improve parser memoization

Author: neverRare

dictionary/parser.ts

@@ -491,13 +491,13 @@ const dictionaryParser = spaces
       ),
     )
   )
-  .parser();
+  .generateParser();
 
 const definitionExtractor = spaces
   .with(all(optionalAll(lex(head)).with(lex(match(/[^;]*;/, "definition")))))
   .skip(end)
-  .parser();
-const definitionParser = spaces.with(definition).skip(end).parser();
+  .generateParser();
+const definitionParser = spaces.with(definition).skip(end).generateParser();
 
 export function parseDictionary(sourceText: string): Dictionary {
   const arrayResult = dictionaryParser(sourceText);

misc/misc.ts

@@ -49,3 +49,14 @@ export function compound(
     return `${initText} ${conjunction} ${last}`;
   }
 }
+export function lazy<T>(fn: () => T): () => T {
+  let defined = false;
+  let value: null | T;
+  return () => {
+    if (!defined) {
+      defined = true;
+      value = fn();
+    }
+    return value!;
+  };
+}

src/cache.ts

@@ -1,4 +1,4 @@
-import { Lazy } from "./cache.ts";
+import { lazy } from "../misc/misc.ts";
 
 export const checkLocalStorage = lazy(() => {
   // https://developer.mozilla.org/en-US/docs/Web/API/Web_Storage_API/Using_the_Web_Storage_API
@@ -28,7 +28,3 @@ export function setIgnoreError(key: string, value: string): void {
     }
   }
 }
-function lazy<T>(fn: () => T): () => T {
-  const cache = new Lazy(fn);
-  return () => cache.getValue();
-}

src/local_storage.ts

@@ -16,7 +16,6 @@ import { loadCustomDictionary } from "./dictionary.ts";
 import { checkLocalStorage, setIgnoreError } from "./local_storage.ts";
 import { flattenError } from "../misc/misc.ts";
 import { translate } from "./mod.ts";
-import { clearCache } from "./parser/cache.ts";
 import { settings } from "./settings.ts";
 import {
   loadFromElements,
@@ -219,7 +218,6 @@ function main(): void {
   confirmButton.addEventListener("click", () => {
     loadFromElements();
     updateLabel();
-    clearCache();
     settingsDialogBox.close();
   });
   cancelButton.addEventListener("click", () => {
@@ -271,7 +269,6 @@ function main(): void {
     try {
       loadCustomDictionary(value);
       setIgnoreError(DICTIONARY_KEY, value);
-      clearCache();
       customDictionaryDialogBox.close();
     } catch (error) {
       const errors = flattenError(error);

src/main.ts

@@ -8,7 +8,6 @@ import { translate as rawTranslate } from "./translator/translator.ts";
 
 export { ArrayResultError, type ArrayResultOptions } from "./array_result.ts";
 export { loadCustomDictionary } from "./dictionary.ts";
-export { clearCache } from "./parser/cache.ts";
 export {
   defaultSettings,
   type RedundancySettings,

src/mod.ts

@@ -1,6 +1,5 @@
 import { sumOf } from "@std/collections/sum-of";
 import { settings } from "../settings.ts";
-import { cache } from "./cache.ts";
 import {
   all,
   allAtLeastOnce,
@@ -207,8 +206,6 @@ const combinedGlyphsToken = combinedGlyphs
   .map((words) => ({ type: "combined glyphs", words }) as const);
 const wordToken = word.map((word) => ({ type: "word", word }) as const);
 
-Parser.startCache(cache);
-
 export const token = choiceOnlyOne<Token>(
   xAlaX,
   multipleA,
@@ -226,5 +223,3 @@ export const token = choiceOnlyOne<Token>(
   headlessLongGlyphStart,
   insideLongGlyph,
 );
-
-Parser.endCache();

src/parser/cache.ts

@@ -24,7 +24,6 @@ import {
   SimpleHeadedWordUnit,
   SimpleWordUnit,
 } from "./ast.ts";
-import { cache } from "./cache.ts";
 import { everyWordUnitInSentence } from "./extract.ts";
 import {
   CLAUSE_RULE,
@@ -59,11 +58,10 @@ import {
   UnrecognizedError,
 } from "./parser_lib.ts";
 import { describe, Token } from "./token.ts";
+import { lazy as lazyEval } from "../../misc/misc.ts";
 
 const spaces = match(/\s*/, "spaces");
 
-Parser.startCache(cache);
-
 const specificToken = memoize(
   <T extends Token["type"]>(type: T): Parser<Token & { type: T }> =>
     token.map((token) =>
@@ -219,7 +217,7 @@ function optionalCombined(
   );
 }
 const number = manyAtLeastOnce(wordFrom(numeralSet, "numeral"));
-const phrase: Parser<Phrase> = lazy(() =>
+const phrase: Parser<Phrase> = lazy(lazyEval(() =>
   choice<Phrase>(
     sequence(
       number,
@@ -273,7 +271,7 @@ const phrase: Parser<Phrase> = lazy(() =>
       })),
   )
     .filter(filter(PHRASE_RULE))
-);
+));
 const nanpa = sequence(wordUnit(new Set(["nanpa"]), '"nanpa"'), phrase)
   .map(([nanpa, phrase]) => ({ nanpa, phrase }))
   .filter(filter(NANPA_RULES));
@@ -723,6 +721,4 @@ export const parse = spaces
       .filter(filter(MULTIPLE_SENTENCES_RULE))
       .map((sentences) => ({ type: "sentences", sentences })),
   ))
-  .parser();
-
-Parser.endCache();
+  .generateParser();