text/chapter5.md:625 ../text/chapter6.md:130 ../text/chapter6.md:321 -#: ../text/chapter6.md:411 ../text/chapter6.md:608 ../text/chapter6.md:742 +#: ../text/chapter5.md:625 ../text/chapter6.md:168 ../text/chapter6.md:359 +#: ../text/chapter6.md:449 ../text/chapter6.md:646 ../text/chapter6.md:780 #: ../text/chapter7.md:381 ../text/chapter7.md:540 ../text/chapter7.md:642 #: ../text/chapter8.md:308 ../text/chapter8.md:667 ../text/chapter8.md:974 #: ../text/chapter9.md:87 ../text/chapter9.md:134 ../text/chapter9.md:201 @@ -3480,7 +3480,7 @@ msgstr "" #: ../text/chapter10.md:1083 ../text/chapter11.md:963 ../text/chapter12.md:594 #: ../text/chapter13.md:401 ../text/chapter14.md:720 ../text/chapter2.md:128 #: ../text/chapter3.md:782 ../text/chapter4.md:531 ../text/chapter5.md:641 -#: ../text/chapter6.md:757 ../text/chapter7.md:691 ../text/chapter8.md:1001 +#: ../text/chapter6.md:795 ../text/chapter7.md:691 ../text/chapter8.md:1001 #: ../text/chapter9.md:238 #, markdown-text, no-wrap msgid "Conclusion" @@ -17332,22 +17332,64 @@ msgstr "" #: ../text/chapter6.md:51 #, markdown-text msgid "" -"This code declares a type class instance called `showBoolean` – in " -"PureScript, type class instances can be named to aid the readability of the " -"generated JavaScript. We say that the `Boolean` type _belongs to the `Show` " -"type class_." +"This code declares a type class instance; we say that the `Boolean` type " +"_belongs to the `Show` type class_." msgstr "" #. type: Plain text -#: ../text/chapter6.md:53 +#: ../text/chapter6.md:89 +#, markdown-text, no-wrap +msgid "" +"> If you're wondering, the generated JS code looks like this:\n" +">\n" +"> ```javascript\n" +"> var showBoolean = {\n" +"> show: function (v) {\n" +"> if (v) {\n" +"> return \"true\";\n" +"> };\n" +"> if (!v) {\n" +"> return \"false\";\n" +"> };\n" +"> throw new Error(\"Failed pattern match at ...\");\n" +"> }\n" +"> };\n" +"> ```\n" +">\n" +"> If you're unhappy with the generated name, you can give names to type " +"class instances. For example:\n" +">\n" +"> ```haskell\n" +"> instance myShowBoolean :: Show Boolean where\n" +"> show true = \"true\"\n" +"> show false = \"false\"\n" +"> ```\n" +">\n" +"> ```javascript\n" +"> var myShowBoolean = {\n" +"> show: function (v) {\n" +"> if (v) {\n" +"> return \"true\";\n" +"> };\n" +"> if (!v) {\n" +"> return \"false\";\n" +"> };\n" +"> throw new Error(\"Failed pattern match at ...\");\n" +"> }\n" +"> };\n" +"> ```\n" +msgstr "" + +#. type: Plain text +#: ../text/chapter6.md:91 #, markdown-text msgid "" -"We can try out the `Show` type class in PSCi, by showing a few values with " +"We can try out the `Show` type class in PSCi by showing a few values with " "different types:" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:54 +#: ../text/chapter6.md:92 #, no-wrap msgid "" "> import Prelude\n" @@ -17363,7 +17405,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:68 +#: ../text/chapter6.md:106 #, markdown-text msgid "" "These examples demonstrate how to `show` values of various primitive types, " @@ -17371,7 +17413,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:69 +#: ../text/chapter6.md:107 #, no-wrap msgid "" "> import Data.Tuple\n" @@ -17386,7 +17428,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:82 +#: ../text/chapter6.md:120 #, markdown-text msgid "" "The output of `show` should be a string that you can paste back into the " @@ -17397,7 +17439,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:83 +#: ../text/chapter6.md:121 #, no-wrap msgid "" "> import Effect.Console\n" @@ -17412,7 +17454,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:96 +#: ../text/chapter6.md:134 #, markdown-text msgid "" "If we try to show a value of type `Data.Either`, we get an interesting error " @@ -17420,7 +17462,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:97 +#: ../text/chapter6.md:135 #, no-wrap msgid "" "> import Data.Either\n" @@ -17435,7 +17477,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:109 +#: ../text/chapter6.md:147 #, markdown-text msgid "" "The problem here is not that there is no `Show` instance for the type we " @@ -17444,7 +17486,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:111 +#: ../text/chapter6.md:149 #, markdown-text msgid "" "We can annotate the expression with a type using the `::` operator, so that " @@ -17452,7 +17494,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:112 +#: ../text/chapter6.md:150 #, no-wrap msgid "" "> show (Left 10 :: Either Int String)\n" @@ -17460,7 +17502,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:118 +#: ../text/chapter6.md:156 #, markdown-text, no-wrap msgid "" "Some types do not have a `Show` instance defined at all. One example of this " @@ -17469,7 +17511,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:119 +#: ../text/chapter6.md:157 #, no-wrap msgid "" "> import Prelude\n" @@ -17481,7 +17523,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:129 +#: ../text/chapter6.md:167 #, markdown-text msgid "" "Type class instances can be defined in one of two places: in the same module " @@ -17496,7 +17538,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:133 +#: ../text/chapter6.md:171 #, markdown-text msgid "" "(Easy) Define a `Show` instance for `Point`. Match the same output as the " @@ -17507,7 +17549,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:137 +#: ../text/chapter6.md:175 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -17517,13 +17559,13 @@ msgid "" msgstr "" #. type: Title ## -#: ../text/chapter6.md:138 +#: ../text/chapter6.md:176 #, markdown-text, no-wrap msgid "Common Type Classes" msgstr "" #. type: Plain text -#: ../text/chapter6.md:141 +#: ../text/chapter6.md:179 #, markdown-text msgid "" "In this section, we'll look at some standard type classes defined in the " @@ -17533,13 +17575,13 @@ msgid "" msgstr "" #. type: Title ### -#: ../text/chapter6.md:142 +#: ../text/chapter6.md:180 #, markdown-text, no-wrap msgid "Eq" msgstr "" #. type: Plain text -#: ../text/chapter6.md:145 +#: ../text/chapter6.md:183 #, markdown-text msgid "" "The `Eq` type class defines the `eq` function, which tests two values for " @@ -17547,7 +17589,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:146 +#: ../text/chapter6.md:184 #, no-wrap msgid "" "class Eq a where\n" @@ -17555,7 +17597,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:152 +#: ../text/chapter6.md:190 #, markdown-text msgid "" "In either case, the two arguments must have the same type: it does not make " @@ -17563,13 +17605,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:154 +#: ../text/chapter6.md:192 #, markdown-text msgid "Try out the `Eq` type class in PSCi:" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:155 +#: ../text/chapter6.md:193 #, no-wrap msgid "" "> 1 == 2\n" @@ -17580,13 +17622,13 @@ msgid "" msgstr "" #. type: Title ### -#: ../text/chapter6.md:163 +#: ../text/chapter6.md:201 #, markdown-text, no-wrap msgid "Ord" msgstr "" #. type: Plain text -#: ../text/chapter6.md:166 +#: ../text/chapter6.md:204 #, markdown-text, no-wrap msgid "" "The `Ord` type class defines the `compare` function, which can be used to " @@ -17596,17 +17638,17 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:168 +#: ../text/chapter6.md:206 #, markdown-text, no-wrap msgid "" "_Note_: In the example below, the class signature contains `<=`. This usage " -"of `<=` in this context indicates that Eq is a subclass of Ord and is not " -"intended to represent the use of `<=` as a comparison operator. See the " +"of `<=` in this context indicates that `Eq` is a superclass of `Ord` and is " +"not intended to represent the use of `<=` as a comparison operator. See the " "section [Superclasses](#superclasses) below.\n" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:169 +#: ../text/chapter6.md:207 #, no-wrap msgid "" "data Ordering = LT | EQ | GT\n" @@ -17616,7 +17658,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:177 +#: ../text/chapter6.md:215 #, markdown-text msgid "" "The `compare` function compares two values and returns an `Ordering`, which " @@ -17624,31 +17666,31 @@ msgid "" msgstr "" #. type: Bullet: '- ' -#: ../text/chapter6.md:181 +#: ../text/chapter6.md:219 #, markdown-text msgid "`LT` – if the first argument is less than the second." msgstr "" #. type: Bullet: '- ' -#: ../text/chapter6.md:181 +#: ../text/chapter6.md:219 #, markdown-text msgid "`EQ` – if the first argument is equal to the second." msgstr "" #. type: Bullet: '- ' -#: ../text/chapter6.md:181 +#: ../text/chapter6.md:219 #, markdown-text msgid "`GT` – if the first argument is greater than the second." msgstr "" #. type: Plain text -#: ../text/chapter6.md:183 +#: ../text/chapter6.md:221 #, markdown-text msgid "Again, we can try out the `compare` function in PSCi:" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:184 +#: ../text/chapter6.md:222 #, no-wrap msgid "" "> compare 1 2\n" @@ -17659,13 +17701,13 @@ msgid "" msgstr "" #. type: Title ### -#: ../text/chapter6.md:192 +#: ../text/chapter6.md:230 #, markdown-text, no-wrap msgid "Field" msgstr "" #. type: Plain text -#: ../text/chapter6.md:195 +#: ../text/chapter6.md:233 #, markdown-text msgid "" "The `Field` type class identifies those types which support numeric " @@ -17675,7 +17717,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:197 +#: ../text/chapter6.md:235 #, markdown-text, no-wrap msgid "" "> _Note_: Just like the `Eq` and `Ord` type classes, the `Field` type class " @@ -17685,13 +17727,13 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:198 +#: ../text/chapter6.md:236 #, no-wrap msgid "class EuclideanRing a <= Field a\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:203 +#: ../text/chapter6.md:241 #, markdown-text msgid "" "The `Field` type class is composed from several more general " @@ -17704,7 +17746,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:205 +#: ../text/chapter6.md:243 #, markdown-text msgid "" "Superclasses will be explained later in this chapter, but the full [numeric " @@ -17716,13 +17758,13 @@ msgid "" msgstr "" #. type: Title ### -#: ../text/chapter6.md:206 +#: ../text/chapter6.md:244 #, markdown-text, no-wrap msgid "Semigroups and Monoids" msgstr "" #. type: Plain text -#: ../text/chapter6.md:209 +#: ../text/chapter6.md:247 #, markdown-text msgid "" "The `Semigroup` type class identifies those types which support an `append` " @@ -17730,7 +17772,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:210 +#: ../text/chapter6.md:248 #, no-wrap msgid "" "class Semigroup a where\n" @@ -17738,7 +17780,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:216 +#: ../text/chapter6.md:254 #, markdown-text msgid "" "Strings form a semigroup under regular string concatenation, and so do " @@ -17746,7 +17788,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:218 +#: ../text/chapter6.md:256 #, markdown-text, no-wrap msgid "" "The `<>` concatenation operator, which we have already seen, is provided as " @@ -17754,7 +17796,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:220 +#: ../text/chapter6.md:258 #, markdown-text msgid "" "The `Monoid` type class (provided by the `prelude` package) extends the " @@ -17762,7 +17804,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:221 +#: ../text/chapter6.md:259 #, no-wrap msgid "" "class Semigroup m <= Monoid m where\n" @@ -17770,13 +17812,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:227 +#: ../text/chapter6.md:265 #, markdown-text msgid "Again, strings and arrays are simple examples of monoids." msgstr "" #. type: Plain text -#: ../text/chapter6.md:229 +#: ../text/chapter6.md:267 #, markdown-text msgid "" "A `Monoid` type class instance for a type describes how to _accumulate_ a " @@ -17786,7 +17828,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:230 +#: ../text/chapter6.md:268 #, no-wrap msgid "" "> import Prelude\n" @@ -17801,7 +17843,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:243 +#: ../text/chapter6.md:281 #, markdown-text msgid "" "The `prelude` package provides many examples of monoids and semigroups, " @@ -17809,13 +17851,13 @@ msgid "" msgstr "" #. type: Title ### -#: ../text/chapter6.md:244 +#: ../text/chapter6.md:282 #, markdown-text, no-wrap msgid "Foldable" msgstr "" #. type: Plain text -#: ../text/chapter6.md:247 +#: ../text/chapter6.md:285 #, markdown-text msgid "" "If the `Monoid` type class identifies those types which act as the result of " @@ -17824,7 +17866,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:249 +#: ../text/chapter6.md:287 #, markdown-text msgid "" "The `Foldable` type class is provided in the `foldable-traversable` package, " @@ -17833,7 +17875,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:251 +#: ../text/chapter6.md:289 #, markdown-text msgid "" "The type signatures for the functions belonging to the `Foldable` class are " @@ -17841,7 +17883,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:252 +#: ../text/chapter6.md:290 #, no-wrap msgid "" "class Foldable f where\n" @@ -17851,7 +17893,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:260 +#: ../text/chapter6.md:298 #, markdown-text msgid "" "It is instructive to specialize to the case where `f` is the array type " @@ -17861,7 +17903,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:262 +#: ../text/chapter6.md:300 #, markdown-text, no-wrap msgid "" "What about `foldMap`? Well, that becomes `forall a m. Monoid m => (a -> m) " @@ -17873,13 +17915,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:264 +#: ../text/chapter6.md:302 #, markdown-text msgid "Let's try out `foldMap` in PSCi:" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:265 +#: ../text/chapter6.md:303 #, no-wrap msgid "" "> import Data.Foldable\n" @@ -17889,7 +17931,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:273 +#: ../text/chapter6.md:311 #, markdown-text msgid "" "Here, we choose the monoid for strings, which concatenates strings together, " @@ -17899,7 +17941,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:275 +#: ../text/chapter6.md:313 #, markdown-text msgid "" "But arrays are not the only types that are foldable. `foldable-traversable` " @@ -17909,13 +17951,13 @@ msgid "" msgstr "" #. type: Title ### -#: ../text/chapter6.md:276 +#: ../text/chapter6.md:314 #, markdown-text, no-wrap msgid "Functor and Type Class Laws" msgstr "" #. type: Plain text -#: ../text/chapter6.md:279 +#: ../text/chapter6.md:317 #, markdown-text msgid "" "The Prelude also defines a collection of type classes that enable a " @@ -17926,7 +17968,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:280 +#: ../text/chapter6.md:318 #, no-wrap msgid "" "class Functor f where\n" @@ -17934,7 +17976,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:286 +#: ../text/chapter6.md:324 #, markdown-text, no-wrap msgid "" "The `map` function (and its alias `<$>`) allows a function to be \"lifted\" " @@ -17944,7 +17986,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:287 +#: ../text/chapter6.md:325 #, no-wrap msgid "" "> import Prelude\n" @@ -17960,7 +18002,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:301 +#: ../text/chapter6.md:339 #, markdown-text msgid "" "How can we understand the meaning of the `map` function, when it acts on " @@ -17968,7 +18010,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:303 +#: ../text/chapter6.md:341 #, markdown-text msgid "" "Well, we can build an intuition that the `map` function applies the function " @@ -17978,7 +18020,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:305 +#: ../text/chapter6.md:343 #, markdown-text msgid "" "Type class instances for `Functor` are expected to adhere to a set of " @@ -17986,19 +18028,19 @@ msgid "" msgstr "" #. type: Bullet: '- ' -#: ../text/chapter6.md:308 +#: ../text/chapter6.md:346 #, markdown-text msgid "`map identity xs = xs`" msgstr "" #. type: Bullet: '- ' -#: ../text/chapter6.md:308 +#: ../text/chapter6.md:346 #, markdown-text msgid "`map g (map f xs) = map (g <<< f) xs`" msgstr "" #. type: Plain text -#: ../text/chapter6.md:310 +#: ../text/chapter6.md:348 #, markdown-text msgid "" "The first law is the _identity law_. It states that lifting the identity " @@ -18008,7 +18050,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:312 +#: ../text/chapter6.md:350 #, markdown-text msgid "" "The second law is the _composition law_. It states that mapping one function " @@ -18017,7 +18059,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:314 +#: ../text/chapter6.md:352 #, markdown-text msgid "" "Whatever \"lifting\" means in the general sense, it should be true that any " @@ -18026,7 +18068,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:316 +#: ../text/chapter6.md:354 #, markdown-text msgid "" "Many standard type classes come with their own set of similar laws. The laws " @@ -18037,13 +18079,13 @@ msgid "" msgstr "" #. type: Title ### -#: ../text/chapter6.md:317 +#: ../text/chapter6.md:355 #, markdown-text, no-wrap msgid "Deriving Instances" msgstr "" #. type: Plain text -#: ../text/chapter6.md:320 +#: ../text/chapter6.md:358 #, markdown-text msgid "" "Rather than writing instances manually, you can let the compiler do most of " @@ -18053,19 +18095,19 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:324 +#: ../text/chapter6.md:362 #, markdown-text msgid "The following newtype represents a complex number:" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:325 +#: ../text/chapter6.md:363 #, no-wrap msgid "{{#include ../exercises/chapter6/test/no-peeking/Solutions.purs:Complex}}\n" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:330 +#: ../text/chapter6.md:368 #, markdown-text msgid "" "(Easy) Define a `Show` instance for `Complex`. Match the output format " @@ -18073,7 +18115,7 @@ msgid "" msgstr "" #. type: Bullet: '2. ' -#: ../text/chapter6.md:332 +#: ../text/chapter6.md:370 #, markdown-text msgid "" "(Easy) Derive an `Eq` instance for `Complex`. _Note_: You may instead write " @@ -18081,7 +18123,7 @@ msgid "" msgstr "" #. type: Bullet: '3. ' -#: ../text/chapter6.md:334 +#: ../text/chapter6.md:372 #, markdown-text msgid "" "(Medium) Define a `Semiring` instance for `Complex`. _Note_: You can use " @@ -18093,7 +18135,7 @@ msgid "" msgstr "" #. type: Bullet: '4. ' -#: ../text/chapter6.md:336 +#: ../text/chapter6.md:374 #, markdown-text msgid "" "(Easy) Derive (via `newtype`) a `Ring` instance for `Complex`. _Note_: You " @@ -18101,13 +18143,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:338 +#: ../text/chapter6.md:376 #, markdown-text, no-wrap msgid " Here's the `Shape` ADT from the previous chapter:\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:342 +#: ../text/chapter6.md:380 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -18117,7 +18159,7 @@ msgid "" msgstr "" #. type: Bullet: '5. ' -#: ../text/chapter6.md:344 +#: ../text/chapter6.md:382 #, markdown-text msgid "" "(Medium) Derive (via `Generic`) a `Show` instance for `Shape`. How does the " @@ -18130,13 +18172,13 @@ msgid "" msgstr "" #. type: Title ## -#: ../text/chapter6.md:345 +#: ../text/chapter6.md:383 #, markdown-text, no-wrap msgid "Type Class Constraints" msgstr "" #. type: Plain text -#: ../text/chapter6.md:348 +#: ../text/chapter6.md:386 #, markdown-text msgid "" "Types of functions can be constrained by using type classes. Here is an " @@ -18145,7 +18187,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:349 +#: ../text/chapter6.md:387 #, no-wrap msgid "" "threeAreEqual :: forall a. Eq a => a -> a -> a -> Boolean\n" @@ -18153,7 +18195,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:355 +#: ../text/chapter6.md:393 #, markdown-text, no-wrap msgid "" "The type declaration looks like an ordinary polymorphic type defined using " @@ -18162,7 +18204,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:357 +#: ../text/chapter6.md:395 #, markdown-text msgid "" "This type says that we can call `threeAreEqual` with any choice of type `a`, " @@ -18171,7 +18213,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:359 +#: ../text/chapter6.md:397 #, markdown-text msgid "" "Constrained types can contain several type class instances, and the types of " @@ -18180,7 +18222,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:360 +#: ../text/chapter6.md:398 #, no-wrap msgid "" "showCompare :: forall a. Ord a => Show a => a -> a -> String\n" @@ -18193,7 +18235,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:372 +#: ../text/chapter6.md:410 #, markdown-text, no-wrap msgid "" "Note that multiple constraints can be specified by using the `=>` symbol " @@ -18202,7 +18244,7 @@ msgid "" msgstr "" #. type: Bullet: '- ' -#: ../text/chapter6.md:375 +#: ../text/chapter6.md:413 #, markdown-text msgid "" "`a -> b` denotes the type of functions from _type_ `a` to _type_ `b`, " @@ -18210,13 +18252,13 @@ msgid "" msgstr "" #. type: Bullet: '- ' -#: ../text/chapter6.md:375 +#: ../text/chapter6.md:413 #, markdown-text msgid "`a => b` applies the _constraint_ `a` to the type `b`." msgstr "" #. type: Plain text -#: ../text/chapter6.md:377 +#: ../text/chapter6.md:415 #, markdown-text msgid "" "The PureScript compiler will try to infer constrained types when a type " @@ -18225,7 +18267,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:379 +#: ../text/chapter6.md:417 #, markdown-text msgid "" "To see this, try using one of the standard type classes like `Semiring` in " @@ -18233,7 +18275,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:380 +#: ../text/chapter6.md:418 #, no-wrap msgid "" "> import Prelude\n" @@ -18243,7 +18285,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:388 +#: ../text/chapter6.md:426 #, markdown-text, no-wrap msgid "" "Here, we might have annotated this function as `Int -> Int` or `Number -> " @@ -18252,13 +18294,13 @@ msgid "" msgstr "" #. type: Title ## -#: ../text/chapter6.md:389 +#: ../text/chapter6.md:427 #, markdown-text, no-wrap msgid "Instance Dependencies" msgstr "" #. type: Plain text -#: ../text/chapter6.md:392 +#: ../text/chapter6.md:430 #, markdown-text msgid "" "Just as the implementation of functions can depend on type class instances " @@ -18269,7 +18311,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:394 +#: ../text/chapter6.md:432 #, markdown-text msgid "" "For example, consider the `Show` type class. We can write a type class " @@ -18278,7 +18320,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:395 +#: ../text/chapter6.md:433 #, no-wrap msgid "" "instance Show a => Show (Array a) where\n" @@ -18286,7 +18328,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:401 +#: ../text/chapter6.md:439 #, markdown-text, no-wrap msgid "" "If a type class instance depends on multiple other instances, those " @@ -18295,7 +18337,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:402 +#: ../text/chapter6.md:440 #, no-wrap msgid "" "instance (Show a, Show b) => Show (Either a b) where\n" @@ -18303,13 +18345,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:408 +#: ../text/chapter6.md:446 #, markdown-text msgid "These two type class instances are provided in the `prelude` library." msgstr "" #. type: Plain text -#: ../text/chapter6.md:410 +#: ../text/chapter6.md:448 #, markdown-text msgid "" "When the program is compiled, the correct type class instance for `Show` is " @@ -18319,7 +18361,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:414 +#: ../text/chapter6.md:452 #, markdown-text msgid "" "(Easy) The following declaration defines a type of non-empty arrays of " @@ -18327,7 +18369,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:418 +#: ../text/chapter6.md:456 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -18337,7 +18379,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:420 +#: ../text/chapter6.md:458 #, markdown-text, no-wrap msgid "" " Write an `Eq` instance for the type `NonEmpty a` that reuses the " @@ -18346,7 +18388,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:422 +#: ../text/chapter6.md:460 #, markdown-text msgid "" "(Medium) Write a `Semigroup` instance for `NonEmpty a` by reusing the " @@ -18354,13 +18396,13 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:424 +#: ../text/chapter6.md:462 #, markdown-text msgid "(Medium) Write a `Functor` instance for `NonEmpty`." msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:426 +#: ../text/chapter6.md:464 #, markdown-text msgid "" "(Medium) Given any type `a` with an instance of `Ord`, we can add a new " @@ -18368,7 +18410,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:430 +#: ../text/chapter6.md:468 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -18378,7 +18420,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:432 +#: ../text/chapter6.md:470 #, markdown-text, no-wrap msgid "" " Write an `Ord` instance for `Extended a` that reuses the `Ord` instance " @@ -18386,7 +18428,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:434 +#: ../text/chapter6.md:472 #, markdown-text msgid "" "(Difficult) Write a `Foldable` instance for `NonEmpty`. _Hint_: reuse the " @@ -18394,7 +18436,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:436 +#: ../text/chapter6.md:474 #, markdown-text msgid "" "(Difficult) Given a type constructor `f` which defines an ordered container " @@ -18403,7 +18445,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:440 +#: ../text/chapter6.md:478 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -18413,7 +18455,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:442 +#: ../text/chapter6.md:480 #, markdown-text, no-wrap msgid "" " The container `OneMore f` also has an ordering, where the new element " @@ -18422,7 +18464,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:447 +#: ../text/chapter6.md:485 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -18433,7 +18475,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:449 +#: ../text/chapter6.md:487 #, markdown-text msgid "" "(Medium) Write a `dedupShapes :: Array Shape -> Array Shape` function that " @@ -18441,7 +18483,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:451 +#: ../text/chapter6.md:489 #, markdown-text msgid "" "(Medium) Write a `dedupShapesFast` function which is the same as " @@ -18449,13 +18491,13 @@ msgid "" msgstr "" #. type: Title ## -#: ../text/chapter6.md:452 +#: ../text/chapter6.md:490 #, markdown-text, no-wrap msgid "Multi-Parameter Type Classes" msgstr "" #. type: Plain text -#: ../text/chapter6.md:455 +#: ../text/chapter6.md:493 #, markdown-text msgid "" "It's not the case that a type class can only take a single type as an " @@ -18464,13 +18506,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:457 +#: ../text/chapter6.md:495 #, markdown-text msgid "Let's see an example of a type class with two type arguments." msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:458 +#: ../text/chapter6.md:496 #, no-wrap msgid "" "module Stream where\n" @@ -18490,7 +18532,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:476 +#: ../text/chapter6.md:514 #, markdown-text msgid "" "The `Stream` module defines a class `Stream` which identifies types that " @@ -18499,7 +18541,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:478 +#: ../text/chapter6.md:516 #, markdown-text msgid "" "Note that the `Stream` type class is parameterized not only by the type of " @@ -18508,7 +18550,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:480 +#: ../text/chapter6.md:518 #, markdown-text msgid "" "The module defines two type class instances: an instance for arrays, where " @@ -18517,7 +18559,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:482 +#: ../text/chapter6.md:520 #, markdown-text msgid "" "We can write functions that work over arbitrary