dojo.provide("dojo.regexp");

/*=====
dojo.regexp = {
	// summary: Regular expressions and Builder resources
};
=====*/

dojo.regexp.escapeString = function(/*String*/str, /*String?*/except){
	//	summary:
	//		Adds escape sequences for special characters in regular expressions
	// except:
	//		a String with special characters to be left unescaped

//	return str.replace(/([\f\b\n\t\r[\^$|?*+(){}])/gm, "\\$1"); // string
	return str.replace(/([\.$?*!=:|{}\(\)\[\]\\\/^])/g, function(ch){
		if(except && except.indexOf(ch) != -1){
			return ch;
		}
		return "\\" + ch;
	}); // String
}

dojo.regexp.buildGroupRE = function(/*Object|Array*/arr, /*Function*/re, /*Boolean?*/nonCapture){
	//	summary:
	//		Builds a regular expression that groups subexpressions
	//	description:
	//		A utility function used by some of the RE generators. The
	//		subexpressions are constructed by the function, re, in the second
	//		parameter.  re builds one subexpression for each elem in the array
	//		a, in the first parameter. Returns a string for a regular
	//		expression that groups all the subexpressions.
	// arr:
	//		A single value or an array of values.
	// re:
	//		A function. Takes one parameter and converts it to a regular
	//		expression. 
	// nonCapture:
	//		If true, uses non-capturing match, otherwise matches are retained
	//		by regular expression. Defaults to false

	// case 1: a is a single value.
	if(!(arr instanceof Array)){
		return re(arr); // String
	}

	// case 2: a is an array
	var b = [];
	for(var i = 0; i < arr.length; i++){
		// convert each elem to a RE
		b.push(re(arr[i]));
	}

	 // join the REs as alternatives in a RE group.
	return dojo.regexp.group(b.join("|"), nonCapture); // String
}

dojo.regexp.group = function(/*String*/expression, /*Boolean?*/nonCapture){
	// summary:
	//		adds group match to expression
	// nonCapture:
	//		If true, uses non-capturing match, otherwise matches are retained
	//		by regular expression. 
	return "(" + (nonCapture ? "?:":"") + expression + ")"; // String
}