dojo.provide("dojo.regexp");
dojo.getObject("dojo.regexp.us", true);	// this file also defines stuff in the dojo.regexp.us module (TODO: move to separate file?)
dojo.require("dojo.string.extras");

// *** Regular Expression Generators ***

dojo.regexp.tld = function(/*Object?*/flags){
	// summary: Builds a RE that matches a top-level domain
	//
	// flags:
	//    flags.allowCC  Include 2 letter country code domains.  Default is true.
	//    flags.allowGeneric  Include the generic domains.  Default is true.
	//    flags.allowInfra  Include infrastructure domains.  Default is true.

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.allowCC != "boolean"){ flags.allowCC = true; }
	if(typeof flags.allowInfra != "boolean"){ flags.allowInfra = true; }
	if(typeof flags.allowGeneric != "boolean"){ flags.allowGeneric = true; }

	// Infrastructure top-level domain - only one at present
	var infraRE = "arpa";

	// Generic top-level domains RE.
	var genericRE = 
		"aero|biz|com|coop|edu|gov|info|int|mil|museum|name|net|org|pro|travel|xxx|jobs|mobi|post";
	
	// Country Code top-level domains RE
	var ccRE = 
		"ac|ad|ae|af|ag|ai|al|am|an|ao|aq|ar|as|at|au|aw|az|ba|bb|bd|be|bf|bg|bh|bi|bj|bm|bn|bo|br|" +
		"bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|cr|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|" +
		"ec|ee|eg|er|eu|es|et|fi|fj|fk|fm|fo|fr|ga|gd|ge|gf|gg|gh|gi|gl|gm|gn|gp|gq|gr|gs|gt|gu|gw|"
		+
		"gy|hk|hm|hn|hr|ht|hu|id|ie|il|im|in|io|ir|is|it|je|jm|jo|jp|ke|kg|kh|ki|km|kn|kr|kw|ky|kz|" +
		"la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|mg|mh|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|mv|mw|mx|" +
		"my|mz|na|nc|ne|nf|ng|ni|nl|no|np|nr|nu|nz|om|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|ps|pt|pw|py|qa|" +
		"re|ro|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sk|sl|sm|sn|sr|st|su|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tm|" +
		"tn|to|tr|tt|tv|tw|tz|ua|ug|uk|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw";

	// Build top-level domain RE
	var a = [];
	if(flags.allowInfra){ a.push(infraRE); }
	if(flags.allowGeneric){ a.push(genericRE); }
	if(flags.allowCC){ a.push(ccRE); }

	var tldRE = "";
	if (a.length > 0) {
		tldRE = "(" + a.join("|") + ")";
	}

	return tldRE; // String
}

dojo.regexp.ipAddress = function(/*Object?*/flags){
	// summary: Builds a RE that matches an IP Address
	//
	// description:
	//  Supports 5 formats for IPv4: dotted decimal, dotted hex, dotted octal, decimal and hexadecimal.
	//  Supports 2 formats for Ipv6.
	//
	// flags  An object.  All flags are boolean with default = true.
	//    flags.allowDottedDecimal  Example, 207.142.131.235.  No zero padding.
	//    flags.allowDottedHex  Example, 0x18.0x11.0x9b.0x28.  Case insensitive.  Zero padding allowed.
	//    flags.allowDottedOctal  Example, 0030.0021.0233.0050.  Zero padding allowed.
	//    flags.allowDecimal  Example, 3482223595.  A decimal number between 0-4294967295.
	//    flags.allowHex  Example, 0xCF8E83EB.  Hexadecimal number between 0x0-0xFFFFFFFF.
	//      Case insensitive.  Zero padding allowed.
	//    flags.allowIPv6   IPv6 address written as eight groups of four hexadecimal digits.
	//    flags.allowHybrid   IPv6 address written as six groups of four hexadecimal digits
	//      followed by the usual 4 dotted decimal digit notation of IPv4. x:x:x:x:x:x:d.d.d.d

