refactor ffi and rename to

src/gleam/regexp.gleam

@@ -226,12 +226,12 @@ pub fn replace(
 ///
 /// ```gleam
 /// let assert Ok(re) = regexp.from_string("\\w+")
-/// regexp.replace_map(re, "hello, joe!", fn(m) { string.capitalise(m.content) })
+/// regexp.match_map(re, "hello, joe!", fn(m) { string.capitalise(m.content) })
 /// // -> "Hello, Joe!"
 /// ```
-@external(erlang, "gleam_regexp_ffi", "replace_map")
-@external(javascript, "../gleam_regexp_ffi.mjs", "replace_map")
-pub fn replace_map(
+@external(erlang, "gleam_regexp_ffi", "match_map")
+@external(javascript, "../gleam_regexp_ffi.mjs", "match_map")
+pub fn match_map(
   each pattern: Regexp,
   in string: String,
   with substitute: fn(Match) -> String,

src/gleam_regexp_ffi.erl

@@ -1,6 +1,6 @@
 -module(gleam_regexp_ffi).
 
--export([compile/2, check/2, split/2, replace/3, scan/2, replace_map/3]).
+-export([compile/2, check/2, split/2, replace/3, scan/2, match_map/3]).
 
 compile(String, Options) ->
     {options, Caseless, Multiline} = Options,
@@ -44,9 +44,9 @@ scan(Regexp, String) ->
 replace(Regexp, Subject, Replacement) ->
     re:replace(Subject, Regexp, Replacement, [global, {return, binary}]).
 
-replace_map(Regexp, Subject, Replacement) ->
+match_map(Regexp, Subject, Replacement) ->
     Replacement1 = fun(Content, Submatches) ->
-        Submatches1 = gleam@list:map(Submatches, fun gleam@string:to_option/1),
+        Submatches1 = lists:map(fun gleam@string:to_option/1, Submatches),
         Replacement({match, Content, Submatches1})
     end,
     re:replace(Subject, Regexp, Replacement1, [global, {return, binary}]).

src/gleam_regexp_ffi.mjs

@@ -31,17 +31,7 @@ export function split(regex, string) {
 export function scan(regex, string) {
   const matches = Array.from(string.matchAll(regex)).map((match) => {
     const content = match[0];
-    const submatches = [];
-    for (let n = match.length - 1; n > 0; n--) {
-      if (match[n]) {
-        submatches[n - 1] = new Some(match[n]);
-        continue;
-      }
-      if (submatches.length > 0) {
-        submatches[n - 1] = new None();
-      }
-    }
-    return new RegexMatch(content, List.fromArray(submatches));
+    return new RegexMatch(content, submatches(match.slice(1)));
   });
   return List.fromArray(matches);
 }
@@ -50,22 +40,26 @@ export function replace(regex, original_string, replacement) {
   return original_string.replaceAll(regex, replacement);
 }
 
-export function replace_map(regex, original_string, replacement) {
+export function match_map(regex, original_string, replacement) {
   let replace = (match, ...args) => {
     const hasNamedGroups = typeof args.at(-1) === "object";
     const groups = args.slice(0, hasNamedGroups ? -3 : -2);
-    const submatches = [];
-    for (let n = 0; n < groups.length; n++) {
-      if (groups[n]) {
-        submatches[n] = new Some(groups[n]);
-        continue;
-      }
-      if (submatches.length > 0) {
-        submatches[n] = new None();
-      }
-    }
-    let regexMatch = new RegexMatch(match, List.fromArray(submatches));
+    let regexMatch = new RegexMatch(match, submatches(groups));
     return replacement(regexMatch);
   };
   return original_string.replaceAll(regex, replace);
 }
+
+function submatches(groups) {
+  const submatches = [];
+  for (let n = groups.length - 1; n >= 0; n--) {
+    if (groups[n]) {
+      submatches[n] = new Some(groups[n]);
+      continue;
+    }
+    if (submatches.length > 0) {
+      submatches[n] = new None();
+    }
+  }
+  return List.fromArray(submatches);
+}

test/gleam_regexp_test.gleam

@@ -191,7 +191,7 @@ pub fn replace_3_test() {
   |> should.equal("🐕🐕 are great!")
 }
 
-pub fn replace_map_0_test() {
+pub fn match_map_0_test() {
   let replace = fn(match: Match) {
     case match.content {
       "1" -> "one"
@@ -201,11 +201,11 @@ pub fn replace_map_0_test() {
     }
   }
   let assert Ok(re) = regexp.from_string("1|2|3")
-  regexp.replace_map(re, "1, 2, 3, 4", replace)
+  regexp.match_map(re, "1, 2, 3, 4", replace)
   |> should.equal("one, two, three, 4")
 }
 
-pub fn replace_map_1_test() {
+pub fn match_map_1_test() {
   let replace = fn(match: Match) {
     case match.submatches {
       [Some("1")] -> "one"
@@ -215,6 +215,6 @@ pub fn replace_map_1_test() {
     }
   }
   let assert Ok(re) = regexp.from_string("'(1|2|3)'")
-  regexp.replace_map(re, "'1', '2', '3', '4'", replace)
+  regexp.match_map(re, "'1', '2', '3', '4'", replace)
   |> should.equal("one, two, three, '4'")
 }