streams. For example, here " @@ -18526,7 +18568,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:483 +#: ../text/chapter6.md:521 #, no-wrap msgid "" "import Prelude\n" @@ -18540,7 +18582,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:495 +#: ../text/chapter6.md:533 #, markdown-text msgid "" "Try using `foldStream` in PSCi for different types of `Stream` and different " @@ -18548,13 +18590,13 @@ msgid "" msgstr "" #. type: Title ## -#: ../text/chapter6.md:496 +#: ../text/chapter6.md:534 #, markdown-text, no-wrap msgid "Functional Dependencies" msgstr "" #. type: Plain text -#: ../text/chapter6.md:499 +#: ../text/chapter6.md:537 #, markdown-text msgid "" "Multi-parameter type classes can be very useful but can easily lead to " @@ -18564,19 +18606,19 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:500 +#: ../text/chapter6.md:538 #, no-wrap msgid "genericTail xs = map _.tail (uncons xs)\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:505 +#: ../text/chapter6.md:543 #, markdown-text msgid "This gives a somewhat confusing error message:" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:506 +#: ../text/chapter6.md:544 #, no-wrap msgid "" "The inferred type\n" @@ -18588,7 +18630,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:515 +#: ../text/chapter6.md:553 #, markdown-text msgid "" "The problem is that the `genericTail` function does not use the `element` " @@ -18597,7 +18639,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:517 +#: ../text/chapter6.md:555 #, markdown-text msgid "" "Worse still, we cannot even use `genericTail` by applying it to a specific " @@ -18605,7 +18647,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:518 +#: ../text/chapter6.md:556 #, no-wrap msgid "" "> map _.tail (uncons \"testing\")\n" @@ -18619,7 +18661,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:529 +#: ../text/chapter6.md:567 #, markdown-text msgid "" "Here, we might expect the compiler to choose the `streamString` " @@ -18628,7 +18670,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:531 +#: ../text/chapter6.md:569 #, markdown-text msgid "" "The compiler cannot make that deduction automatically or commit to the " @@ -18637,7 +18679,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:532 +#: ../text/chapter6.md:570 #, no-wrap msgid "" "class Stream stream element | stream -> element where\n" @@ -18645,7 +18687,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:538 +#: ../text/chapter6.md:576 #, markdown-text, no-wrap msgid "" "Here, `stream -> element` is called a _functional dependency_. A functional " @@ -18657,7 +18699,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:540 +#: ../text/chapter6.md:578 #, markdown-text msgid "" "This hint is enough for the compiler to infer the correct type for our " @@ -18665,7 +18707,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:541 +#: ../text/chapter6.md:579 #, no-wrap msgid "" "> :type genericTail\n" @@ -18677,7 +18719,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:550 +#: ../text/chapter6.md:588 #, markdown-text msgid "" "Functional dependencies can be useful when designing certain APIs using " @@ -18685,13 +18727,13 @@ msgid "" msgstr "" #. type: Title ## -#: ../text/chapter6.md:551 +#: ../text/chapter6.md:589 #, markdown-text, no-wrap msgid "Nullary Type Classes" msgstr "" #. type: Plain text -#: ../text/chapter6.md:554 +#: ../text/chapter6.md:592 #, markdown-text msgid "" "We can even define type classes with zero-type arguments! These correspond " @@ -18700,7 +18742,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:556 +#: ../text/chapter6.md:594 #, markdown-text msgid "" "An important example is the `Partial` class we saw earlier when discussing " @@ -18711,7 +18753,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:557 +#: ../text/chapter6.md:595 #, no-wrap msgid "" "head :: forall a. Partial => Array a -> a\n" @@ -18720,7 +18762,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:564 +#: ../text/chapter6.md:602 #, markdown-text msgid "" "Note that there is no instance defined for the `Partial` type class! Doing " @@ -18729,7 +18771,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:565 +#: ../text/chapter6.md:603 #, no-wrap msgid "" "> head [1, 2, 3]\n" @@ -18740,7 +18782,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:574 +#: ../text/chapter6.md:612 #, markdown-text msgid "" "Instead, we can republish the `Partial` constraint for any functions making " @@ -18748,7 +18790,7 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:575 +#: ../text/chapter6.md:613 #, no-wrap msgid "" "secondElement :: forall a. Partial => Array a -> a\n" @@ -18756,7 +18798,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:581 +#: ../text/chapter6.md:619 #, markdown-text msgid "" "We've already seen the `unsafePartial` function, which allows us to treat a " @@ -18765,13 +18807,13 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:582 +#: ../text/chapter6.md:620 #, no-wrap msgid "unsafePartial :: forall a. (Partial => a) -> a\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:587 +#: ../text/chapter6.md:625 #, markdown-text msgid "" "Note that the `Partial` constraint appears _inside the parentheses_ on the " @@ -18780,7 +18822,7 @@ msgid "" msgstr "" #. type: Fenced code block (text) -#: ../text/chapter6.md:588 +#: ../text/chapter6.md:626 #, no-wrap msgid "" "> unsafePartial head [1, 2, 3]\n" @@ -18791,13 +18833,13 @@ msgid "" msgstr "" #. type: Title ## -#: ../text/chapter6.md:596 +#: ../text/chapter6.md:634 #, markdown-text, no-wrap msgid "Superclasses" msgstr "" #. type: Plain text -#: ../text/chapter6.md:599 +#: ../text/chapter6.md:637 #, markdown-text msgid "" "Just as we can express relationships between type class instances by making " @@ -18806,7 +18848,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:601 +#: ../text/chapter6.md:639 #, markdown-text, no-wrap msgid "" "We say that one type class is a superclass of another if every instance of " @@ -18816,7 +18858,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:603 +#: ../text/chapter6.md:641 #, markdown-text msgid "" "We've [already seen an example of superclass relationships](#ord): the `Eq` " @@ -18829,20 +18871,20 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:605 +#: ../text/chapter6.md:643 #, markdown-text msgid "" "In general, it makes sense to define a superclass relationship when the laws " "for the subclass mention the superclass members. For example, for any pair " -"of Ord and Eq instances, it is reasonable to assume that if two values are " -"equal under the `Eq` instance, then the `compare` function should return " +"of `Ord` and `Eq` instances, it is reasonable to assume that if two values " +"are equal under the `Eq` instance, then the `compare` function should return " "`EQ`. In other words, `a == b` should be true exactly when `compare a b` " "evaluates to `EQ`. This relationship on the level of laws justifies the " "superclass relationship between `Eq` and `Ord`." msgstr "" #. type: Plain text -#: ../text/chapter6.md:607 +#: ../text/chapter6.md:645 #, markdown-text msgid "" "Another reason to define a superclass relationship is when there is a clear " @@ -18851,7 +18893,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:611 +#: ../text/chapter6.md:649 #, markdown-text msgid "" "(Medium) Define a partial function `unsafeMaximum :: Partial => Array Int -> " @@ -18861,7 +18903,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:613 +#: ../text/chapter6.md:651 #, markdown-text msgid "" "(Medium) The `Action` class is a multi-parameter type class that defines an " @@ -18869,7 +18911,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:617 +#: ../text/chapter6.md:655 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -18879,7 +18921,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:619 +#: ../text/chapter6.md:657 #, markdown-text, no-wrap msgid "" " An _action_ is a function that describes how monoidal values are used to " @@ -18888,19 +18930,19 @@ msgid "" msgstr "" #. type: Bullet: ' - ' -#: ../text/chapter6.md:622 +#: ../text/chapter6.md:660 #, markdown-text msgid "`act mempty a = a`" msgstr "" #. type: Bullet: ' - ' -#: ../text/chapter6.md:622 +#: ../text/chapter6.md:660 #, markdown-text msgid "`act (m1 <> m2) a = act m1 (act m2 a)`" msgstr "" #. type: Plain text -#: ../text/chapter6.md:624 +#: ../text/chapter6.md:662 #, markdown-text, no-wrap msgid "" " Applying an empty action is a no-op. And applying two actions in " @@ -18909,13 +18951,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:626 +#: ../text/chapter6.md:664 #, markdown-text, no-wrap msgid " For example, the natural numbers form a monoid under multiplication:\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:629 +#: ../text/chapter6.md:667 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -18924,7 +18966,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:631 +#: ../text/chapter6.md:669 #, markdown-text, no-wrap msgid "" " {{#include " @@ -18932,7 +18974,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:634 +#: ../text/chapter6.md:672 #, markdown-text, no-wrap msgid "" " {{#include " @@ -18941,13 +18983,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:636 +#: ../text/chapter6.md:674 #, markdown-text, no-wrap msgid " Write an instance that implements this action:\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:641 +#: ../text/chapter6.md:679 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -18958,13 +19000,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:643 +#: ../text/chapter6.md:681 #, markdown-text, no-wrap msgid " Remember, your instance must satisfy the laws listed above.\n" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:645 +#: ../text/chapter6.md:683 #, markdown-text msgid "" "(Difficult) There are multiple ways to implement an instance of `Action " @@ -18974,7 +19016,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:647 +#: ../text/chapter6.md:685 #, markdown-text msgid "" "(Medium) Write an `Action` instance that repeats an input string some number " @@ -18982,7 +19024,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:652 +#: ../text/chapter6.md:690 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -18993,7 +19035,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:654 +#: ../text/chapter6.md:692 #, markdown-text, no-wrap msgid "" " _Hint_: Search Pursuit for a helper-function with the signature [`String " @@ -19003,13 +19045,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:656 +#: ../text/chapter6.md:694 #, markdown-text, no-wrap msgid " Does this instance satisfy the laws listed above?\n" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:658 +#: ../text/chapter6.md:696 #, markdown-text msgid "" "(Medium) Write an instance `Action m a => Action m (Array a)`, where the " @@ -19017,7 +19059,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:660 +#: ../text/chapter6.md:698 #, markdown-text msgid "" "(Difficult) Given the following newtype, write an instance for `Action m " @@ -19025,7 +19067,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:664 +#: ../text/chapter6.md:702 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -19034,7 +19076,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:666 +#: ../text/chapter6.md:704 #, markdown-text, no-wrap msgid "" " _Note_: The testing framework requires `Show` and `Eq` instances for the " @@ -19045,7 +19087,7 @@ msgid "" msgstr "" #. type: Bullet: '1. ' -#: ../text/chapter6.md:668 +#: ../text/chapter6.md:706 #, markdown-text msgid "" "(Difficult) Should the arguments of the multi-parameter type class `Action` " @@ -19054,13 +19096,13 @@ msgid "" msgstr "" #. type: Title ## -#: ../text/chapter6.md:669 +#: ../text/chapter6.md:707 #, markdown-text, no-wrap msgid "A Type Class for Hashes" msgstr "" #. type: Plain text -#: ../text/chapter6.md:672 +#: ../text/chapter6.md:710 #, markdown-text msgid "" "In the last section of this chapter, we will use the lessons from the rest " @@ -19068,7 +19110,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:674 +#: ../text/chapter6.md:712 #, markdown-text, no-wrap msgid "" "> Note that this library is for demonstration purposes only and is not " @@ -19076,13 +19118,13 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:676 +#: ../text/chapter6.md:714 #, markdown-text msgid "What properties might we expect of a hash function?" msgstr "" #. type: Bullet: '- ' -#: ../text/chapter6.md:679 +#: ../text/chapter6.md:717 #, markdown-text msgid "" "A hash function should be deterministic and map equal values to equal hash " @@ -19090,7 +19132,7 @@ msgid "" msgstr "" #. type: Bullet: '- ' -#: ../text/chapter6.md:679 +#: ../text/chapter6.md:717 #, markdown-text msgid "" "A hash function should distribute its results approximately uniformly over " @@ -19098,7 +19140,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:681 +#: ../text/chapter6.md:719 #, markdown-text msgid "" "The first property looks a lot like a law for a type class, whereas the " @@ -19108,19 +19150,19 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:682 +#: ../text/chapter6.md:720 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:Hashable}}\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:687 +#: ../text/chapter6.md:725 #, markdown-text msgid "with the associated law that `a == b` implies `hash a == hash b`." msgstr "" #. type: Plain text -#: ../text/chapter6.md:689 +#: ../text/chapter6.md:727 #, markdown-text msgid "" "We'll spend the rest of this section building a library of instances and " @@ -19128,19 +19170,19 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:691 +#: ../text/chapter6.md:729 #, markdown-text msgid "We will need a way to combine hash codes in a deterministic way:" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:692 +#: ../text/chapter6.md:730 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:combineHashes}}\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:697 +#: ../text/chapter6.md:735 #, markdown-text msgid "" "The `combineHashes` function will mix two hash codes and redistribute the " @@ -19148,7 +19190,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:699 +#: ../text/chapter6.md:737 #, markdown-text msgid "" "Let's write a function that uses the `Hashable` constraint to restrict the " @@ -19158,13 +19200,13 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:700 +#: ../text/chapter6.md:738 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashEqual}}\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:705 +#: ../text/chapter6.md:743 #, markdown-text msgid "" "This function uses the `on` function from `Data.Function` to define " @@ -19174,7 +19216,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:707 +#: ../text/chapter6.md:745 #, markdown-text msgid "" "Let's write some `Hashable` instances for some primitive types. Let's start " @@ -19183,13 +19225,13 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:708 +#: ../text/chapter6.md:746 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashInt}}\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:713 +#: ../text/chapter6.md:751 #, markdown-text msgid "" "We can also define a simple instance for `Boolean` values using pattern " @@ -19197,13 +19239,13 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:714 +#: ../text/chapter6.md:752 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashBoolean}}\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:719 +#: ../text/chapter6.md:757 #, markdown-text msgid "" "With an instance for hashing integers, we can create an instance for hashing " @@ -19211,13 +19253,13 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:720 +#: ../text/chapter6.md:758 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashChar}}\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:725 +#: ../text/chapter6.md:763 #, markdown-text msgid "" "To define an instance for arrays, we can `map` the `hash` function over the " @@ -19227,13 +19269,13 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:726 +#: ../text/chapter6.md:764 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashArray}}\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:731 +#: ../text/chapter6.md:769 #, markdown-text msgid "" "Notice how we build up instances using the simpler instances we have already " @@ -19242,13 +19284,13 @@ msgid "" msgstr "" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:732 +#: ../text/chapter6.md:770 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashString}}\n" msgstr "" #. type: Plain text -#: ../text/chapter6.md:737 +#: ../text/chapter6.md:775 #, markdown-text msgid "" "How can we prove that these `Hashable` instances satisfy the type class law " @@ -19259,7 +19301,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:739 +#: ../text/chapter6.md:777 #, markdown-text msgid "" "What about some more interesting types? To prove the type class law for the " @@ -19273,7 +19315,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:741 +#: ../text/chapter6.md:779 #, markdown-text msgid "" "The source code for this chapter includes several other examples of " @@ -19281,7 +19323,7 @@ msgid "" msgstr "" #. type: Bullet: ' 1. ' -#: ../text/chapter6.md:747 +#: ../text/chapter6.md:785 #, markdown-text msgid "" "(Easy) Use PSCi to test the hash functions for each of the defined " @@ -19289,7 +19331,7 @@ msgid "" msgstr "" #. type: Bullet: ' 1. ' -#: ../text/chapter6.md:747 +#: ../text/chapter6.md:785 #, markdown-text msgid "" "(Medium) Write a function `arrayHasDuplicates`, which tests if an array has " @@ -19300,7 +19342,7 @@ msgid "" msgstr "" #. type: Bullet: ' 1. ' -#: ../text/chapter6.md:747 +#: ../text/chapter6.md:785 #, markdown-text msgid "" "(Medium) Write a `Hashable` instance for the following newtype which " @@ -19308,7 +19350,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:750 +#: ../text/chapter6.md:788 #, markdown-text, no-wrap msgid "" " ```haskell\n" @@ -19316,7 +19358,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:753 +#: ../text/chapter6.md:791 #, markdown-text, no-wrap msgid "" " {{#include " @@ -19325,7 +19367,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:756 +#: ../text/chapter6.md:794 #, markdown-text, no-wrap msgid "" " The newtype `Hour` and its `Eq` instance represent the type of integers " @@ -19336,7 +19378,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:760 +#: ../text/chapter6.md:798 #, markdown-text msgid "" "In this chapter, we've been introduced to _type classes_, a type-oriented " @@ -19346,7 +19388,7 @@ msgid "" msgstr "" #. type: Plain text -#: ../text/chapter6.md:761 +#: ../text/chapter6.md:799 #, markdown-text msgid "" "This chapter also introduced type class laws, a technique for proving " diff --git a/translation/po/ja.po b/translation/po/ja.po index a80966cf..19abac14 100644 --- a/translation/po/ja.po +++ b/translation/po/ja.po @@ -15,8 +15,8 @@ msgid "" msgstr "" "Project-Id-Version: com.github.gemmaro.purescript-book.v0.1.0\n" -"POT-Creation-Date: 2023-11-12 11:27+0900\n" -"PO-Revision-Date: 2023-11-12 11:37+0900\n" +"POT-Creation-Date: 2023-11-30 19:18+0900\n" +"PO-Revision-Date: 2023-11-30 19:31+0900\n" "Last-Translator: gemmaro \n" "Language-Team: none\n" "Language: ja\n" @@ -1934,8 +1934,8 @@ msgstr "本書の残りの例では入れ子の関数の代わりに矢印関数 #: ../text/chapter4.md:101 ../text/chapter4.md:230 ../text/chapter4.md:394 #: ../text/chapter4.md:467 ../text/chapter4.md:526 ../text/chapter5.md:72 #: ../text/chapter5.md:183 ../text/chapter5.md:373 ../text/chapter5.md:531 -#: ../text/chapter5.md:625 ../text/chapter6.md:130 ../text/chapter6.md:321 -#: ../text/chapter6.md:411 ../text/chapter6.md:608 ../text/chapter6.md:742 +#: ../text/chapter5.md:625 ../text/chapter6.md:168 ../text/chapter6.md:359 +#: ../text/chapter6.md:449 ../text/chapter6.md:646 ../text/chapter6.md:780 #: ../text/chapter7.md:381 ../text/chapter7.md:540 ../text/chapter7.md:642 #: ../text/chapter8.md:308 ../text/chapter8.md:667 ../text/chapter8.md:974 #: ../text/chapter9.md:87 ../text/chapter9.md:134 ../text/chapter9.md:201 @@ -4233,7 +4233,7 @@ msgstr "" #: ../text/chapter10.md:1083 ../text/chapter11.md:963 ../text/chapter12.md:594 #: ../text/chapter13.md:401 ../text/chapter14.md:720 ../text/chapter2.md:128 #: ../text/chapter3.md:782 ../text/chapter4.md:531 ../text/chapter5.md:641 -#: ../text/chapter6.md:757 ../text/chapter7.md:691 ../text/chapter8.md:1001 +#: ../text/chapter6.md:795 ../text/chapter7.md:691 ../text/chapter8.md:1001 #: ../text/chapter9.md:238 #, no-wrap msgid "Conclusion" @@ -20966,25 +20966,102 @@ msgstr "" #. type: Plain text #: ../text/chapter6.md:51 msgid "" -"This code declares a type class instance called `showBoolean` – in " -"PureScript, type class instances can be named to aid the readability of the " -"generated JavaScript. We say that the `Boolean` type _belongs to the `Show` " -"type class_." +"This code declares a type class instance; we say that the `Boolean` type " +"_belongs to the `Show` type class_." msgstr "" -"このコードは `showBool​​ean`という名前の型クラスのインスタンスを宣言します。\n" -"PureScriptでは、生成されたJavaScriptの可読性を良くするために、型クラスインス" -"タンスに名前を付けられます。\n" -"このとき、`Boolean`型は *`Show`型クラスに属している* といいます。" +"このコードは型クラスのインスタンスを宣言します。\n" +"`Boolean`型は *`Show`型クラスに属すもの* としています。" #. type: Plain text -#: ../text/chapter6.md:53 +#: ../text/chapter6.md:89 +#, no-wrap msgid "" -"We can try out the `Show` type class in PSCi, by showing a few values with " +"> If you're wondering, the generated JS code looks like this:\n" +">\n" +"> ```javascript\n" +"> var showBoolean = {\n" +"> show: function (v) {\n" +"> if (v) {\n" +"> return \"true\";\n" +"> };\n" +"> if (!v) {\n" +"> return \"false\";\n" +"> };\n" +"> throw new Error(\"Failed pattern match at ...\");\n" +"> }\n" +"> };\n" +"> ```\n" +">\n" +"> If you're unhappy with the generated name, you can give names to type class instances. For example:\n" +">\n" +"> ```haskell\n" +"> instance myShowBoolean :: Show Boolean where\n" +"> show true = \"true\"\n" +"> show false = \"false\"\n" +"> ```\n" +">\n" +"> ```javascript\n" +"> var myShowBoolean = {\n" +"> show: function (v) {\n" +"> if (v) {\n" +"> return \"true\";\n" +"> };\n" +"> if (!v) {\n" +"> return \"false\";\n" +"> };\n" +"> throw new Error(\"Failed pattern match at ...\");\n" +"> }\n" +"> };\n" +"> ```\n" +msgstr "" +"> ピンとこなければ、生成されるJSのコードは以下のようになります。\n" +">\n" +"> ```javascript\n" +"> var showBoolean = {\n" +"> show: function (v) {\n" +"> if (v) {\n" +"> return \"true\";\n" +"> };\n" +"> if (!v) {\n" +"> return \"false\";\n" +"> };\n" +"> throw new Error(\"Failed pattern match at ...\");\n" +"> }\n" +"> };\n" +"> ```\n" +">\n" +"> 生成される名前が気に入らなければ、型クラスインスタンスに名前を与えられます。\n" +"> 例えば次のようにします。\n" +">\n" +"> ```haskell\n" +"> instance myShowBoolean :: Show Boolean where\n" +"> show true = \"true\"\n" +"> show false = \"false\"\n" +"> ```\n" +">\n" +"> ```javascript\n" +"> var myShowBoolean = {\n" +"> show: function (v) {\n" +"> if (v) {\n" +"> return \"true\";\n" +"> };\n" +"> if (!v) {\n" +"> return \"false\";\n" +"> };\n" +"> throw new Error(\"Failed pattern match at ...\");\n" +"> }\n" +"> };\n" +"> ```\n" + +#. type: Plain text +#: ../text/chapter6.md:91 +msgid "" +"We can try out the `Show` type class in PSCi by showing a few values with " "different types:" -msgstr "PSCiで、いろいろな型の値を`Show`型クラスを使って表示してみましょう。" +msgstr "PSCiでいろいろな型の値を`Show`型クラスを使って表示してみましょう。" #. type: Fenced code block (text) -#: ../text/chapter6.md:54 +#: ../text/chapter6.md:92 #, no-wrap msgid "" "> import Prelude\n" @@ -21010,7 +21087,7 @@ msgstr "" "\"\\\"Hello World\\\"\"\n" #. type: Plain text -#: ../text/chapter6.md:68 +#: ../text/chapter6.md:106 msgid "" "These examples demonstrate how to `show` values of various primitive types, " "but we can also `show` values with more complicated types:" @@ -21019,7 +21096,7 @@ msgstr "" "できます。" #. type: Fenced code block (text) -#: ../text/chapter6.md:69 +#: ../text/chapter6.md:107 #, no-wrap msgid "" "> import Data.Tuple\n" @@ -21043,7 +21120,7 @@ msgstr "" "\"(Just \\\"testing\\\")\"\n" #. type: Plain text -#: ../text/chapter6.md:82 +#: ../text/chapter6.md:120 msgid "" "The output of `show` should be a string that you can paste back into the " "repl (or `.purs` file) to recreate the item being shown. Here we'll use " @@ -21059,7 +21136,7 @@ msgstr "" "第8章で`log`のような`Effect`を調べるときに押さえます。" #. type: Fenced code block (text) -#: ../text/chapter6.md:83 +#: ../text/chapter6.md:121 #, no-wrap msgid "" "> import Effect.Console\n" @@ -21083,7 +21160,7 @@ msgstr "" "unit\n" #. type: Plain text -#: ../text/chapter6.md:96 +#: ../text/chapter6.md:134 msgid "" "If we try to show a value of type `Data.Either`, we get an interesting error " "message:" @@ -21091,7 +21168,7 @@ msgstr "" "型 `Data.Either`の値を表示しようとすると、興味深いエラー文言が表示されます。" #. type: Fenced code block (text) -#: ../text/chapter6.md:97 +#: ../text/chapter6.md:135 #, no-wrap msgid "" "> import Data.Either\n" @@ -21113,7 +21190,7 @@ msgstr "" "has type variables which are not mentioned in the body of the type. Consider adding a type annotation.\n" #. type: Plain text -#: ../text/chapter6.md:109 +#: ../text/chapter6.md:147 msgid "" "The problem here is not that there is no `Show` instance for the type we " "intended to `show`, but rather that PSCi could not infer the type. This is " @@ -21124,7 +21201,7 @@ msgstr "" "これは推論された型で*未知の型*`a`とされていることが示しています。" #. type: Plain text -#: ../text/chapter6.md:111 +#: ../text/chapter6.md:149 msgid "" "We can annotate the expression with a type using the `::` operator, so that " "PSCi can choose the correct type class instance:" @@ -21133,7 +21210,7 @@ msgstr "" "うにできます。" #. type: Fenced code block (text) -#: ../text/chapter6.md:112 +#: ../text/chapter6.md:150 #, no-wrap msgid "" "> show (Left 10 :: Either Int String)\n" @@ -21143,7 +21220,7 @@ msgstr "" "\"(Left 10)\"\n" #. type: Plain text -#: ../text/chapter6.md:118 +#: ../text/chapter6.md:156 #, no-wrap msgid "Some types do not have a `Show` instance defined at all. One example of this is the function type `->`. If we try to `show` a function from `Int` to `Int`, we get an appropriate error message from the type checker:\n" msgstr "" @@ -21152,7 +21229,7 @@ msgstr "" "`Int`から `Int`への関数を `show`しようとすると、型検証器によってその旨のエラー文言が表示されます。\n" #. type: Fenced code block (text) -#: ../text/chapter6.md:119 +#: ../text/chapter6.md:157 #, no-wrap msgid "" "> import Prelude\n" @@ -21170,7 +21247,7 @@ msgstr "" " Data.Show.Show (Int -> Int)\n" #. type: Plain text -#: ../text/chapter6.md:129 +#: ../text/chapter6.md:167 msgid "" "Type class instances can be defined in one of two places: in the same module " "that the type class is defined, or in the same module that the type " @@ -21191,7 +21268,7 @@ msgstr "" "の定義を自分の`MySolutions`モジュールに複製する必要があります。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:133 +#: ../text/chapter6.md:171 msgid "" "(Easy) Define a `Show` instance for `Point`. Match the same output as the " "`showPoint` function from the previous chapter. _Note:_ Point is now a " @@ -21206,7 +21283,7 @@ msgstr "" "こうでもしないとレコードへの既定の`Show`インスタンスから逃れられません。" #. type: Plain text -#: ../text/chapter6.md:137 +#: ../text/chapter6.md:175 #, no-wrap msgid "" " ```haskell\n" @@ -21218,13 +21295,13 @@ msgstr "" " ```\n" #. type: Title ## -#: ../text/chapter6.md:138 +#: ../text/chapter6.md:176 #, no-wrap msgid "Common Type Classes" msgstr "よく見かける型クラス" #. type: Plain text -#: ../text/chapter6.md:141 +#: ../text/chapter6.md:179 msgid "" "In this section, we'll look at some standard type classes defined in the " "Prelude and standard libraries. These type classes form the basis of many " @@ -21238,13 +21315,13 @@ msgstr "" "そのため、これらの関数の基本についてよく理解しておくことを強くお勧めします。" #. type: Title ### -#: ../text/chapter6.md:142 +#: ../text/chapter6.md:180 #, no-wrap msgid "Eq" msgstr "Eq" #. type: Plain text -#: ../text/chapter6.md:145 +#: ../text/chapter6.md:183 msgid "" "The `Eq` type class defines the `eq` function, which tests two values for " "equality. The `==` operator is actually an alias for `eq`." @@ -21254,7 +21331,7 @@ msgstr "" "実は`==`演算子は`eq`の別名です。