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.allowDottedDecimal != "boolean"){ flags.allowDottedDecimal = true; }
	if(typeof flags.allowDottedHex != "boolean"){ flags.allowDottedHex = true; }
	if(typeof flags.allowDottedOctal != "boolean"){ flags.allowDottedOctal = true; }
	if(typeof flags.allowDecimal != "boolean"){ flags.allowDecimal = true; }
	if(typeof flags.allowHex != "boolean"){ flags.allowHex = true; }
	if(typeof flags.allowIPv6 != "boolean"){ flags.allowIPv6 = true; }
	if(typeof flags.allowHybrid != "boolean"){ flags.allowHybrid = true; }

	// decimal-dotted IP address RE.
	var dottedDecimalRE = 
		// Each number is between 0-255.  Zero padding is not allowed.
		"((\\d|[1-9]\\d|1\\d\\d|2[0-4]\\d|25[0-5])\\.){3}(\\d|[1-9]\\d|1\\d\\d|2[0-4]\\d|25[0-5])";

	// dotted hex IP address RE.  Each number is between 0x0-0xff.  Zero padding is allowed, e.g. 0x00.
	var dottedHexRE = "(0[xX]0*[\\da-fA-F]?[\\da-fA-F]\\.){3}0[xX]0*[\\da-fA-F]?[\\da-fA-F]";

	// dotted octal IP address RE.  Each number is between 0000-0377.  
	// Zero padding is allowed, but each number must have at least 4 characters.
	var dottedOctalRE = "(0+[0-3][0-7][0-7]\\.){3}0+[0-3][0-7][0-7]";

	// decimal IP address RE.  A decimal number between 0-4294967295.  
	var decimalRE =  "(0|[1-9]\\d{0,8}|[1-3]\\d{9}|4[01]\\d{8}|42[0-8]\\d{7}|429[0-3]\\d{6}|" +
		"4294[0-8]\\d{5}|42949[0-5]\\d{4}|429496[0-6]\\d{3}|4294967[01]\\d{2}|42949672[0-8]\\d|429496729[0-5])";

	// hexadecimal IP address RE. 
	// A hexadecimal number between 0x0-0xFFFFFFFF. Case insensitive.  Zero padding is allowed.
	var hexRE = "0[xX]0*[\\da-fA-F]{1,8}";

	// IPv6 address RE. 
	// The format is written as eight groups of four hexadecimal digits, x:x:x:x:x:x:x:x,
	// where x is between 0000-ffff. Zero padding is optional. Case insensitive. 
	var ipv6RE = "([\\da-fA-F]{1,4}\\:){7}[\\da-fA-F]{1,4}";

	// IPv6/IPv4 Hybrid address RE. 
	// The format is written as six groups of four hexadecimal digits, 
	// followed by the 4 dotted decimal IPv4 format. x:x:x:x:x:x:d.d.d.d
	var hybridRE = "([\\da-fA-F]{1,4}\\:){6}" + 
		"((\\d|[1-9]\\d|1\\d\\d|2[0-4]\\d|25[0-5])\\.){3}(\\d|[1-9]\\d|1\\d\\d|2[0-4]\\d|25[0-5])";

	// Build IP Address RE
	var a = [];
	if(flags.allowDottedDecimal){ a.push(dottedDecimalRE); }
	if(flags.allowDottedHex){ a.push(dottedHexRE); }
	if(flags.allowDottedOctal){ a.push(dottedOctalRE); }
	if(flags.allowDecimal){ a.push(decimalRE); }
	if(flags.allowHex){ a.push(hexRE); }
	if(flags.allowIPv6){ a.push(ipv6RE); }
	if(flags.allowHybrid){ a.push(hybridRE); }

	var ipAddressRE = "";
	if(a.length > 0){
		ipAddressRE = "(" + a.join("|") + ")";
	}

	return ipAddressRE; // String
}

dojo.regexp.host = function(/*Object?*/flags){
	// summary: Builds a RE that matches a host
	// description: A host is a domain name or an IP address, possibly followed by a port number.
	// flags: An object.
	//    flags.allowIP  Allow an IP address for hostname.  Default is true.
	//    flags.allowLocal  Allow the host to be "localhost".  Default is false.
	//    flags.allowPort  Allow a port number to be present.  Default is true.
	//    flags in regexp.ipAddress can be applied.
	//    flags in regexp.tld can be applied.

