feat: add new parser file to use rudus

#119

Author: Bikossor

src/parser/JavaScript-rudus.ts

@@ -0,0 +1,54 @@
+import {
+  anyOf,
+  regex,
+  sequenceOf,
+  string,
+  optional,
+  whitespace,
+  between,
+} from "rudus";
+
+console.time();
+
+const betweenDoubleQuotes = between(string('"'));
+const optionalWhitespace = optional(whitespace());
+
+const declarationKeyword = regex(/^var|let|const/);
+const word = regex(/\w+/); // word
+const equalSign = string("=");
+
+const literalBool = regex(/true|false/);
+const literalUndefined = regex(/undefined/);
+const literalNull = regex(/null/);
+const literalNumber = regex(/^(\d+\.)?\d+$|^0b[0-1]+(n)?$/);
+const literalString = betweenDoubleQuotes(word);
+
+const variableValue = anyOf([
+  literalBool,
+  literalString,
+  literalNumber,
+  literalUndefined,
+  literalNull,
+]);
+
+const variableParser = sequenceOf([
+  declarationKeyword.map(
+    state => `<span style="color:red">${state.result}</span>`,
+  ),
+  optionalWhitespace,
+  word.map(state => `<span style="color:green">${state.result}</span>`),
+  optionalWhitespace,
+  equalSign.map(state => `<span style="color:grey">${state.result}</span>`),
+  optionalWhitespace,
+  variableValue.map(state => `<span style="color:blue">${state.result}</span>`),
+]);
+
+const parserResult = variableParser.run("const isCool = null");
+
+console.timeEnd();
+
+if (parserResult.isError) {
+  console.log(parserResult.errorMessage);
+} else {
+  console.log(parserResult.result);
+}