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:146 +#: ../text/chapter6.md:184 #, no-wrap msgid "" "class Eq a where\n" @@ -21264,7 +21341,7 @@ msgstr "" " eq :: a -> a -> Boolean\n" #. type: Plain text -#: ../text/chapter6.md:152 +#: ../text/chapter6.md:190 msgid "" "In either case, the two arguments must have the same type: it does not make " "sense to compare two values of different types for equality." @@ -21273,12 +21350,12 @@ msgstr "" "異なる型の2つの値を等値性に関して比較しても意味がありません。" #. type: Plain text -#: ../text/chapter6.md:154 +#: ../text/chapter6.md:192 msgid "Try out the `Eq` type class in PSCi:" msgstr "PSCiで `Eq`型クラスを試してみましょう。" #. type: Fenced code block (text) -#: ../text/chapter6.md:155 +#: ../text/chapter6.md:193 #, no-wrap msgid "" "> 1 == 2\n" @@ -21294,13 +21371,13 @@ msgstr "" "true\n" #. type: Title ### -#: ../text/chapter6.md:163 +#: ../text/chapter6.md:201 #, no-wrap msgid "Ord" msgstr "Ord" #. type: Plain text -#: ../text/chapter6.md:166 +#: ../text/chapter6.md:204 #, no-wrap msgid "The `Ord` type class defines the `compare` function, which can be used to compare two values, for types that support ordering. The comparison operators `<` and `>` along with their non-strict companions `<=` and `>=`, can be defined in terms of `compare`.\n" msgstr "" @@ -21309,16 +21386,17 @@ msgstr "" "比較演算子`<`、`>`と厳密な大小比較ではない`<=`、`>=`は`compare`を用いて定義されます。\n" #. type: Plain text -#: ../text/chapter6.md:168 +#: ../text/chapter6.md:206 #, no-wrap -msgid "_Note_: In the example below, the class signature contains `<=`. This usage of `<=` in this context indicates that Eq is a subclass of Ord and is not intended to represent the use of `<=` as a comparison operator. See the section [Superclasses](#superclasses) below.\n" +msgid "_Note_: In the example below, the class signature contains `<=`. This usage of `<=` in this context indicates that `Eq` is a superclass of `Ord` and is not intended to represent the use of `<=` as a comparison operator. See the section [Superclasses](#superclasses) below.\n" msgstr "" -"*補足*：以下の例ではクラスシグネチャに`<=`が含まれています。\n" -"この文脈での`<=`の使われ方はEqがOrdの上位クラスであり、比較演算子としての`<=`の用途を表す意図はありません。\n" +"*補足*：\n" +"以下の例ではクラスシグネチャに`<=`が含まれています。\n" +"この文脈での`<=`の使われ方は、`Eq`が`Ord`の上位クラスであり、比較演算子としての`<=`の用途を表す意図はありません。\n" "後述の[上位クラス](#上位クラス)の節を参照してください。\n" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:169 +#: ../text/chapter6.md:207 #, no-wrap msgid "" "data Ordering = LT | EQ | GT\n" @@ -21332,7 +21410,7 @@ msgstr "" " compare :: a -> a -> Ordering\n" #. type: Plain text -#: ../text/chapter6.md:177 +#: ../text/chapter6.md:215 msgid "" "The `compare` function compares two values and returns an `Ordering`, which " "has three alternatives:" @@ -21341,27 +21419,27 @@ msgstr "" "これには3つ選択肢があります。" #. type: Bullet: '- ' -#: ../text/chapter6.md:181 +#: ../text/chapter6.md:219 msgid "`LT` – if the first argument is less than the second." msgstr "`LT`- 最初の引数が2番目の値より小さいとき。" #. type: Bullet: '- ' -#: ../text/chapter6.md:181 +#: ../text/chapter6.md:219 msgid "`EQ` – if the first argument is equal to the second." msgstr "`EQ`- 最初の引数が2番目の値と等しいとき。" #. type: Bullet: '- ' -#: ../text/chapter6.md:181 +#: ../text/chapter6.md:219 msgid "`GT` – if the first argument is greater than the second." msgstr "`GT`- 最初の引数が2番目の値より大きいとき。" #. type: Plain text -#: ../text/chapter6.md:183 +#: ../text/chapter6.md:221 msgid "Again, we can try out the `compare` function in PSCi:" msgstr "ここでも`compare`関数についてPSCiで試してみましょう。" #. type: Fenced code block (text) -#: ../text/chapter6.md:184 +#: ../text/chapter6.md:222 #, no-wrap msgid "" "> compare 1 2\n" @@ -21377,13 +21455,13 @@ msgstr "" "LT\n" #. type: Title ### -#: ../text/chapter6.md:192 +#: ../text/chapter6.md:230 #, no-wrap msgid "Field" msgstr "Field" #. type: Plain text -#: ../text/chapter6.md:195 +#: ../text/chapter6.md:233 msgid "" "The `Field` type class identifies those types which support numeric " "operators such as addition, subtraction, multiplication, and division. It is " @@ -21396,7 +21474,7 @@ msgstr "" "す。" #. type: Plain text -#: ../text/chapter6.md:197 +#: ../text/chapter6.md:235 #, no-wrap msgid "> _Note_: Just like the `Eq` and `Ord` type classes, the `Field` type class has special support in the PureScript compiler, so that simple expressions such as `1 + 2 * 3` get translated into simple JavaScript, as opposed to function calls which dispatch based on a type class implementation.\n" msgstr "" @@ -21404,13 +21482,13 @@ msgstr "" "> 型クラスの実装に基いて呼び出される関数呼び出しとは対照的です。\n" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:198 +#: ../text/chapter6.md:236 #, no-wrap msgid "class EuclideanRing a <= Field a\n" msgstr "class EuclideanRing a <= Field a\n" #. type: Plain text -#: ../text/chapter6.md:203 +#: ../text/chapter6.md:241 msgid "" "The `Field` type class is composed from several more general _superclasses_. " "This allows us to talk abstractly about types that support some but not all " @@ -21429,7 +21507,7 @@ msgstr "" "スですが、`Ring`や`Field`のインスタンスではありません。" #. type: Plain text -#: ../text/chapter6.md:205 +#: ../text/chapter6.md:243 msgid "" "Superclasses will be explained later in this chapter, but the full [numeric " "type class hierarchy](https://a-guide-to-the-purescript-numeric-hierarchy." @@ -21447,13 +21525,13 @@ msgstr "" "ください。" #. type: Title ### -#: ../text/chapter6.md:206 +#: ../text/chapter6.md:244 #, no-wrap msgid "Semigroups and Monoids" msgstr "半群とモノイド" #. type: Plain text -#: ../text/chapter6.md:209 +#: ../text/chapter6.md:247 msgid "" "The `Semigroup` type class identifies those types which support an `append` " "operation to combine two values:" @@ -21462,7 +21540,7 @@ msgstr "" "示します。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:210 +#: ../text/chapter6.md:248 #, no-wrap msgid "" "class Semigroup a where\n" @@ -21472,7 +21550,7 @@ msgstr "" " append :: a -> a -> a\n" #. type: Plain text -#: ../text/chapter6.md:216 +#: ../text/chapter6.md:254 msgid "" "Strings form a semigroup under regular string concatenation, and so do " "arrays. The `prelude` package provides several other standard instances." @@ -21481,13 +21559,13 @@ msgstr "" "その他の標準的なインスタンスは`prelude`パッケージで提供されています。" #. type: Plain text -#: ../text/chapter6.md:218 +#: ../text/chapter6.md:256 #, no-wrap msgid "The `<>` concatenation operator, which we have already seen, is provided as an alias for `append`.\n" msgstr "以前に見た `<>`連結演算子は、 `append`の別名として提供されています。\n" #. type: Plain text -#: ../text/chapter6.md:220 +#: ../text/chapter6.md:258 msgid "" "The `Monoid` type class (provided by the `prelude` package) extends the " "`Semigroup` type class with the concept of an empty value, called `mempty`:" @@ -21496,7 +21574,7 @@ msgstr "" "の空の値の概念があり、`Semigroup`型クラスを拡張します。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:221 +#: ../text/chapter6.md:259 #, no-wrap msgid "" "class Semigroup m <= Monoid m where\n" @@ -21506,12 +21584,12 @@ msgstr "" " mempty :: m\n" #. type: Plain text -#: ../text/chapter6.md:227 +#: ../text/chapter6.md:265 msgid "Again, strings and arrays are simple examples of monoids." msgstr "ここでも文字列や配列はモノイドの簡単な例になっています。" #. type: Plain text -#: ../text/chapter6.md:229 +#: ../text/chapter6.md:267 msgid "" "A `Monoid` type class instance for a type describes how to _accumulate_ a " "result with that type by starting with an \"empty\" value and combining new " @@ -21525,7 +21603,7 @@ msgstr "" "PSCiで以下の通りです。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:230 +#: ../text/chapter6.md:268 #, no-wrap msgid "" "> import Prelude\n" @@ -21549,7 +21627,7 @@ msgstr "" "[1,2,3,4,5,6]\n" #. type: Plain text -#: ../text/chapter6.md:243 +#: ../text/chapter6.md:281 msgid "" "The `prelude` package provides many examples of monoids and semigroups, " "which we will use in the rest of the book." @@ -21558,13 +21636,13 @@ msgstr "" "本書で扱っていきます。" #. type: Title ### -#: ../text/chapter6.md:244 +#: ../text/chapter6.md:282 #, no-wrap msgid "Foldable" msgstr "Foldable" #. type: Plain text -#: ../text/chapter6.md:247 +#: ../text/chapter6.md:285 msgid "" "If the `Monoid` type class identifies those types which act as the result of " "a fold, then the `Foldable` type class identifies those type constructors " @@ -21574,7 +21652,7 @@ msgstr "" "は畳み込みの元のデータとして使えるような型構築子を示しています。" #. type: Plain text -#: ../text/chapter6.md:249 +#: ../text/chapter6.md:287 msgid "" "The `Foldable` type class is provided in the `foldable-traversable` package, " "which also contains instances for some standard containers such as arrays " @@ -21584,7 +21662,7 @@ msgstr "" "スタンスを含む`foldable-traversable`パッケージで提供されています。" #. type: Plain text -#: ../text/chapter6.md:251 +#: ../text/chapter6.md:289 msgid "" "The type signatures for the functions belonging to the `Foldable` class are " "a little more complicated than the ones we've seen so far:" @@ -21593,7 +21671,7 @@ msgstr "" "複雑です。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:252 +#: ../text/chapter6.md:290 #, no-wrap msgid "" "class Foldable f where\n" @@ -21607,7 +21685,7 @@ msgstr "" " foldMap :: forall a m. Monoid m => (a -> m) -> f a -> m\n" #. type: Plain text -#: ../text/chapter6.md:260 +#: ../text/chapter6.md:298 msgid "" "It is instructive to specialize to the case where `f` is the array type " "constructor. In this case, we can replace `f a` with `Array a` for any a, " @@ -21620,7 +21698,7 @@ msgstr "" "す。" #. type: Plain text -#: ../text/chapter6.md:262 +#: ../text/chapter6.md:300 #, no-wrap msgid "What about `foldMap`? Well, that becomes `forall a m. Monoid m => (a -> m) -> Array a -> m`. This type signature says that we can choose any type `m` for our result type, as long as that type is an instance of the `Monoid` type class. If we can provide a function that turns our array elements into values in that monoid, then we can accumulate over our array using the structure of the monoid and return a single value.\n" msgstr "" @@ -21630,12 +21708,12 @@ msgstr "" "配列の要素をそのモノイドの値へと変える関数を与えられれば、そのモノイドの構造を利用して配列上で累算し、1つの値にして返せます。\n" #. type: Plain text -#: ../text/chapter6.md:264 +#: ../text/chapter6.md:302 msgid "Let's try out `foldMap` in PSCi:" msgstr "それではPSCiで `foldMap`を試してみましょう。" #. type: Fenced code block (text) -#: ../text/chapter6.md:265 +#: ../text/chapter6.md:303 #, no-wrap msgid "" "> import Data.Foldable\n" @@ -21649,7 +21727,7 @@ msgstr "" "\"12345\"\n" #. type: Plain text -#: ../text/chapter6.md:273 +#: ../text/chapter6.md:311 msgid "" "Here, we choose the monoid for strings, which concatenates strings together, " "and the `show` function, which renders an `Int` as a `String`. Then, passing " @@ -21662,7 +21740,7 @@ msgstr "" "を得ました。" #. type: Plain text -#: ../text/chapter6.md:275 +#: ../text/chapter6.md:313 msgid "" "But arrays are not the only types that are foldable. `foldable-traversable` " "also defines `Foldable` instances for types like `Maybe` and `Tuple`, and " @@ -21676,13 +21754,13 @@ msgstr "" "`Foldable`は*順序付きコンテナ*の概念を見据えたものなのです。" #. type: Title ### -#: ../text/chapter6.md:276 +#: ../text/chapter6.md:314 #, no-wrap msgid "Functor and Type Class Laws" msgstr "関手と型クラス則" #. type: Plain text -#: ../text/chapter6.md:279 +#: ../text/chapter6.md:317 msgid "" "The Prelude also defines a collection of type classes that enable a " "functional style of programming with side-effects in PureScript: `Functor`, " @@ -21698,7 +21776,7 @@ msgstr "" "既に`map`関数の形で見たものです。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:280 +#: ../text/chapter6.md:318 #, no-wrap msgid "" "class Functor f where\n" @@ -21708,7 +21786,7 @@ msgstr "" " map :: forall a b. (a -> b) -> f a -> f b\n" #. type: Plain text -#: ../text/chapter6.md:286 +#: ../text/chapter6.md:324 #, no-wrap msgid "The `map` function (and its alias `<$>`) allows a function to be \"lifted\" over a data structure. The precise definition of the word \"lifted\" here depends on the data structure in question, but we have already seen its behavior for some simple types:\n" msgstr "" @@ -21716,7 +21794,7 @@ msgstr "" "ここで「持ち上げ」という言葉の具体的な定義は問題のデータ構造に依りますが、既に幾つかの単純な型についてその動作を見てきました。