plpgsql: merge evalASt {quasiquote,macro}expand, add DEBUG-EVAL

env.get: loop instead of a recursion, string parameter (merged with vget), do not raise an exception when the key is missing. Split eval_ast in eval_{symbol,vector,map} in order to reduce the diff and improve readability of EVAL. Use existing blocks to declare variables near their use (several were unused). Simplify try*, perform TCO.
kanaka · Oct 25, 2024 · 4e529a0 · 4e529a0
1 parent ac666a1
commit 4e529a0
Show file tree

Hide file tree

Showing 11 changed files with 926 additions and 914 deletions.
diff --git a/impls/plpgsql/core.sql b/impls/plpgsql/core.sql
@@ -131,7 +131,7 @@ DECLARE
 BEGIN
     fname := types._valueToString(args[1]);
     IF fname NOT LIKE '/%' THEN
-        fname := types._valueToString(envs.vget(0, '*PWD*')) || '/' || fname;
+        fname := types._valueToString(envs.get(0, '*PWD*')) || '/' || fname;
     END IF;
 
     tmp := CAST(round(random()*1000000) AS varchar);

diff --git a/impls/plpgsql/envs.sql b/impls/plpgsql/envs.sql
@@ -91,43 +91,21 @@ BEGIN
     RETURN envs.vset(env, symkey, val);
 END; $$ LANGUAGE plpgsql;
 
--- envs.find
-CREATE FUNCTION envs.find(env integer, symkey varchar) RETURNS integer AS $$
+-- envs.get
+CREATE FUNCTION envs.get(env integer, symkey varchar) RETURNS integer AS $$
 DECLARE
     outer_id  integer;
     d         hstore;
-    val       integer;
 BEGIN
+  LOOP
     SELECT e.data, e.outer_id INTO d, outer_id FROM envs.env e
         WHERE e.env_id = env;
     IF d ? symkey THEN
-        RETURN env;
-    ELSIF outer_id IS NOT NULL THEN
-        RETURN envs.find(outer_id, symkey);
-    ELSE
-        RETURN NULL;
+        RETURN (SELECT data -> symkey FROM envs.env WHERE env_id = e);
     END IF;
-END; $$ LANGUAGE plpgsql;
-
-
--- envs.vget
-CREATE FUNCTION envs.vget(env integer, symkey varchar) RETURNS integer AS $$
-DECLARE
-    result  integer;
-    e       integer;
-BEGIN
-    e := envs.find(env, symkey);
-    --RAISE NOTICE 'envs.find env: %, symkey: % -> e: %', env, symkey, e;
-    IF e IS NULL THEN
-        RAISE EXCEPTION '''%'' not found', symkey;
-    ELSE
-        SELECT data -> symkey INTO result FROM envs.env WHERE env_id = e;
+    env := outer_id;
+    IF env IS NULL THEN
+        RETURN NULL;
     END IF;
-    RETURN result;
-END; $$ LANGUAGE plpgsql;
-
--- envs.get
-CREATE FUNCTION envs.get(env integer, key integer) RETURNS integer AS $$
-BEGIN
-    RETURN envs.vget(env, types._valueToString(key));
+  END LOOP;
 END; $$ LANGUAGE plpgsql;
diff --git a/impls/plpgsql/step2_eval.sql b/impls/plpgsql/step2_eval.sql
@@ -18,40 +18,45 @@ BEGIN
 END; $$ LANGUAGE plpgsql;
 
 -- eval
-CREATE FUNCTION mal.eval_ast(ast integer, env hstore) RETURNS integer AS $$
-DECLARE
-    type           integer;
-    symkey         varchar;
-    seq            integer[];
-    eseq           integer[];
-    hash           hstore;
-    ehash          hstore;
-    kv             RECORD;
-    e              integer;
-    result         integer;
-BEGIN
-    SELECT type_id INTO type FROM types.value WHERE value_id = ast;
-    CASE
-    WHEN type = 7 THEN
+
+CREATE FUNCTION mal.eval_symbol(ast integer, env hstore) RETURNS integer
+AS $$
+    DECLARE
+        symkey constant varchar := types._valueToString(ast);
     BEGIN
-        symkey := types._valueToString(ast);
         IF env ? symkey THEN
-            result := env -> symkey;
+            RETURN env -> symkey;
         ELSE
             RAISE EXCEPTION '''%'' not found', symkey;
         END IF;
     END;
-    WHEN type IN (8, 9) THEN
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION mal.eval_vector(ast integer, env hstore) RETURNS integer
+AS $$
+    DECLARE
+        seq    constant integer[] := types._valueToArray(ast);
+        eseq            integer[];
+        result          integer;
     BEGIN
-        SELECT val_seq INTO seq FROM types.value WHERE value_id = ast;
         -- Evaluate each entry creating a new sequence
-        FOR i IN 1 .. COALESCE(array_length(seq, 1), 0) LOOP
+        FOR i IN 1 .. array_length(seq, 1) LOOP
             eseq[i] := mal.EVAL(seq[i], env);
         END LOOP;
-        INSERT INTO types.value (type_id, val_seq) VALUES (type, eseq)
+        INSERT INTO types.value (type_id, val_seq) VALUES (9, eseq)
             RETURNING value_id INTO result;
+        RETURN result;
     END;
-    WHEN type = 10 THEN
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION mal.eval_map(ast integer, env hstore) RETURNS integer
+AS $$
+    DECLARE
+        hash   hstore;
+        ehash  hstore;
+        kv     RECORD;
+        e      integer;
+        result integer;
     BEGIN
         SELECT val_hash INTO hash FROM types.value WHERE value_id = ast;
         -- Evaluate each value for every key/value
@@ -63,36 +68,39 @@ BEGIN
                 ehash := ehash || hstore(kv.key, CAST(e AS varchar));
             END IF;
         END LOOP;
-        INSERT INTO types.value (type_id, val_hash) VALUES (type, ehash)
+        INSERT INTO types.value (type_id, val_hash) VALUES (10, ehash)
             RETURNING value_id INTO result;
+        RETURN result;
     END;
-    ELSE
-        result := ast;
-    END CASE;
-
-    RETURN result;
-END; $$ LANGUAGE plpgsql;
+$$ LANGUAGE plpgsql;
 
