test.js

function trimComment(str){
  var lines = str.split(/\n|\r\n/);
  var end = lines.length-1;
  var current = 0;

  var buffer = lines[current];
  var exps = [];
  // 現在primary expressionの立ち居地にあるのかどうかをtestする
  // 直前のものしか調べてないから, 正確性に欠けるかも...
  function isPrimary(exps){
    var len = exps.length;
    if(len === 0){
      return true;
    }
    // len !== 0
    if(exps[len-1].type === 'IDENT'){
      var val = exps[len-1].val;
      return val === 'new' || val === 'typeof' || val === 'void' || val === 'delete' || val === 'instanceof' || val === 'in' || val === 'case' || 'throw' || val === 'do' || val === 'else' || val === 'return';
    }
    if(exps[len-1].type === 'OP'){
      var val = exps[len-1].val;
      return val === '+' ||
             val === '-' ||
             val === '!' ||
             val === '*' ||
             val === '/' ||
             val === '%' ||
             val === '~' ||
             val === '>>' ||
             val === '<<' ||
             val === '>>>'||
             val === '>' ||
             val === '<' ||
             val === '<=' ||
             val === '>=' ||
             val === '==' ||
             val === '!=' ||
             val === '==='||
             val === '!=='||
             val === '&' ||
             val === '^' ||
             val === '|' ||
             val === '&&' ||
             val === '||' ||
             val === ':' ||
             val === '?' ||
             val === ',' ||
             val === '=' ||
             val === '*=' ||
             val === '/=' ||
             val === '%=' ||
             val === '+=' ||
             val === '-=' ||
             val === '>>=' ||
             val === '<<=' ||
             val === '>>>=' ||
             val === '&=' ||
             val === '^=' ||
             val === '|=' ||
             val === '[' ||
             val === '}' ||
             val === ';' ||
             val === ')' ||
             val === '(';
    }
    return false;
  }
  var comment = false;
  var single_comment = false;
  var invalid = false;
  var result = [];
  var match = null;
  while(true){
    if(!buffer){
      if(current === end){
        break;
      }
      current+=1;
      buffer = lines[current];
      if(!comment && !single_comment)
        result.push("\n");
    } else if(comment){
      if(/\*\//.test(buffer)){
        buffer = RegExp.rightContext;
        comment = false;
      } else {
        buffer = null;
      }
    } else {
      if(/^[ \t\r\n]+/.test(buffer)){
        result.push(RegExp.lastMatch);
        buffer = RegExp.rightContext;
      } else if(/^\//.test(buffer)){
        // 正規表現は/や*から始まらない RegularExpressionFirstChar
        // よって即座に判断可能
        if(/^\/\//.test(buffer)){
          buffer = null;
        } else if(/^\/\*/.test(buffer)){
          buffer = RegExp.rightContext;
          comment = true;
        } else {
          // 正規表現の可能性がある
          // 現在PrimaryExpressionがこれるかどうか
          if(isPrimary(exps)){
            if(/^\/(?:[^\/\\]|\\.)?(?:\[.*\]|[^\/\\]|\\.)*\/[igIG]*/.test(buffer)){
              result.push(RegExp.lastMatch);
              buffer = RegExp.rightContext;
              exps.push({
                type: "REGEXP",
                val : RegExp.lastMatch
              });
            } else {
              invalid = true;
              break;
            }
          } else if(/^\/=|^\//.test(buffer)){
            result.push(RegExp.lastMatch);
            buffer = RegExp.rightContext;
            exps.push({
              type: "OP",
              val : RegExp.lastMatch
            });
          }
        }
      } else if(/^"(?:[^"\\]|\\.)*"|^'(?:[^'\\]|\\.)*'/.test(buffer)){
        result.push(RegExp.lastMatch);
        buffer = RegExp.rightContext;
        exps.push({
          type: "STRING",
          val : RegExp.lastMatch
        });
      } else if(/^0x[0-9A-Fa-f]+|^[0-9]*\.[0-9]+(?:e|E)(?:\-|\+|)[0-9]+|^[0-9]+(?:e|E)(?:\-|\+|)[0-9]+|^[0-9]*\.[0-9]+|^[0-9]+/.test(buffer)){
        result.push(RegExp.lastMatch);
        buffer = RegExp.rightContext;
        exps.push({
          type: "NUMBER",
          val : RegExp.lastMatch
        });
      } else if(/^[_\$A-Za-z][_\$0-9A-Za-z]*/.test(buffer)){
        result.push(RegExp.lastMatch);
        buffer = RegExp.rightContext;
        exps.push({
          type: "IDENT",
          val : RegExp.lastMatch
        });
      } else if(/^===|^!==|^>>>=|^>>>|^>>=|^<<=|^\-\-|^\+\+|^>>|^\|\||^\|=|^\^=|^>=|^==|^<=|^&=|^&&|^!=|^\+=|^\/=|^\-=|^\*=|^%=|^<<|^\}|^\||^\{|^\^|^\[|^\?|^=|^;|^:|^,|^\(|^&|^!|^~|^\+|^>|^<|^\]|^\/|^.|^\*|^\)|^%/.test(buffer)){
        result.push(RegExp.lastMatch);
        buffer = RegExp.rightContext;
        exps.push({
          type: "OP",
          val : RegExp.lastMatch
        });
      } else {
        invalid = true;
        break;
      }
    }
  }
  return (invalid)? "invalid result" : result.join("");
}

var val = <><![CDATA[
function ok(){
  // single line comment
  var comment = "これは//こめんとじゃないよ!"
  /* multiple comment */
  /*
  *
  *
  */
  var i = /.\/*/;// 正規表現...
  print(i);
}
]]></>.trim();
print("===============ORIGINAL=================");
print(val);
print("================TRIMED==================");
print(trimComment(val));

print(trimComment('hel/*as/[/*]/df*/lo /\\/*hello[*/]///asdf'));
print("var i = ~~/0[/*]/; // asa");
print(trimComment("var i = +/0[/*]/; // asa"));
print(trimComment("var i = 10;if(true){ i *= /0[/*]/;}; i = 0 * /0[/*]/;// asa"));

print("ORIGINAL");
print("var i = 100 / 10 / [1,2,3][~~/[/*]/] // hogeeee");
print("TRIMED");
print(trimComment("var i = 100 / 10 / [1,2,3][~~/[/*]/] // hogeeee"));