\n" #. type: Fenced code block (text) -#: ../text/chapter6.md:287 +#: ../text/chapter6.md:325 #, no-wrap msgid "" "> import Prelude\n" @@ -21742,7 +21820,7 @@ msgstr "" "(Just 7)\n" #. type: Plain text -#: ../text/chapter6.md:301 +#: ../text/chapter6.md:339 msgid "" "How can we understand the meaning of the `map` function, when it acts on " "many different structures, each in a different way?" @@ -21751,7 +21829,7 @@ msgstr "" "はどのように理解すればいいのでしょうか。" #. type: Plain text -#: ../text/chapter6.md:303 +#: ../text/chapter6.md:341 msgid "" "Well, we can build an intuition that the `map` function applies the function " "it is given to each element of a container, and builds a new container from " @@ -21763,7 +21841,7 @@ msgstr "" "しかし、この着想を精密にするにはどうしたらいいでしょうか。" #. type: Plain text -#: ../text/chapter6.md:305 +#: ../text/chapter6.md:343 msgid "" "Type class instances for `Functor` are expected to adhere to a set of " "_laws_, called the _functor laws_:" @@ -21772,17 +21850,17 @@ msgstr "" "待されています。" #. type: Bullet: '- ' -#: ../text/chapter6.md:308 +#: ../text/chapter6.md:346 msgid "`map identity xs = xs`" msgstr "`map identity xs = xs`" #. type: Bullet: '- ' -#: ../text/chapter6.md:308 +#: ../text/chapter6.md:346 msgid "`map g (map f xs) = map (g <<< f) xs`" msgstr "`map g (map f xs) = map (g <<< f) xs`" #. type: Plain text -#: ../text/chapter6.md:310 +#: ../text/chapter6.md:348 msgid "" "The first law is the _identity law_. It states that lifting the identity " "function (the function which returns its argument unchanged) over a " @@ -21794,7 +21872,7 @@ msgstr "" "恒等関数は入力を変更しませんから、これは理にかなっています。" #. type: Plain text -#: ../text/chapter6.md:312 +#: ../text/chapter6.md:350 msgid "" "The second law is the _composition law_. It states that mapping one function " "over a structure and then mapping a second is the same as mapping the " @@ -21805,7 +21883,7 @@ msgstr "" "のと同じだ、と言っています。" #. type: Plain text -#: ../text/chapter6.md:314 +#: ../text/chapter6.md:352 msgid "" "Whatever \"lifting\" means in the general sense, it should be true that any " "reasonable definition of lifting a function over a data structure should " @@ -21815,7 +21893,7 @@ msgstr "" "定義はこれらの法則に従っていなければなりません。" #. type: Plain text -#: ../text/chapter6.md:316 +#: ../text/chapter6.md:354 msgid "" "Many standard type classes come with their own set of similar laws. The laws " "given to a type class give structure to the functions of that type class and " @@ -21830,13 +21908,13 @@ msgstr "" "よいでしょう。" #. type: Title ### -#: ../text/chapter6.md:317 +#: ../text/chapter6.md:355 #, no-wrap msgid "Deriving Instances" msgstr "インスタンスの導出" #. type: Plain text -#: ../text/chapter6.md:320 +#: ../text/chapter6.md:358 msgid "" "Rather than writing instances manually, you can let the compiler do most of " "the work for you. Take a look at this [Type Class Deriving guide](https://" @@ -21850,18 +21928,18 @@ msgstr "" "そちらの情報が以下の演習を解く手助けになることでしょう。" #. type: Plain text -#: ../text/chapter6.md:324 +#: ../text/chapter6.md:362 msgid "The following newtype represents a complex number:" msgstr "（簡単）次のnewtypeは複素数を表します。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:325 +#: ../text/chapter6.md:363 #, no-wrap msgid "{{#include ../exercises/chapter6/test/no-peeking/Solutions.purs:Complex}}\n" msgstr "{{#include ../exercises/chapter6/test/no-peeking/Solutions.purs:Complex}}\n" #. type: Bullet: '1. ' -#: ../text/chapter6.md:330 +#: ../text/chapter6.md:368 msgid "" "(Easy) Define a `Show` instance for `Complex`. Match the output format " "expected by the tests (e.g. `1.2+3.4i`, `5.6-7.8i`, etc.)." @@ -21871,7 +21949,7 @@ msgstr "" "`5.6-7.7i`など）。" #. type: Bullet: '2. ' -#: ../text/chapter6.md:332 +#: ../text/chapter6.md:370 msgid "" "(Easy) Derive an `Eq` instance for `Complex`. _Note_: You may instead write " "this instance manually, but why do more work if you don't have to?" @@ -21881,7 +21959,7 @@ msgstr "" "になぜすることがありましょう。" #. type: Bullet: '3. ' -#: ../text/chapter6.md:334 +#: ../text/chapter6.md:372 msgid "" "(Medium) Define a `Semiring` instance for `Complex`. _Note_: You can use " "`wrap` and `over2` from [`Data.Newtype`](https://pursuit.purescript.org/" @@ -21897,7 +21975,7 @@ msgstr "" "`Newtype`インスタンスを`Complex`に導出したりする必要も出てくるでしょう。" #. type: Bullet: '4. ' -#: ../text/chapter6.md:336 +#: ../text/chapter6.md:374 msgid "" "(Easy) Derive (via `newtype`) a `Ring` instance for `Complex`. _Note_: You " "may instead write this instance manually, but that's not as convenient." @@ -21908,13 +21986,13 @@ msgstr "" "できません。" #. type: Plain text -#: ../text/chapter6.md:338 +#: ../text/chapter6.md:376 #, no-wrap msgid " Here's the `Shape` ADT from the previous chapter:\n" msgstr " 以下は前章からの`Shape`のADTです。\n" #. type: Plain text -#: ../text/chapter6.md:342 +#: ../text/chapter6.md:380 #, no-wrap msgid "" " ```haskell\n" @@ -21926,7 +22004,7 @@ msgstr "" " ```\n" #. type: Bullet: '5. ' -#: ../text/chapter6.md:344 +#: ../text/chapter6.md:382 msgid "" "(Medium) Derive (via `Generic`) a `Show` instance for `Shape`. How does the " "amount of code written and `String` output compare to `showShape` from the " @@ -21946,13 +22024,13 @@ msgstr "" "md#deriving-from-generic)節を見てください。" #. type: Title ## -#: ../text/chapter6.md:345 +#: ../text/chapter6.md:383 #, no-wrap msgid "Type Class Constraints" msgstr "型クラス制約" #. type: Plain text -#: ../text/chapter6.md:348 +#: ../text/chapter6.md:386 msgid "" "Types of functions can be constrained by using type classes. Here is an " "example: suppose we want to write a function that tests if three values are " @@ -21964,7 +22042,7 @@ msgstr "" "うかを調べる関数を書きたいとします。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:349 +#: ../text/chapter6.md:387 #, no-wrap msgid "" "threeAreEqual :: forall a. Eq a => a -> a -> a -> Boolean\n" @@ -21974,7 +22052,7 @@ msgstr "" "threeAreEqual a1 a2 a3 = a1 == a2 && a2 == a3\n" #. type: Plain text -#: ../text/chapter6.md:355 +#: ../text/chapter6.md:393 #, no-wrap msgid "The type declaration looks like an ordinary polymorphic type defined using `forall`. However, there is a type class constraint `Eq a`, separated from the rest of the type by a double arrow `=>`.\n" msgstr "" @@ -21982,7 +22060,7 @@ msgstr "" "しかし、二重線矢印 `=>`で型の残りの部分から区切られた、型クラス制約 (type class constraint) `Eq a`があります。\n" #. type: Plain text -#: ../text/chapter6.md:357 +#: ../text/chapter6.md:395 msgid "" "This type says that we can call `threeAreEqual` with any choice of type `a`, " "as long as there is an `Eq` instance available for `a` in one of the " @@ -21993,7 +22071,7 @@ msgstr "" "言っています。" #. type: Plain text -#: ../text/chapter6.md:359 +#: ../text/chapter6.md:397 msgid "" "Constrained types can contain several type class instances, and the types of " "the instances are not restricted to simple type variables. Here is another " @@ -22004,7 +22082,7 @@ msgstr "" "2つの値を比較する例を次に示します。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:360 +#: ../text/chapter6.md:398 #, no-wrap msgid "" "showCompare :: forall a. Ord a => Show a => a -> a -> String\n" @@ -22024,7 +22102,7 @@ msgstr "" " show a1 <> \" is equal to \" <> show a2\n" #. type: Plain text -#: ../text/chapter6.md:372 +#: ../text/chapter6.md:410 #, no-wrap msgid "" "Note that multiple constraints can be specified by using the `=>` symbol multiple times, just like we specify curried functions\n" @@ -22036,19 +22114,19 @@ msgstr "" # whereasは次の項目に移します #. type: Bullet: '- ' -#: ../text/chapter6.md:375 +#: ../text/chapter6.md:413 msgid "" "`a -> b` denotes the type of functions from _type_ `a` to _type_ `b`, whereas" msgstr "`a -> b`は _型_ `a`から _型_ `b`への関数の型を表します。" # 「一方で」は前の項目から来ています #. type: Bullet: '- ' -#: ../text/chapter6.md:375 +#: ../text/chapter6.md:413 msgid "`a => b` applies the _constraint_ `a` to the type `b`." msgstr "一方で、`a => b`は _制約_ `a`を型`b`に適用します。" #. type: Plain text -#: ../text/chapter6.md:377 +#: ../text/chapter6.md:415 msgid "" "The PureScript compiler will try to infer constrained types when a type " "annotation is not provided. This can be useful if we want to use the most " @@ -22059,7 +22137,7 @@ msgstr "" "便利です。" #. type: Plain text -#: ../text/chapter6.md:379 +#: ../text/chapter6.md:417 msgid "" "To see this, try using one of the standard type classes like `Semiring` in " "PSCi:" @@ -22068,7 +22146,7 @@ msgstr "" "しょう。" #. type: Fenced code block (text) -#: ../text/chapter6.md:380 +#: ../text/chapter6.md:418 #, no-wrap msgid "" "> import Prelude\n" @@ -22082,7 +22160,7 @@ msgstr "" "forall (a :: Type). Semiring a => a -> a\n" #. type: Plain text -#: ../text/chapter6.md:388 +#: ../text/chapter6.md:426 #, no-wrap msgid "Here, we might have annotated this function as `Int -> Int` or `Number -> Number`, but PSCi shows us that the most general type works for any `Semiring`, allowing us to use our function with both `Int`s and `Number.\n" msgstr "" @@ -22091,13 +22169,13 @@ msgstr "" "こうすると`Int`と`Number`の両方で関数を使えます。\n" #. type: Title ## -#: ../text/chapter6.md:389 +#: ../text/chapter6.md:427 #, no-wrap msgid "Instance Dependencies" msgstr "インスタンスの依存関係" #. type: Plain text -#: ../text/chapter6.md:392 +#: ../text/chapter6.md:430 msgid "" "Just as the implementation of functions can depend on type class instances " "using constrained types, so can the implementation of type class instances " @@ -22111,7 +22189,7 @@ msgstr "" "します。" #. type: Plain text -#: ../text/chapter6.md:394 +#: ../text/chapter6.md:432 msgid "" "For example, consider the `Show` type class. We can write a type class " "instance to `show` arrays of elements, as long as we have a way to `show` " @@ -22122,7 +22200,7 @@ msgstr "" "スインスタンスを書くことができます。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:395 +#: ../text/chapter6.md:433 #, no-wrap msgid "" "instance Show a => Show (Array a) where\n" @@ -22132,13 +22210,13 @@ msgstr "" " ...\n" #. type: Plain text -#: ../text/chapter6.md:401 +#: ../text/chapter6.md:439 #, no-wrap msgid "If a type class instance depends on multiple other instances, those instances should be grouped in parentheses and separated by commas on the left-hand side of the `=>` symbol:\n" msgstr "型クラスインスタンスが複数の他のインスタンスに依存する場合、括弧で囲んでそれらのインスタンスをコンマで区切り、それを`=>`シンボルの左側に置くことになります。\n" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:402 +#: ../text/chapter6.md:440 #, no-wrap msgid "" "instance (Show a, Show b) => Show (Either a b) where\n" @@ -22148,12 +22226,12 @@ msgstr "" " ...\n" #. type: Plain text -#: ../text/chapter6.md:408 +#: ../text/chapter6.md:446 msgid "These two type class instances are provided in the `prelude` library." msgstr "これらの2つの型クラスインスタンスは `prelude`ライブラリにあります。" #. type: Plain text -#: ../text/chapter6.md:410 +#: ../text/chapter6.md:448 msgid "" "When the program is compiled, the correct type class instance for `Show` is " "chosen based on the inferred type of the argument to `show`. The selected " @@ -22166,14 +22244,14 @@ msgstr "" "れませんが、このあたりの複雑さに開発者が関与することはありません。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:414 +#: ../text/chapter6.md:452 msgid "" "(Easy) The following declaration defines a type of non-empty arrays of " "elements of type `a`:" msgstr "（簡単）以下の宣言では型 `a`の要素の空でない配列の型を定義しています。" #. type: Plain text -#: ../text/chapter6.md:418 +#: ../text/chapter6.md:456 #, no-wrap msgid "" " ```haskell\n" @@ -22185,7 +22263,7 @@ msgstr "" " ```\n" #. type: Plain text -#: ../text/chapter6.md:420 +#: ../text/chapter6.md:458 #, no-wrap msgid " Write an `Eq` instance for the type `NonEmpty a` that reuses the instances for `Eq a` and `Eq (Array a)`. _Note:_ you may instead derive the `Eq` instance.\n" msgstr "" @@ -22193,7 +22271,7 @@ msgstr "" " *補足*：代わりに`Eq`インスタンスを導出できます。\n" #. type: Bullet: '1. ' -#: ../text/chapter6.md:422 +#: ../text/chapter6.md:460 msgid "" "(Medium) Write a `Semigroup` instance for `NonEmpty a` by reusing the " "`Semigroup` instance for `Array`." @@ -22202,12 +22280,12 @@ msgstr "" "`Semigroup`インスタンスを書いてください。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:424 +#: ../text/chapter6.md:462 msgid "(Medium) Write a `Functor` instance for `NonEmpty`." msgstr "（普通）`NonEmpty`に`Functor`インスタンスを書いてください。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:426 +#: ../text/chapter6.md:464 msgid "" "(Medium) Given any type `a` with an instance of `Ord`, we can add a new " "\"infinite\" value that is greater than any other value:" @@ -22216,7 +22294,7 @@ msgstr "" "それ以外のどんな値よりも大きい「無限の」値を付け加えられます。" #. type: Plain text -#: ../text/chapter6.md:430 +#: ../text/chapter6.md:468 #, no-wrap msgid "" " ```haskell\n" @@ -22228,13 +22306,13 @@ msgstr "" " ```\n" #. type: Plain text -#: ../text/chapter6.md:432 +#: ../text/chapter6.md:470 #, no-wrap msgid " Write an `Ord` instance for `Extended a` that reuses the `Ord` instance for `a`.\n" msgstr " `a`への`Ord`インスタンスを再利用して、`Extended a`に`Ord`インスタンスを書いてください。\n" #. type: Bullet: '1. ' -#: ../text/chapter6.md:434 +#: ../text/chapter6.md:472 msgid "" "(Difficult) Write a `Foldable` instance for `NonEmpty`. _Hint_: reuse the " "`Foldable` instance for arrays." @@ -22243,7 +22321,7 @@ msgstr "" "*手掛かり*：配列への`Foldable`インスタンスを再利用してください。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:436 +#: ../text/chapter6.md:474 msgid "" "(Difficult) Given a type constructor `f` which defines an ordered container " "(and so has a `Foldable` instance), we can create a new container type that " @@ -22254,7 +22332,7 @@ msgstr "" "テナ型を作れます。" #. type: Plain text -#: ../text/chapter6.md:440 +#: ../text/chapter6.md:478 #, no-wrap msgid "" " ```haskell\n" @@ -22266,7 +22344,7 @@ msgstr "" " ```\n" #. type: Plain text -#: ../text/chapter6.md:442 +#: ../text/chapter6.md:480 #, no-wrap msgid " The container `OneMore f` also has an ordering, where the new element comes before any element of `f`. Write a `Foldable` instance for `OneMore f`:\n" msgstr "" @@ -22275,7 +22353,7 @@ msgstr "" " この `OneMore f`の `Foldable`インスタンスを書いてみましょう。\n" #. type: Plain text -#: ../text/chapter6.md:447 +#: ../text/chapter6.md:485 #, no-wrap msgid "" " ```haskell\n" @@ -22289,7 +22367,7 @@ msgstr "" " ```\n" #. type: Bullet: '1. ' -#: ../text/chapter6.md:449 +#: ../text/chapter6.md:487 msgid "" "(Medium) Write a `dedupShapes :: Array Shape -> Array Shape` function that " "removes duplicate `Shape`s from an array using the `nubEq` function." @@ -22298,7 +22376,7 @@ msgstr "" "Array Shape -> Array Shape`関数を書いてください。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:451 +#: ../text/chapter6.md:489 msgid "" "(Medium) Write a `dedupShapesFast` function which is the same as " "`dedupShapes`, but uses the more efficient `nub` function." @@ -22307,13 +22385,13 @@ msgstr "" "`dedupShapes`とほぼ同じですが、より効率の良い`nub`関数を使います。" #. type: Title ## -#: ../text/chapter6.md:452 +#: ../text/chapter6.md:490 #, no-wrap msgid "Multi-Parameter Type Classes" msgstr "多変数型クラス" #. type: Plain text -#: ../text/chapter6.md:455 +#: ../text/chapter6.md:493 msgid "" "It's not the case that a type class can only take a single type as an " "argument. This is the most common case, but a type class can be " @@ -22323,12 +22401,12 @@ msgstr "" "その場合がほとんどですが、型クラスは*ゼロ個以上の*型変数を持てます。" #. type: Plain text -#: ../text/chapter6.md:457 +#: ../text/chapter6.md:495 msgid "Let's see an example of a type class with two type arguments." msgstr "それでは2つの型引数を持つ型クラスの例を見てみましょう。