 CREATE FUNCTION mal.EVAL(ast integer, env hstore) RETURNS integer AS $$
 DECLARE
-    type     integer;
-    el       integer;
+    a0       integer;
     fname    varchar;
     args     integer[];
+    evda0    integer;
     result   integer;
 BEGIN
-    SELECT type_id INTO type FROM types.value WHERE value_id = ast;
-    IF type <> 8 THEN
-        RETURN mal.eval_ast(ast, env);
-    END IF;
+    CASE type_id FROM types.value WHERE value_id = ast
+    WHEN 7  THEN RETURN mal.eval_symbol(ast, env);
+    WHEN 8  THEN NULL;    --  List, proceed after this case statement.
+    WHEN 9  THEN RETURN mal.eval_vector(ast, env);
+    WHEN 10 THEN RETURN mal.eval_map(ast, env);
+    ELSE         RETURN ast;
+    END CASE;
+
     IF types._count(ast) = 0 THEN
         RETURN ast;
     END IF;
 
-    el := mal.eval_ast(ast, env);
+    a0 := types._first(ast);
+    evda0  := mal.EVAL(a0, env);
     SELECT val_string INTO fname FROM types.value
-        WHERE value_id = types._first(el);
-    args := types._restArray(el);
+        WHERE value_id = evda0;
+    FOR i in 0 .. types._count(ast) - 2 LOOP
+        args[i] := mal.EVAL(types._nth(ast, i+1), env);
+    END LOOP;
     EXECUTE format('SELECT %s($1);', fname) INTO result USING args;
     RETURN result;
 END; $$ LANGUAGE plpgsql;

diff --git a/impls/plpgsql/step3_env.sql b/impls/plpgsql/step3_env.sql
@@ -19,34 +19,57 @@ BEGIN
 END; $$ LANGUAGE plpgsql;
 
 -- eval
-CREATE FUNCTION mal.eval_ast(ast integer, env integer) RETURNS integer AS $$
+
+CREATE FUNCTION mal.eval_debug(ast integer, env integer) RETURNS void AS $$
 DECLARE
-    type           integer;
-    seq            integer[];
-    eseq           integer[];
-    hash           hstore;
-    ehash          hstore;
-    kv             RECORD;
-    e              integer;
-    result         integer;
+    val constant integer := envs.get(env, 'DEBUG-EVAL');
 BEGIN
-    SELECT type_id INTO type FROM types.value WHERE value_id = ast;
-    CASE
-    WHEN type = 7 THEN
+    IF val IS NOT NULL THEN
+        IF (SELECT type_id FROM types.value WHERE value_id = val) NOT IN (0, 1)
+        THEN
+            PERFORM io.writeline(format('EVAL: %s [%s]', mal.PRINT(ast), ast));
+        END IF;
+    END IF;
+END; $$ LANGUAGE plpgsql;
+
+CREATE FUNCTION mal.eval_symbol(ast integer, env integer) RETURNS integer
+AS $$
+    DECLARE
+        symkey constant varchar := types._valueToString(ast);
+        result constant integer := envs.get(env, symkey);
     BEGIN
-        result := envs.get(env, ast);
+         IF result IS NULL THEN
+            RAISE EXCEPTION '''%'' not found', symkey;
+        END IF;
+        RETURN result;
     END;
-    WHEN type IN (8, 9) THEN
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION mal.eval_vector(ast integer, env integer) RETURNS integer
+AS $$
+    DECLARE
+        seq    constant integer[] := types._valueToArray(ast);
+        eseq            integer[];
+        result          integer;
     BEGIN
-        SELECT val_seq INTO seq FROM types.value WHERE value_id = ast;
         -- Evaluate each entry creating a new sequence
-        FOR i IN 1 .. COALESCE(array_length(seq, 1), 0) LOOP
+        FOR i IN 1 .. array_length(seq, 1) LOOP
             eseq[i] := mal.EVAL(seq[i], env);
         END LOOP;
-        INSERT INTO types.value (type_id, val_seq) VALUES (type, eseq)
+        INSERT INTO types.value (type_id, val_seq) VALUES (9, eseq)
             RETURNING value_id INTO result;
+        RETURN result;
     END;
-    WHEN type = 10 THEN
+$$ LANGUAGE plpgsql;
+
+CREATE FUNCTION mal.eval_map(ast integer, env integer) RETURNS integer
+AS $$
+    DECLARE
+        hash   hstore;
+        ehash  hstore;
+        kv     RECORD;
+        e      integer;
+        result integer;
     BEGIN
         SELECT val_hash INTO hash FROM types.value WHERE value_id = ast;
         -- Evaluate each value for every key/value
@@ -58,76 +81,70 @@ BEGIN
                 ehash := ehash || hstore(kv.key, CAST(e AS varchar));
             END IF;
         END LOOP;
-        INSERT INTO types.value (type_id, val_hash) VALUES (type, ehash)
+        INSERT INTO types.value (type_id, val_hash) VALUES (10, ehash)
             RETURNING value_id INTO result;
+        RETURN result;
     END;
-    ELSE
-        result := ast;
-    END CASE;
-
-    RETURN result;
-END; $$ LANGUAGE plpgsql;
+$$ LANGUAGE plpgsql;
 