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.allowIP != "boolean"){ flags.allowIP = true; }
	if(typeof flags.allowLocal != "boolean"){ flags.allowLocal = false; }
	if(typeof flags.allowPort != "boolean"){ flags.allowPort = true; }

	// Domain names can not end with a dash.
	var domainNameRE = "([0-9a-zA-Z]([-0-9a-zA-Z]{0,61}[0-9a-zA-Z])?\\.)+" + dojo.regexp.tld(flags);

	// port number RE
	var portRE = ( flags.allowPort ) ? "(\\:" + dojo.regexp.integer({signed: false}) + ")?" : "";

	// build host RE
	var hostNameRE = domainNameRE;
	if(flags.allowIP){ hostNameRE += "|" +  dojo.regexp.ipAddress(flags); }
	if(flags.allowLocal){ hostNameRE += "|localhost"; }

	return "(" + hostNameRE + ")" + portRE; // String
}

dojo.regexp.url = function(/*Object?*/flags){
	// summary: Builds a regular expression that matches a URL
	//
	// flags: An object
	//    flags.scheme  Can be true, false, or [true, false]. 
	//      This means: required, not allowed, or match either one.
	//    flags in regexp.host can be applied.
	//    flags in regexp.ipAddress can be applied.
	//    flags in regexp.tld can be applied.

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.scheme == "undefined"){ flags.scheme = [true, false]; }

	// Scheme RE
	var protocolRE = dojo.regexp.buildGroupRE(flags.scheme,
		function(q){ if(q){ return "(https?|ftps?)\\://"; } return ""; }
	);

	// Path and query and anchor RE
	var pathRE = "(/([^?#\\s/]+/)*)?([^?#\\s/]+(\\?[^?#\\s/]*)?(#[A-Za-z][\\w.:-]*)?)?";

	return protocolRE + dojo.regexp.host(flags) + pathRE;
}

dojo.regexp.emailAddress = function(/*Object?*/flags){

	// summary: Builds a regular expression that matches an email address
	//
	//flags: An object
	//    flags.allowCruft  Allow address like <mailto:foo@yahoo.com>.  Default is false.
	//    flags in regexp.host can be applied.
	//    flags in regexp.ipAddress can be applied.
	//    flags in regexp.tld can be applied.

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if (typeof flags.allowCruft != "boolean") { flags.allowCruft = false; }
	flags.allowPort = false; // invalid in email addresses

	// user name RE - apostrophes are valid if there's not 2 in a row
	var usernameRE = "([\\da-z]+[-._+&'])*[\\da-z]+";

	// build emailAddress RE
	var emailAddressRE = usernameRE + "@" + dojo.regexp.host(flags);

	// Allow email addresses with cruft
	if ( flags.allowCruft ) {
		emailAddressRE = "<?(mailto\\:)?" + emailAddressRE + ">?";
	}

	return emailAddressRE; // String
}

dojo.regexp.emailAddressList = function(/*Object?*/flags){
	// summary: Builds a regular expression that matches a list of email addresses.
	//
	// flags: An object.
	//    flags.listSeparator  The character used to separate email addresses.  Default is ";", ",", "\n" or " ".
	//    flags in regexp.emailAddress can be applied.
	//    flags in regexp.host can be applied.
	//    flags in regexp.ipAddress can be applied.
	//    flags in regexp.tld can be applied.

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.listSeparator != "string"){ flags.listSeparator = "\\s;,"; }

	// build a RE for an Email Address List
	var emailAddressRE = dojo.regexp.emailAddress(flags);
	var emailAddressListRE = "(" + emailAddressRE + "\\s*[" + flags.listSeparator + "]\\s*)*" + 
		emailAddressRE + "\\s*[" + flags.listSeparator + "]?\\s*";

	return emailAddressListRE; // String
}

dojo.regexp.integer = function(/*Object?*/flags){
	// summary: Builds a regular expression that matches an integer
	//
	// flags: An object
	//    flags.signed  The leading plus-or-minus sign.  Can be true, false, or [true, false].
	//      Default is [true, false], (i.e. will match if it is signed or unsigned).
	//    flags.separator  The character used as the thousands separator.  Default is no separator.
	//      For more than one symbol use an array, e.g. [",", ""], makes ',' optional.
	//	flags.groupSize group size between separators
	//	flags.groupSize2 second grouping (for India)