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:458 +#: ../text/chapter6.md:496 #, no-wrap msgid "" "module Stream where\n" @@ -22362,7 +22440,7 @@ msgstr "" " uncons = String.uncons\n" #. type: Plain text -#: ../text/chapter6.md:476 +#: ../text/chapter6.md:514 msgid "" "The `Stream` module defines a class `Stream` which identifies types that " "look like streams of elements, where elements can be pulled from the front " @@ -22373,7 +22451,7 @@ msgstr "" "`uncons`関数を使ってストリームの先頭から要素を取り出すことができます。" #. type: Plain text -#: ../text/chapter6.md:478 +#: ../text/chapter6.md:516 msgid "" "Note that the `Stream` type class is parameterized not only by the type of " "the stream itself, but also by its elements. This allows us to define type " @@ -22384,7 +22462,7 @@ msgstr "" "の型について異なる型クラスインスタンスを定義できます。" #. type: Plain text -#: ../text/chapter6.md:480 +#: ../text/chapter6.md:518 msgid "" "The module defines two type class instances: an instance for arrays, where " "`uncons` removes the head element of the array using pattern matching, and " @@ -22395,7 +22473,7 @@ msgstr "" "と、文字列から最初の文字を取り除くような文字列のインスタンスです。" #. type: Plain text -#: ../text/chapter6.md:482 +#: ../text/chapter6.md:520 msgid "" "We can write functions that work over arbitrary streams. For example, here " "is a function that accumulates a result in some `Monoid` based on the " @@ -22406,7 +22484,7 @@ msgstr "" "ります。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:483 +#: ../text/chapter6.md:521 #, no-wrap msgid "" "import Prelude\n" @@ -22428,7 +22506,7 @@ msgstr "" " Just cons -> f cons.head <> foldStream f cons.tail\n" #. type: Plain text -#: ../text/chapter6.md:495 +#: ../text/chapter6.md:533 msgid "" "Try using `foldStream` in PSCi for different types of `Stream` and different " "types of `Monoid`." @@ -22437,13 +22515,13 @@ msgstr "" "呼び出してみましょう。" #. type: Title ## -#: ../text/chapter6.md:496 +#: ../text/chapter6.md:534 #, no-wrap msgid "Functional Dependencies" msgstr "関数従属性" #. type: Plain text -#: ../text/chapter6.md:499 +#: ../text/chapter6.md:537 msgid "" "Multi-parameter type classes can be very useful but can easily lead to " "confusing types and even issues with type inference. As a simple example, " @@ -22456,18 +22534,18 @@ msgstr "" "的な`tail`関数を書くことを考えてみましょう。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:500 +#: ../text/chapter6.md:538 #, no-wrap msgid "genericTail xs = map _.tail (uncons xs)\n" msgstr "genericTail xs = map _.tail (uncons xs)\n" #. type: Plain text -#: ../text/chapter6.md:505 +#: ../text/chapter6.md:543 msgid "This gives a somewhat confusing error message:" msgstr "これはやや複雑なエラー文言を出力します。" #. type: Fenced code block (text) -#: ../text/chapter6.md:506 +#: ../text/chapter6.md:544 #, no-wrap msgid "" "The inferred type\n" @@ -22483,7 +22561,7 @@ msgstr "" "has type variables which are not mentioned in the body of the type. Consider adding a type annotation.\n" #. type: Plain text -#: ../text/chapter6.md:515 +#: ../text/chapter6.md:553 msgid "" "The problem is that the `genericTail` function does not use the `element` " "type mentioned in the definition of the `Stream` type class, so that type is " @@ -22493,7 +22571,7 @@ msgstr "" "を使用しないので、その型は未解決のままであることを指しています。" #. type: Plain text -#: ../text/chapter6.md:517 +#: ../text/chapter6.md:555 msgid "" "Worse still, we cannot even use `genericTail` by applying it to a specific " "type of stream:" @@ -22501,7 +22579,7 @@ msgstr "" "更に残念なことに、特定の型のストリームに`genericTail`を適用できません。" #. type: Fenced code block (text) -#: ../text/chapter6.md:518 +#: ../text/chapter6.md:556 #, no-wrap msgid "" "> map _.tail (uncons \"testing\")\n" @@ -22521,7 +22599,7 @@ msgstr "" "has type variables which are not mentioned in the body of the type. Consider adding a type annotation.\n" #. type: Plain text -#: ../text/chapter6.md:529 +#: ../text/chapter6.md:567 msgid "" "Here, we might expect the compiler to choose the `streamString` instance. " "After all, a `String` is a stream of `Char`s, and cannot be a stream of any " @@ -22533,7 +22611,7 @@ msgstr "" "てはなりません。" #. type: Plain text -#: ../text/chapter6.md:531 +#: ../text/chapter6.md:569 msgid "" "The compiler cannot make that deduction automatically or commit to the " "`streamString` instance. However, we can help the compiler by adding a hint " @@ -22544,7 +22622,7 @@ msgstr "" "しかし、型クラス定義に手掛かりを追加すると、コンパイラを補助できます。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:532 +#: ../text/chapter6.md:570 #, no-wrap msgid "" "class Stream stream element | stream -> element where\n" @@ -22554,13 +22632,13 @@ msgstr "" " uncons :: stream -> Maybe { head :: element, tail :: stream }\n" #. type: Plain text -#: ../text/chapter6.md:538 +#: ../text/chapter6.md:576 #, no-wrap msgid "Here, `stream -> element` is called a _functional dependency_. A functional dependency asserts a functional relationship between the type arguments of a multi-parameter type class. This functional dependency tells the compiler that there is a function from stream types to (unique) element types, so if the compiler knows the stream type, then it can commit to the element type.\n" msgstr "ここで、 `stream -> element`は _関数従属性_ (functional dependency) と呼ばれます。関数従属性は、多変数型クラスの型引数間の関数関係を宣言します。この関数の依存関係は、ストリーム型から（一意の）要素型への関数があることをコンパイラに伝えるので、コンパイラがストリーム型を知っていれば要素の型を割り当てられます。\n" #. type: Plain text -#: ../text/chapter6.md:540 +#: ../text/chapter6.md:578 msgid "" "This hint is enough for the compiler to infer the correct type for our " "generic tail function above:" @@ -22569,7 +22647,7 @@ msgstr "" "のに充分です。" #. type: Fenced code block (text) -#: ../text/chapter6.md:541 +#: ../text/chapter6.md:579 #, no-wrap msgid "" "> :type genericTail\n" @@ -22585,7 +22663,7 @@ msgstr "" "(Just \"esting\")\n" #. type: Plain text -#: ../text/chapter6.md:550 +#: ../text/chapter6.md:588 msgid "" "Functional dependencies can be useful when designing certain APIs using " "multi-parameter type classes." @@ -22594,13 +22672,13 @@ msgstr "" "あります。" #. type: Title ## -#: ../text/chapter6.md:551 +#: ../text/chapter6.md:589 #, no-wrap msgid "Nullary Type Classes" msgstr "型変数のない型クラス" #. type: Plain text -#: ../text/chapter6.md:554 +#: ../text/chapter6.md:592 msgid "" "We can even define type classes with zero-type arguments! These correspond " "to compile-time assertions about our functions, allowing us to track the " @@ -22611,7 +22689,7 @@ msgstr "" "のコードの大域的な性質を把握できます。" #. type: Plain text -#: ../text/chapter6.md:556 +#: ../text/chapter6.md:594 msgid "" "An important example is the `Partial` class we saw earlier when discussing " "partial functions. Take, for example, the functions `head` and `tail` " @@ -22626,7 +22704,7 @@ msgstr "" "そのため配列が空のときに失敗する可能性があります。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:557 +#: ../text/chapter6.md:595 #, no-wrap msgid "" "head :: forall a. Partial => Array a -> a\n" @@ -22638,7 +22716,7 @@ msgstr "" "tail :: forall a. Partial => Array a -> Array a\n" #. type: Plain text -#: ../text/chapter6.md:564 +#: ../text/chapter6.md:602 msgid "" "Note that there is no instance defined for the `Partial` type class! Doing " "so would defeat its purpose: attempting to use the `head` function directly " @@ -22650,7 +22728,7 @@ msgstr "" "このままの定義では `head`関数を使用しようとすると型エラーになるのです。" #. type: Fenced code block (text) -#: ../text/chapter6.md:565 +#: ../text/chapter6.md:603 #, no-wrap msgid "" "> head [1, 2, 3]\n" @@ -22666,7 +22744,7 @@ msgstr "" " Prim.Partial\n" #. type: Plain text -#: ../text/chapter6.md:574 +#: ../text/chapter6.md:612 msgid "" "Instead, we can republish the `Partial` constraint for any functions making " "use of partial functions:" @@ -22675,7 +22753,7 @@ msgstr "" "す。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:575 +#: ../text/chapter6.md:613 #, no-wrap msgid "" "secondElement :: forall a. Partial => Array a -> a\n" @@ -22685,7 +22763,7 @@ msgstr "" "secondElement xs = head (tail xs)\n" #. type: Plain text -#: ../text/chapter6.md:581 +#: ../text/chapter6.md:619 msgid "" "We've already seen the `unsafePartial` function, which allows us to treat a " "partial function as a regular function (unsafely). This function is defined " @@ -22695,13 +22773,13 @@ msgstr "" "扱うことができます。この関数は `Partial.Unsafe`モジュールで定義されています。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:582 +#: ../text/chapter6.md:620 #, no-wrap msgid "unsafePartial :: forall a. (Partial => a) -> a\n" msgstr "unsafePartial :: forall a. (Partial => a) -> a\n" #. type: Plain text -#: ../text/chapter6.md:587 +#: ../text/chapter6.md:625 msgid "" "Note that the `Partial` constraint appears _inside the parentheses_ on the " "left of the function arrow, but not in the outer `forall`. That is, " @@ -22712,7 +22790,7 @@ msgstr "" "つまり、 `unsafePartial`は部分的な値から通常の値への関数です。" #. type: Fenced code block (text) -#: ../text/chapter6.md:588 +#: ../text/chapter6.md:626 #, no-wrap msgid "" "> unsafePartial head [1, 2, 3]\n" @@ -22728,13 +22806,13 @@ msgstr "" "2\n" #. type: Title ## -#: ../text/chapter6.md:596 +#: ../text/chapter6.md:634 #, no-wrap msgid "Superclasses" msgstr "上位クラス" #. type: Plain text -#: ../text/chapter6.md:599 +#: ../text/chapter6.md:637 msgid "" "Just as we can express relationships between type class instances by making " "an instance dependent on another instance, we can express relationships " @@ -22745,7 +22823,7 @@ msgstr "" "現できます。" #. type: Plain text -#: ../text/chapter6.md:601 +#: ../text/chapter6.md:639 #, no-wrap msgid "We say that one type class is a superclass of another if every instance of the second class is required to be an instance of the first, and we indicate a superclass relationship in the class definition by using a backwards facing double arrow ( `<=` ).\n" msgstr "" @@ -22753,7 +22831,7 @@ msgstr "" "そしてクラス定義で逆向きの太い矢印 (`<=`) を使って上位クラス関係を示します。\n" #. type: Plain text -#: ../text/chapter6.md:603 +#: ../text/chapter6.md:641 msgid "" "We've [already seen an example of superclass relationships](#ord): the `Eq` " "class is a superclass of `Ord`, and the `Semigroup` class is a superclass of " @@ -22773,28 +22851,23 @@ msgstr "" "あるかを判定するために`Eq`クラスを使うことでしょう。" #. type: Plain text -#: ../text/chapter6.md:605 +#: ../text/chapter6.md:643 msgid "" "In general, it makes sense to define a superclass relationship when the laws " "for the subclass mention the superclass members. For example, for any pair " -"of Ord and Eq instances, it is reasonable to assume that if two values are " -"equal under the `Eq` instance, then the `compare` function should return " +"of `Ord` and `Eq` instances, it is reasonable to assume that if two values " +"are equal under the `Eq` instance, then the `compare` function should return " "`EQ`. In other words, `a == b` should be true exactly when `compare a b` " "evaluates to `EQ`. This relationship on the level of laws justifies the " "superclass relationship between `Eq` and `Ord`." msgstr "" -"一般に、下位クラスの法則が上位クラスの構成要素に言及しているとき、上位クラス" -"関係を定義するのは筋が通っています。\n" -"例えば、任意の`Ord`と`Eq`のインスタンスの対について、もし2つの値が`Eq`インス" -"タンスの下で同値であるなら、`compare`関数は`EQ`を返すはずだと推定するのは理に" -"適っています。\n" -"言い換えれば、`a == b`が真であるのは`compare a b`が厳密に`EQ`に評価されるとき" -"なのです。\n" -"法則のレベルでのこの関係は、`Eq`と`Ord`の間の上位クラス関係の正当性を示しま" -"す。" +"一般に、下位クラスの法則が上位クラスの構成要素に言及しているとき、上位クラス関係を定義するのは筋が通っています。\n" +"例えば、任意の`Ord`と`Eq`のインスタンスの対について、もし2つの値が`Eq`インスタンスの下で同値であるなら、`compare`関数は`EQ`を返すはずだと推定するのは理に適っています。\n" +"言い換えれば、`a == b`が真であるのは`compare a b`が厳密に`EQ`に評価されるときなのです。\n" +"法則のレベルでのこの関係は、`Eq`と`Ord`の間の上位クラス関係の正当性を示します。" #. type: Plain text -#: ../text/chapter6.md:607 +#: ../text/chapter6.md:645 msgid "" "Another reason to define a superclass relationship is when there is a clear " "\"is-a\" relationship between the two classes. That is, every member of the " @@ -22805,7 +22878,7 @@ msgstr "" "下位クラスの全ての構成要素は、上位クラスの構成要素でもあるということです。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:611 +#: ../text/chapter6.md:649 msgid "" "(Medium) Define a partial function `unsafeMaximum :: Partial => Array Int -> " "Int` that finds the maximum of a non-empty array of integers. Test out your " @@ -22819,7 +22892,7 @@ msgstr "" "*手掛かり*：`Data.Foldable`の`maximum`関数を使います。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:613 +#: ../text/chapter6.md:651 msgid "" "(Medium) The `Action` class is a multi-parameter type class that defines an " "action of one type on another:" @@ -22828,7 +22901,7 @@ msgstr "" "スです。" #. type: Plain text -#: ../text/chapter6.md:617 +#: ../text/chapter6.md:655 #, no-wrap msgid "" " ```haskell\n" @@ -22840,7 +22913,7 @@ msgstr "" " ```\n" #. type: Plain text -#: ../text/chapter6.md:619 +#: ../text/chapter6.md:657 #, no-wrap msgid " An _action_ is a function that describes how monoidal values are used to determine how to modify a value of another type. There are two laws for the `Action` type class:\n" msgstr "" @@ -22848,17 +22921,17 @@ msgstr "" " `Action`型クラスには2つの法則があります。\n" #. type: Bullet: ' - ' -#: ../text/chapter6.md:622 +#: ../text/chapter6.md:660 msgid "`act mempty a = a`" msgstr "`act mempty a = a`" #. type: Bullet: ' - ' -#: ../text/chapter6.md:622 +#: ../text/chapter6.md:660 msgid "`act (m1 <> m2) a = act m1 (act m2 a)`" msgstr "`act (m1 <> m2) a = act m1 (act m2 a)`" #. type: Plain text -#: ../text/chapter6.md:624 +#: ../text/chapter6.md:662 #, no-wrap msgid " Applying an empty action is a no-op. And applying two actions in sequence is the same as applying the actions combined. That is, actions respect the operations defined by the `Monoid` class.\n" msgstr "" @@ -22867,13 +22940,13 @@ msgstr "" " つまり、動作は`Monoid`クラスで定義される操作に倣っています。\n" #. type: Plain text -#: ../text/chapter6.md:626 +#: ../text/chapter6.md:664 #, no-wrap msgid " For example, the natural numbers form a monoid under multiplication:\n" msgstr " 例えば自然数は乗算のもとでモノイドを形成します。