 CREATE FUNCTION mal.EVAL(ast integer, env integer) RETURNS integer AS $$
 DECLARE
-    type     integer;
     a0       integer;
-    a0sym    varchar;
-    a1       integer;
-    let_env  integer;
-    idx      integer;
-    binds    integer[];
-    el       integer;
-    fname    varchar;
-    args     integer[];
-    result   integer;
 BEGIN
-    -- PERFORM writeline(format('EVAL: %s [%s]', pr_str(ast), ast));
-    SELECT type_id INTO type FROM types.value WHERE value_id = ast;
-    IF type <> 8 THEN
-        RETURN mal.eval_ast(ast, env);
-    END IF;
+    PERFORM mal.eval_debug(ast, env);
+
+    CASE type_id FROM types.value WHERE value_id = ast
+    WHEN 7  THEN RETURN mal.eval_symbol(ast, env);
+    WHEN 8  THEN NULL;    --  List, proceed after this case statement.
+    WHEN 9  THEN RETURN mal.eval_vector(ast, env);
+    WHEN 10 THEN RETURN mal.eval_map(ast, env);
+    ELSE         RETURN ast;
+    END CASE;
+
     IF types._count(ast) = 0 THEN
         RETURN ast;
     END IF;
 
     a0 := types._first(ast);
     IF types._symbol_Q(a0) THEN
-        a0sym := (SELECT val_string FROM types.value WHERE value_id = a0);
-    ELSE
-        a0sym := '__<*fn*>__';
-    END IF;
 
-    CASE
-    WHEN a0sym = 'def!' THEN
-    BEGIN
+    CASE val_string FROM types.value WHERE value_id = a0
+
+    WHEN 'def!' THEN
         RETURN envs.set(env, types._nth(ast, 1),
                         mal.EVAL(types._nth(ast, 2), env));
-    END;
-    WHEN a0sym = 'let*' THEN
+
+    WHEN 'let*' THEN
+    DECLARE
+        let_env constant integer   := envs.new(env);
+        binds   constant integer[] := types._valueToArray(types._nth(ast, 1));
     BEGIN
-        let_env := envs.new(env);
-        a1 := types._nth(ast, 1);
-        binds := (SELECT val_seq FROM types.value WHERE value_id = a1);
-        idx := 1;
-        WHILE idx < array_length(binds, 1) LOOP
+        FOR idx IN 1 .. array_length(binds, 1) BY 2 LOOP
             PERFORM envs.set(let_env, binds[idx],
                                       mal.EVAL(binds[idx+1], let_env));
-            idx := idx + 2;
         END LOOP;
         RETURN mal.EVAL(types._nth(ast, 2), let_env);
     END;
     ELSE
+        NULL;
+    END CASE;
+    END IF;
+    --  Apply phase.
+    DECLARE
+        fname            varchar;
+        args             integer[];
+        result           integer;
+        evda0   constant integer := mal.EVAL(a0, env);
     BEGIN
-        el := mal.eval_ast(ast, env);
         SELECT val_string INTO fname FROM types.value
-            WHERE value_id = types._first(el);
-        args := types._restArray(el);
+            WHERE value_id = evda0;
+        FOR i in 0 .. types._count(ast) - 2 LOOP
+            args[i] := mal.EVAL(types._nth(ast, i+1), env);
+        END LOOP;
         EXECUTE format('SELECT %s($1);', fname)
             INTO result USING args;
         RETURN result;
     END;
-    END CASE;
 END; $$ LANGUAGE plpgsql;
 
 -- print