reduce caching

Author: neverRare

src/parser/lexer.ts

@@ -116,8 +116,6 @@ const longWord = choiceOnlyOne(matchString("a"), matchString("n"))
   )
   .skip(spaces);
 
-Parser.startCache(cache);
-
 /** Parses X ala X constructions if allowed by the settings. */
 const xAlaX = lazy(() => {
   if (settings.xAlaXPartialParsing) {
@@ -131,8 +129,6 @@ const xAlaX = lazy(() => {
 })
   .map<Token>((word) => ({ type: "x ala x", word }));
 
-Parser.endCache();
-
 /** Parses a punctuation. */
 const punctuation = choiceOnlyOne(
   match(/[.,:;?!…·。｡︒\u{F199C}\u{F199D}]+/u, "punctuation")

src/parser/parser-lib.ts

@@ -17,9 +17,13 @@ export class Parser<T> {
   readonly #parser: (src: string) => ParserResult<T>;
   static cache: null | Cache = null;
   constructor(parser: (src: string) => ParserResult<T>) {
-    const cache = new Map<string, ParserResult<T>>();
-    Parser.addToCache(cache);
-    this.#parser = memoize(parser, { cache });
+    if (Parser.cache != null) {
+      const cache = new Map<string, ParserResult<T>>();
+      Parser.addToCache(cache);
+      this.#parser = memoize(parser, { cache });
+    } else {
+      this.#parser = parser;
+    }
   }
   parser(src: string): ParserResult<T> {
     return ArrayResult.from(() => this.#parser(src));