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.signed == "undefined"){ flags.signed = [true, false]; }
	if(typeof flags.separator == "undefined"){
		flags.separator = "";
	} else if(typeof flags.groupSize == "undefined"){
		flags.groupSize = 3;
	}
	// build sign RE
	var signRE = dojo.regexp.buildGroupRE(flags.signed,
		function(q) { return q ? "[-+]" : ""; },
		true
	);

	// number RE
	var numberRE = dojo.regexp.buildGroupRE(flags.separator,
		function(sep){ 
			if(!sep){ 
				return "(?:0|[1-9]\\d*)";
			}
			var grp = flags.groupSize, grp2 = flags.groupSize2;
			if(grp2){
				var grp2RE = "(?:0|[1-9]\\d{0," + (grp2-1) + "}(?:[" + sep + "]\\d{" + grp2 + "})*[" + sep + "]\\d{" + grp + "})";
				return ((grp-grp2) > 0) ? "(?:" + grp2RE + "|(?:0|[1-9]\\d{0," + (grp-1) + "}))" : grp2RE;
			}
			return "(?:0|[1-9]\\d{0," + (grp-1) + "}(?:[" + sep + "]\\d{" + grp + "})*)";
		},
		true
	);

	// integer RE
	return signRE + numberRE; // String
}

dojo.regexp.realNumber = function(/*Object?*/flags){
	// summary: Builds a regular expression to match a real number in exponential notation
	//
	// flags:An object
	//    flags.places  The integer number of decimal places or a range given as "n,m"
	//      If not given, the decimal part is optional and the number of places is unlimited.
	//    flags.decimal  A string for the character used as the decimal point.  Default is ".".
	//    flags.fractional  Whether decimal places are allowed.
	//      Can be true, false, or [true, false].  Default is [true, false]
	//    flags.exponent  Express in exponential notation.  Can be true, false, or [true, false].
	//      Default is [true, false], (i.e. will match if the exponential part is present are not).
	//    flags.eSigned  The leading plus-or-minus sign on the exponent.  Can be true, false, 
	//      or [true, false].  Default is [true, false], (i.e. will match if it is signed or unsigned).
	//    flags in regexp.integer can be applied.

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.places == "undefined"){ flags.places = Infinity; }
	if(typeof flags.decimal != "string"){ flags.decimal = "."; }
	if(typeof flags.fractional == "undefined"){ flags.fractional = [true, false]; }
	if(typeof flags.exponent == "undefined"){ flags.exponent = [true, false]; }
	if(typeof flags.eSigned == "undefined"){ flags.eSigned = [true, false]; }

	// integer RE
	var integerRE = dojo.regexp.integer(flags);

	// decimal RE
	var decimalRE = dojo.regexp.buildGroupRE(flags.fractional,
		function(q){
			var re = "";
			if(q && (flags.places!==0)){
				re = "\\" + flags.decimal;
				if(flags.places == Infinity){ 
					re = "(?:" + re + "\\d+)?"; 
				}else{
					re += "\\d{" + flags.places + "}"; 
				}
			}
			return re;
		},
		true
	);

	// exponent RE
	var exponentRE = dojo.regexp.buildGroupRE(flags.exponent,
		function(q){ 
			if(q){ return "([eE]" + dojo.regexp.integer({ signed: flags.eSigned}) + ")"; }
			return ""; 
		}
	);

	// real number RE
	var realRE = integerRE + decimalRE;
	// allow for decimals without integers, e.g. .25
	if(decimalRE){realRE = "(?:(?:"+ realRE + ")|(?:" + decimalRE + "))";}
	return realRE + exponentRE; // String
}

dojo.regexp.currency = function(/*Object?*/flags){
	// summary: Builds a regular expression to match a monetary value
	//
	// flags: An object
	//    flags.symbol  A currency symbol such as Yen "�", Pound "�", or the Euro sign "�".  
	//      Default is "$".  For more than one symbol use an array, e.g. ["$", ""], makes $ optional.
	//    flags.placement  The symbol can come "before" the number or "after" the number.  Default is "before".
	//    flags.signPlacement  The sign can come "before" the number or "after" the sign,
	//      "around" to put parentheses around negative values, or "end" for the final char.  Default is "before".
	//    flags in regexp.realNumber can be applied except exponent, eSigned.

