CodeMirror: JavaScript mode

JavaScript mode

// Demo code (the actual new parser character stream implementation)

function StringStream(string) {
  this.pos = 0;
  this.string = string;
}

StringStream.prototype = {
  done: function() {return this.pos >= this.string.length;},
  peek: function() {return this.string.charAt(this.pos);},
  next: function() {
    if (this.pos < this.string.length)
      return this.string.charAt(this.pos++);
  },
  eat: function(match) {
    var ch = this.string.charAt(this.pos);
    if (typeof match == "string") var ok = ch == match;
    else var ok = ch && match.test ? match.test(ch) : match(ch);
    if (ok) {this.pos++; return ch;}
  },
  eatWhile: function(match) {
    var start = this.pos;
    while (this.eat(match));
    if (this.pos > start) return this.string.slice(start, this.pos);
  },
  backUp: function(n) {this.pos -= n;},
  column: function() {return this.pos;},
  eatSpace: function() {
    var start = this.pos;
    while (/\s/.test(this.string.charAt(this.pos))) this.pos++;
    return this.pos - start;
  },
  match: function(pattern, consume, caseInsensitive) {
    if (typeof pattern == "string") {
      function cased(str) {return caseInsensitive ? str.toLowerCase() : str;}
      if (cased(this.string).indexOf(cased(pattern), this.pos) == this.pos) {
        if (consume !== false) this.pos += str.length;
        return true;
      }
    }
    else {
      var match = this.string.slice(this.pos).match(pattern);
      if (match && consume !== false) this.pos += match[0].length;
      return match;
    }
  }
};

JavaScript mode supports several configuration options:

json which will set the mode to expect JSON data rather than a JavaScript program.
jsonld which will set the mode to expect JSON-LD linked data rather than a JavaScript program (demo).
typescript which will activate additional syntax highlighting and some other things for TypeScript code (demo).
trackScope can be set to false to turn off tracking of local variables. This will prevent locals from getting the "variable-2" token type, and will break completion of locals with javascript-hint.
statementIndent which (given a number) will determine the amount of indentation to use for statements continued on a new line.
wordCharacters, a regexp that indicates which characters should be considered part of an identifier. Defaults to /[\w$]/, which does not handle non-ASCII identifiers. Can be set to something more elaborate to improve Unicode support.

MIME types defined: text/javascript, application/javascript, application/x-javascript, text/ecmascript, application/ecmascript, application/json, application/x-json, application/manifest+json, application/ld+json, text/typescript, application/typescript.