factor out the code to divide input lines into code/text chunks

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: knitr
 Type: Package
 Title: A General-Purpose Package for Dynamic Report Generation in R
-Version: 1.46.2
+Version: 1.46.3
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "[email protected]", comment = c(ORCID = "0000-0003-0645-5666")),
     person("Abhraneel", "Sarma", role = "ctb"),

R/parser.R

@@ -13,8 +13,7 @@ split_file = function(lines, set.preamble = TRUE, patterns = knit_patterns$get()
   }
 
   markdown_mode = identical(patterns, all_patterns$md)
-  i = group_indices(grepl(chunk.begin, lines), grepl(chunk.end, lines), lines, markdown_mode)
-  groups = unname(split(lines, i))
+  groups = divide_chunks(lines, chunk.begin, chunk.end, markdown_mode)
 
   if (set.preamble)
     knit_concord$set(inlines = sapply(groups, length)) # input line numbers for concordance
@@ -41,6 +40,12 @@ split_file = function(lines, set.preamble = TRUE, patterns = knit_patterns$get()
   })
 }
 
+# divide lines of input into code/text chunks
+divide_chunks = function(x, begin, end, md = TRUE) {
+  i = group_indices(grepl(begin, x), grepl(end, x), x, md)
+  unname(split(x, i))
+}
+
 extract_params_src = function(chunk.begin, line) {
   trimws(gsub(chunk.begin, '\\1', line))
 }