\n" #. type: Plain text -#: ../text/chapter6.md:629 +#: ../text/chapter6.md:667 #, no-wrap msgid "" " ```haskell\n" @@ -22883,13 +22956,13 @@ msgstr "" " {{#include ../exercises/chapter6/test/no-peeking/Solutions.purs:Multiply}}\n" #. type: Plain text -#: ../text/chapter6.md:631 +#: ../text/chapter6.md:669 #, no-wrap msgid " {{#include ../exercises/chapter6/test/no-peeking/Solutions.purs:semigroupMultiply}}\n" msgstr " {{#include ../exercises/chapter6/test/no-peeking/Solutions.purs:semigroupMultiply}}\n" #. type: Plain text -#: ../text/chapter6.md:634 +#: ../text/chapter6.md:672 #, no-wrap msgid "" " {{#include ../exercises/chapter6/test/no-peeking/Solutions.purs:monoidMultiply}}\n" @@ -22899,13 +22972,13 @@ msgstr "" " ```\n" #. type: Plain text -#: ../text/chapter6.md:636 +#: ../text/chapter6.md:674 #, no-wrap msgid " Write an instance that implements this action:\n" msgstr " この動作を実装するインスタンスを書いてください。\n" #. type: Plain text -#: ../text/chapter6.md:641 +#: ../text/chapter6.md:679 #, no-wrap msgid "" " ```haskell\n" @@ -22919,13 +22992,13 @@ msgstr "" " ```\n" #. type: Plain text -#: ../text/chapter6.md:643 +#: ../text/chapter6.md:681 #, no-wrap msgid " Remember, your instance must satisfy the laws listed above.\n" msgstr " インスタンスが上で挙げた法則を見たさなくてはならないことを思い出してください。\n" #. type: Bullet: '1. ' -#: ../text/chapter6.md:645 +#: ../text/chapter6.md:683 msgid "" "(Difficult) There are multiple ways to implement an instance of `Action " "Multiply Int`. How many can you think of? PureScript does not allow multiple " @@ -22940,7 +23013,7 @@ msgstr "" "*補足*：テストでは4つの実装を押さえています。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:647 +#: ../text/chapter6.md:685 msgid "" "(Medium) Write an `Action` instance that repeats an input string some number " "of times:" @@ -22948,7 +23021,7 @@ msgstr "" "（普通）入力の文字列を何回か繰り返す`Action`インスタンスを書いてください。" #. type: Plain text -#: ../text/chapter6.md:652 +#: ../text/chapter6.md:690 #, no-wrap msgid "" " ```haskell\n" @@ -22962,7 +23035,7 @@ msgstr "" " ```\n" #. type: Plain text -#: ../text/chapter6.md:654 +#: ../text/chapter6.md:692 #, no-wrap msgid " _Hint_: Search Pursuit for a helper-function with the signature [`String -> Int -> String`](https://pursuit.purescript.org/search?q=String%20-%3E%20Int%20-%3E%20String). Note that `String` might appear as a more generic type (such as `Monoid`).\n" msgstr "" @@ -22970,13 +23043,13 @@ msgstr "" " なお、`String`は（`Monoid`のような）より汎用的な型として現れます。\n" #. type: Plain text -#: ../text/chapter6.md:656 +#: ../text/chapter6.md:694 #, no-wrap msgid " Does this instance satisfy the laws listed above?\n" msgstr " このインスタンスは上に挙げた法則を満たすでしょうか。\n" #. type: Bullet: '1. ' -#: ../text/chapter6.md:658 +#: ../text/chapter6.md:696 msgid "" "(Medium) Write an instance `Action m a => Action m (Array a)`, where the " "action on arrays is defined by acting on each array element independently." @@ -22985,7 +23058,7 @@ msgstr "" "ここで、 配列上の動作はそれぞれの要素を独立に実行するものとして定義されます。" #. type: Bullet: '1. ' -#: ../text/chapter6.md:660 +#: ../text/chapter6.md:698 msgid "" "(Difficult) Given the following newtype, write an instance for `Action m " "(Self m)`, where the monoid `m` acts on itself using `append`:" @@ -22995,7 +23068,7 @@ msgstr "" "ここでモノイド`m`はそれ自体が持つ`append`を用いて動作します。" #. type: Plain text -#: ../text/chapter6.md:664 +#: ../text/chapter6.md:702 #, no-wrap msgid "" " ```haskell\n" @@ -23007,7 +23080,7 @@ msgstr "" " ```\n" #. type: Plain text -#: ../text/chapter6.md:666 +#: ../text/chapter6.md:704 #, no-wrap msgid " _Note_: The testing framework requires `Show` and `Eq` instances for the `Self` and `Multiply` types. You may either write these instances manually, or let the compiler handle this for you with [`derive newtype instance`](https://github.com/purescript/documentation/blob/master/language/Type-Classes.md#derive-from-newtype) shorthand.\n" msgstr "" @@ -23015,7 +23088,7 @@ msgstr "" " 手作業でこれらのインスタンスを書いてもよいですし、[`derive newtype instance`](https://github.com/purescript/documentation/blob/master/language/Type-Classes.md#derive-from-newtype)と書くだけでコンパイラに取り仕切ってもらうこともできます。\n" #. type: Bullet: '1. ' -#: ../text/chapter6.md:668 +#: ../text/chapter6.md:706 msgid "" "(Difficult) Should the arguments of the multi-parameter type class `Action` " "be related by some functional dependency? Why or why not? _Note_: There is " @@ -23027,13 +23100,13 @@ msgstr "" "*補足*：この演習にはテストがありません。" #. type: Title ## -#: ../text/chapter6.md:669 +#: ../text/chapter6.md:707 #, no-wrap msgid "A Type Class for Hashes" msgstr "ハッシュの型クラス" #. type: Plain text -#: ../text/chapter6.md:672 +#: ../text/chapter6.md:710 msgid "" "In the last section of this chapter, we will use the lessons from the rest " "of the chapter to create a library for hashing data structures." @@ -23042,18 +23115,18 @@ msgstr "" "ます。" #. type: Plain text -#: ../text/chapter6.md:674 +#: ../text/chapter6.md:712 #, no-wrap msgid "> Note that this library is for demonstration purposes only and is not intended to provide a robust hashing mechanism.\n" msgstr "> なお、このライブラリは説明だけを目的としており、堅牢なハッシュ化の仕組みの提供は意図していません。\n" #. type: Plain text -#: ../text/chapter6.md:676 +#: ../text/chapter6.md:714 msgid "What properties might we expect of a hash function?" msgstr "ハッシュ関数に期待される性質とはどのようなものでしょうか。" #. type: Bullet: '- ' -#: ../text/chapter6.md:679 +#: ../text/chapter6.md:717 msgid "" "A hash function should be deterministic and map equal values to equal hash " "codes." @@ -23062,7 +23135,7 @@ msgstr "" "つまり、同じ値は同じハッシュコードに写さなければなりません。" #. type: Bullet: '- ' -#: ../text/chapter6.md:679 +#: ../text/chapter6.md:717 msgid "" "A hash function should distribute its results approximately uniformly over " "some set of hash codes." @@ -23071,7 +23144,7 @@ msgstr "" "ん。" #. type: Plain text -#: ../text/chapter6.md:681 +#: ../text/chapter6.md:719 msgid "" "The first property looks a lot like a law for a type class, whereas the " "second property is more along the lines of an informal contract and " @@ -23084,20 +23157,20 @@ msgstr "" "しかし、これは型クラスから次のような直感が得られるでしょう。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:682 +#: ../text/chapter6.md:720 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:Hashable}}\n" msgstr "{{#include ../exercises/chapter6/src/Data/Hashable.purs:Hashable}}\n" #. type: Plain text -#: ../text/chapter6.md:687 +#: ../text/chapter6.md:725 msgid "with the associated law that `a == b` implies `hash a == hash b`." msgstr "" "これに、 `a == b`ならば `hash a == hash b`を示唆するという関係性の法則が付随" "しています。" #. type: Plain text -#: ../text/chapter6.md:689 +#: ../text/chapter6.md:727 msgid "" "We'll spend the rest of this section building a library of instances and " "functions associated with the `Hashable` type class." @@ -23106,18 +23179,18 @@ msgstr "" "ンスと関数のライブラリを構築していきます。" #. type: Plain text -#: ../text/chapter6.md:691 +#: ../text/chapter6.md:729 msgid "We will need a way to combine hash codes in a deterministic way:" msgstr "決定的な方法でハッシュ値を結合する方法が必要になります。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:692 +#: ../text/chapter6.md:730 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:combineHashes}}\n" msgstr "{{#include ../exercises/chapter6/src/Data/Hashable.purs:combineHashes}}\n" #. type: Plain text -#: ../text/chapter6.md:697 +#: ../text/chapter6.md:735 msgid "" "The `combineHashes` function will mix two hash codes and redistribute the " "result over the interval 0-65535." @@ -23125,7 +23198,7 @@ msgstr "" "`combineHashes`関数は2つのハッシュ値を混ぜて結果を0-65535の間に分布します。" #. type: Plain text -#: ../text/chapter6.md:699 +#: ../text/chapter6.md:737 msgid "" "Let's write a function that uses the `Hashable` constraint to restrict the " "types of its inputs. One common task which requires a hashing function is to " @@ -23139,13 +23212,13 @@ msgstr "" "`hashEqual`関係はそのような機能を提供します。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:700 +#: ../text/chapter6.md:738 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashEqual}}\n" msgstr "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashEqual}}\n" #. type: Plain text -#: ../text/chapter6.md:705 +#: ../text/chapter6.md:743 msgid "" "This function uses the `on` function from `Data.Function` to define hash-" "equality in terms of equality of hash codes, and should read like a " @@ -23159,7 +23232,7 @@ msgstr "" "の値は「ハッシュ同値」です。" #. type: Plain text -#: ../text/chapter6.md:707 +#: ../text/chapter6.md:745 msgid "" "Let's write some `Hashable` instances for some primitive types. Let's start " "with an instance for integers. Since a `HashCode` is really just a wrapped " @@ -23171,26 +23244,26 @@ msgstr "" "`hashCode`補助関数を使えます。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:708 +#: ../text/chapter6.md:746 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashInt}}\n" msgstr "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashInt}}\n" #. type: Plain text -#: ../text/chapter6.md:713 +#: ../text/chapter6.md:751 msgid "" "We can also define a simple instance for `Boolean` values using pattern " "matching:" msgstr "パターン照合を使うと、`Boolean`値の単純なインスタンスも定義できます。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:714 +#: ../text/chapter6.md:752 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashBoolean}}\n" msgstr "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashBoolean}}\n" #. type: Plain text -#: ../text/chapter6.md:719 +#: ../text/chapter6.md:757 msgid "" "With an instance for hashing integers, we can create an instance for hashing " "`Char`s by using the `toCharCode` function from `Data.Char`:" @@ -23199,13 +23272,13 @@ msgstr "" "シュ化するインスタンスを作成できます。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:720 +#: ../text/chapter6.md:758 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashChar}}\n" msgstr "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashChar}}\n" #. type: Plain text -#: ../text/chapter6.md:725 +#: ../text/chapter6.md:763 msgid "" "To define an instance for arrays, we can `map` the `hash` function over the " "elements of the array (if the element type is also an instance of " @@ -23217,13 +23290,13 @@ msgstr "" "で、配列のインスタンスを定義します。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:726 +#: ../text/chapter6.md:764 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashArray}}\n" msgstr "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashArray}}\n" #. type: Plain text -#: ../text/chapter6.md:731 +#: ../text/chapter6.md:769 msgid "" "Notice how we build up instances using the simpler instances we have already " "written. Let's use our new `Array` instance to define an instance for " @@ -23235,13 +23308,13 @@ msgstr "" "のインスタンスを定義しましょう。" #. type: Fenced code block (haskell) -#: ../text/chapter6.md:732 +#: ../text/chapter6.md:770 #, no-wrap msgid "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashString}}\n" msgstr "{{#include ../exercises/chapter6/src/Data/Hashable.purs:hashString}}\n" #. type: Plain text -#: ../text/chapter6.md:737 +#: ../text/chapter6.md:775 msgid "" "How can we prove that these `Hashable` instances satisfy the type class law " "that we stated above? We need to make sure that equal values have equal hash " @@ -23257,7 +23330,7 @@ msgstr "" "からです。" #. type: Plain text -#: ../text/chapter6.md:739 +#: ../text/chapter6.md:777 msgid "" "What about some more interesting types? To prove the type class law for the " "`Array` instance, we can use induction on the length of the array. The only " @@ -23281,7 +23354,7 @@ msgstr "" "ラス法則に従います。" #. type: Plain text -#: ../text/chapter6.md:741 +#: ../text/chapter6.md:779 msgid "" "The source code for this chapter includes several other examples of " "`Hashable` instances, such as instances for the `Maybe` and `Tuple` type." @@ -23290,7 +23363,7 @@ msgstr "" "`Hashable`インスタンスの例が含まれています。" #. type: Bullet: ' 1. ' -#: ../text/chapter6.md:747 +#: ../text/chapter6.md:785 msgid "" "(Easy) Use PSCi to test the hash functions for each of the defined " "instances. _Note_: There is no provided unit test for this exercise." @@ -23300,7 +23373,7 @@ msgstr "" "*補足*：この演習には単体試験がありません。" #. type: Bullet: ' 1. ' -#: ../text/chapter6.md:747 +#: ../text/chapter6.md:785 msgid "" "(Medium) Write a function `arrayHasDuplicates`, which tests if an array has " "any duplicate elements based on both hash and value equality. First, check " @@ -23317,7 +23390,7 @@ msgstr "" "しょう。" #. type: Bullet: ' 1. ' -#: ../text/chapter6.md:747 +#: ../text/chapter6.md:785 msgid "" "(Medium) Write a `Hashable` instance for the following newtype which " "satisfies the type class law:" @@ -23326,7 +23399,7 @@ msgstr "" "ください。" #. type: Plain text -#: ../text/chapter6.md:750 +#: ../text/chapter6.md:788 #, no-wrap msgid "" " ```haskell\n" @@ -23336,7 +23409,7 @@ msgstr "" " {{#include ../exercises/chapter6/test/no-peeking/Solutions.purs:Hour}}\n" #. type: Plain text -#: ../text/chapter6.md:753 +#: ../text/chapter6.md:791 #, no-wrap msgid "" " {{#include ../exercises/chapter6/test/no-peeking/Solutions.purs:eqHour}}\n" @@ -23346,7 +23419,7 @@ msgstr "" " ```\n" #. type: Plain text -#: ../text/chapter6.md:756 +#: ../text/chapter6.md:794 #, no-wrap msgid "" " The newtype `Hour` and its `Eq` instance represent the type of integers modulo 12, so that 1 and 13 are identified as equal, for example. Prove that the type class law holds for your instance.\n" @@ -23359,7 +23432,7 @@ msgstr "" " *補足*：この演習にテストはありません。\n" #. type: Plain text -#: ../text/chapter6.md:760 +#: ../text/chapter6.md:798 msgid "" "In this chapter, we've been introduced to _type classes_, a type-oriented " "form of abstraction that enables powerful forms of code reuse. We've seen a " @@ -23374,7 +23447,7 @@ msgstr "" "た。" #. type: Plain text -#: ../text/chapter6.md:761 +#: ../text/chapter6.md:799 msgid "" "This chapter also introduced type class laws, a technique for proving " "properties about code that uses type classes for abstraction. Type class "