From 36f78982e616e88a6c867d45c7ea601a34010d19 Mon Sep 17 00:00:00 2001
From: Tangent Wantwight <tangent128@gmail.com>
Date: Sat, 29 Jul 2023 16:26:41 -0400
Subject: [PATCH] Make pattern mapping chained

---
 notcl.js | 52 +++++++++++++++++++---------------------------------
 peg.js   | 39 +++++++++++++++++++++------------------
 2 files changed, 40 insertions(+), 51 deletions(-)

diff --git a/notcl.js b/notcl.js
index be89430..726b71c 100644
--- a/notcl.js
+++ b/notcl.js
@@ -6,7 +6,7 @@
  */
 
 var Notcl = (() => {
-  const { AtLeast, Choose, End, Map, Regex, Sequence, Use } = Peg;
+  const { AtLeast, Choose, End, Regex, Sequence, Use } = Peg;
 
   const InterCommandWhitespace = Regex(/\s+/y);
 
@@ -16,52 +16,38 @@ var Notcl = (() => {
 
   const PreWordWhitespace = Regex(/[^\S\n;]*/y);
 
-  const BasicWord = Map(Regex(/[^\s;]+/y), ([word]) => ({
-    text: word,
-  }));
+  const BasicWord = Regex(/[^\s;]+/y).map(([word]) => ({ text: word }));
 
   // WIP, need to be able to escape braces correctly
   // WIP, error if anything after closing brace
 
   /** @type {Peg.Pattern<string>} */
-  const Brace = Map(
-    Sequence(
-      Regex(/\{/y),
-      AtLeast(
-        0,
-        Choose(
-          Map(
-            Use(() => Brace),
-            (text) => `{${text}}`
-          ),
-          Map(Regex(/[^{}]+/y), ([text]) => text)
-        )
-      ),
-      Regex(/\}/y)
-    ),
-    ([_left, fragments, _right]) => fragments.join("")
-  );
-
-  const Word = Map(
-    Sequence(
-      PreWordWhitespace,
+  const Brace = Sequence(
+    Regex(/\{/y),
+    AtLeast(
+      0,
       Choose(
-        Map(Brace, (text) => ({
-          text,
-        })),
-        BasicWord
+        Use(() => Brace).map((text) => `{${text}}`),
+        Regex(/[^{}]+/y).map(([text]) => text)
       )
     ),
-    ([_, word]) => word
-  );
+    Regex(/\}/y)
+  ).map(([_left, fragments, _right]) => fragments.join(""));
+
+  const Word = Sequence(
+    PreWordWhitespace,
+    Choose(
+      Brace.map((text) => ({ text })),
+      BasicWord
+    )
+  ).map(([_, word]) => word);
 
   const CommandTerminator = Sequence(
     PreWordWhitespace,
     Choose(/** @type {Peg.Pattern<unknown>} */ (Regex(/[\n;]/y)), End)
   );
 
-  const Command = Map(
-    Sequence(PreCommand, AtLeast(0, Word), CommandTerminator),
+  const Command = Sequence(PreCommand, AtLeast(0, Word), CommandTerminator).map(
     ([_padding, words, _end]) => words
   );
 
diff --git a/peg.js b/peg.js
index 2c81c0e..38a206c 100644
--- a/peg.js
+++ b/peg.js
@@ -4,9 +4,19 @@
  * If it matches successfully, it returns some captured value, and the index following the match.
  *
  * @template T
- * @typedef {{
- *   (source: string, index: number): ([T, number] | null)
- * }} Peg.Pattern
+ * @callback Peg.PatternCall
+ * @param {string} source - the string being parsed
+ * @param {number} index - the index in the string to begin matching from
+ * @returns {[T, number] | null} - if successful, the captured value & the index to start parsing following symbols from. Else, null.
+ */
+/**
+ * @template T
+ * @typedef {object} Peg.PatternExt
+ * @property {<U>(map: (value: T) => U) => Peg.Pattern<U>} map Creates a pattern that wraps another pattern, transforming the returned value on a match
+ */
+/**
+ * @template T
+ * @typedef {Peg.PatternCall<T> & Peg.PatternExt<T>} Peg.Pattern
  */
 var Peg = window.Peg ?? {};
 
@@ -18,6 +28,13 @@ var Peg = window.Peg ?? {};
  * @returns {Peg.Pattern<T>}
  */
 Peg.WrapPattern = function (pattern) {
+  /** @type {Peg.Pattern<T>} */ (pattern).map = function (map) {
+    return Peg.WrapPattern(function (source, index) {
+      const match = pattern(source, index);
+      return match ? [map(match[0]), match[1]] : null;
+    });
+  };
+
   return /** @type {Peg.Pattern<T>} */ (pattern);
 };
 
@@ -36,20 +53,6 @@ Peg.Use = function (getPattern) {
   });
 };
 
-/**
- * Creates a pattern that wraps another pattern, transforming the returned value on a match
- * @template T, U
- * @param {Peg.Pattern<T>} pattern
- * @param {(value: T)=> U} map
- * @return {Peg.Pattern<U>}
- */
-Peg.Map = function (pattern, map) {
-  return Peg.WrapPattern(function (source, index) {
-    const match = pattern(source, index);
-    return match ? [map(match[0]), match[1]] : null;
-  });
-};
-
 /**
  * Creates a pattern matching a regex & returning any captures. The regex needs to be sticky (using the //y modifier)
  * @param {RegExp} regex
@@ -108,7 +111,7 @@ Peg.Sequence = function (...patterns) {
 /**
  * Creates a pattern that matches consecutive runs of the given pattern, returning an array of all captures.
  *
- * The match only succeeds if the run is at least {min} instances long.
+ * The match only succeeds if the run is at least {@link min} instances long.
  *
  * If the given pattern does not consume input, the matching will be terminated to prevent an eternal loop.
  *