Custom parser for Codemirror for presell seo articles

seo.js

Array.prototype.last = function() {
    return this[this.length-1];
}

Array.prototype.random = function () {
       return this[Math.floor(Math.random()*this.length)];
 }

String.prototype.sample = function(start,end) {
  res="";
  var maxl=(typeof(end)=='undefined' ? this.length : end+1);
  for(i=(typeof(start)=='undefined' ? 0 : start);i<maxl;i++)
  {
    ch=this[i];
    if(ch=='{')
    {
      tmp=this.sampleParse(i);
      res+=tmp.res;
      i=tmp.pos;
    }
    else
      res+=ch;
  }
  return res;
}

String.prototype.sampleParse = function(start){
  var options=[];
  var optionVal='';
  maxl=this.length;
  i=0;
  for(i=start+1;i<maxl;i++){
    ch=this[i];
    if(ch=='{')
    {
      tmp=this.sampleParse(i);
      optionVal+=tmp.res;
      i=tmp.pos;
    }
    else if(ch=='|')
    {
      options.push(optionVal);
      optionVal='';
    }
    else if(ch=='}')
    {
      options.push(optionVal);
      return {res:options.random(),pos:i};
    }
    else { optionVal+=ch; }
  }
  return {res:'ERROR',pos:i};
}

CodeMirror.seoRangeFinder = function(cm, start) {
  var line = start.line, lineText = cm.getLine(line);
  var at = lineText.length, startChar, tokenType;
  for (;;) {
    var found = lineText.lastIndexOf("{", at);
    if (found < start.ch) break;
    startChar = found;
  }
  if (startChar == null) return;
  var count = 1, lastLine = cm.lineCount(), end, endCh;
  outer: for (var i = line; i < lastLine; ++i) {
    var text = cm.getLine(i), pos = (i==line ? startChar:0);
    for (;;) {
      var nextOpen = text.indexOf("{", pos), nextClose = text.indexOf("}", pos);
      if (nextOpen < 0) nextOpen = text.length;
      if (nextClose < 0) nextClose = text.length;
      pos = Math.min(nextOpen, nextClose);
      if (pos == text.length) break;
        if (pos == nextOpen) ++count;
        else if (!--count) { end = i; endCh = pos; break outer; }
      ++pos;
    }
  }
  if (end == null) return;
  return {from: CodeMirror.Pos(line, startChar),
          to: CodeMirror.Pos(end, endCh+1)};
};

Array.prototype.setLast = function(val) {
    this[this.length-1]=val;
}

CodeMirror.defineMode("seo", function() {
    function tokenBase (stream, state	) {
    		var styles=[];
            var ch = stream.next();
			var start=false;
			var level=state.level;
			var currentOption=state.optionNR.last();
			
			
			if(ch==' ' && ((state.befores.last()==' ' && state.option_start)||state.last_char==' '))
				styles.push('double-space');
            else if(!/\s/.test(ch) && ch!='}' && ch!='{' && ch!='|' && ((/[,.]/.test(state.befores.last()) && state.option_start)||/[,.]/.test(state.last_char)))
				{
				styles.push('missing-space');
				}
			
			if(/[a-zżźćńółęąś]/.test(ch) && ((/[.]/.test(state.befores_nowhite.last()) && state.option_start)||/[.]/.test(state.last_nowhite_char)))
				styles.push('upcase-mistake');
			
			if (ch == '}') {
				if(level==0)
					styles.push('unexpected-token');
				else
				{
					state.befores.pop();
					state.optionNR.pop();	
					state.befores_nowhite.pop();
					
	                styles.push("tag"+level);
					state.last_char=undefined;
					state.last_nowhite_char=undefined;
					state.level--;
				}
            }
			else if (ch == "{") {
				start=true;
				state.befores.push(state.last_char==undefined ? state.befores.last() : state.last_char);
				state.befores_nowhite.push(state.last_nowhite_char==undefined ? state.befores_nowhite.last() : state.last_nowhite_char);
				styles.push("tag"+(level+1));
				state.optionNR.push(0);				
				state.level++;
        if(state.level==1)
          state.groupId++;
			}
			else if (ch == "|") {
				if(level==0)
				  styles.push('unexpected-token');
				else
					{
					start=true;
					state.optionNR.setLast(currentOption+1);	
					styles.push("tag"+level);
					state.last_char=undefined;
					state.last_nowhite_char=undefined;
					}
			}
			
            else 
				{
				styles.push("keyword"+level);
				if(typeof(currentOption)=="number")
					styles.push("option"+currentOption);
				state.last_char=(stream.eol() ? "\n":ch);
				if(!/\s/.test(ch))
					state.last_nowhite_char=ch;
				
				}
			
      if(state.level>0 || ch=='}')
        styles.push("group"+state.groupId);
			state.option_start=start;
			return styles.join(' ');
    }
   
    return {
        startState: function () {
            return {tokenize: tokenBase,option_start:false,level:0,groupStart:undefined,groupEnd:undefined,groupId:0,last_nowhite_char:undefined,last_char:undefined,befores:[],optionNR:[],befores_nowhite:[]};
        },
        token: function (stream, state) {
            return state.tokenize(stream, state);
        }
    }; 
});