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.signed == "undefined"){ flags.signed = [true, false]; }
	if(typeof flags.symbol == "undefined"){ flags.symbol = "$"; }
	if(typeof flags.placement != "string"){ flags.placement = "before"; }
	if(typeof flags.signPlacement != "string"){ flags.signPlacement = "before"; }
	if(typeof flags.separator == "undefined"){ flags.separator = ","; }
	if(typeof flags.decimal != "string"){ flags.decimal = "."; }

	// build sign RE
	var signRE = dojo.regexp.buildGroupRE(flags.signed,
		function(q){ if (q){ return "[-+]"; } return ""; }
	);

	// build symbol RE
	var symbolRE = dojo.regexp.buildGroupRE(flags.symbol,
		function(symbol){ 
			// escape all special characters
			return "\\s?" + symbol.replace( /([.$?*!=:|\\\/^])/g, "\\$1") + "\\s?";
		}
	);

	switch (flags.signPlacement){
		case "before":
			symbolRE = signRE + symbolRE;
			break;
		case "after":
			symbolRE = symbolRE + signRE;
			break;
	}

	// number RE
	var flagsCopy = flags; //TODO: copy by value?
	flagsCopy.signed = false; flagsCopy.exponent = false;
	var numberRE = dojo.regexp.realNumber(flagsCopy);

	// build currency RE
	var currencyRE;
	switch (flags.placement){
		case "before":
			currencyRE = symbolRE + numberRE;
			break;
		case "after":
			currencyRE = numberRE + symbolRE;
			break;
	}

	switch (flags.signPlacement){
		case "around":
			currencyRE = "(" + currencyRE + "|" + "\\(" + currencyRE + "\\)" + ")";
			break;
		case "begin":
			currencyRE = signRE + currencyRE;
			break;
		case "end":
			currencyRE = currencyRE + signRE;
			break;
	}
	return currencyRE; // String
}


dojo.regexp.us.state = function(/*Object?*/flags){
	// summary: A regular expression to match US state and territory abbreviations
	//
	// flags  An object.
	//    flags.allowTerritories  Allow Guam, Puerto Rico, etc.  Default is true.
	//    flags.allowMilitary  Allow military 'states', e.g. Armed Forces Europe (AE).  Default is true.

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.allowTerritories != "boolean"){ flags.allowTerritories = true; }
	if(typeof flags.allowMilitary != "boolean"){ flags.allowMilitary = true; }

	// state RE
	var statesRE = 
		"AL|AK|AZ|AR|CA|CO|CT|DE|DC|FL|GA|HI|ID|IL|IN|IA|KS|KY|LA|ME|MD|MA|MI|MN|MS|MO|MT|" + 
		"NE|NV|NH|NJ|NM|NY|NC|ND|OH|OK|OR|PA|RI|SC|SD|TN|TX|UT|VT|VA|WA|WV|WI|WY";

	// territories RE
	var territoriesRE = "AS|FM|GU|MH|MP|PW|PR|VI";

	// military states RE
	var militaryRE = "AA|AE|AP";

	// Build states and territories RE
	if(flags.allowTerritories){ statesRE += "|" + territoriesRE; }
	if(flags.allowMilitary){ statesRE += "|" + militaryRE; }

	return "(" + statesRE + ")"; // String
}

dojo.regexp.time = function(/*Object?*/flags){
	// summary: Builds a regular expression to match any International format for time
	// description: The RE can match one format or one of multiple formats.
	//
	//  Format
	//  h        12 hour, no zero padding.
	//  hh       12 hour, has leading zero.
	//  H        24 hour, no zero padding.
	//  HH       24 hour, has leading zero.
	//  m        minutes, no zero padding.
	//  mm       minutes, has leading zero.
	//  s        seconds, no zero padding.
	//  ss       seconds, has leading zero.
	//  t        am or pm, case insensitive.
	//  All other characters must appear literally in the expression.
	//
	//  Example
	//    "h:m:s t"  ->   2:5:33 PM
	//    "HH:mm:ss" ->  14:05:33
	//
	// flags: An object
	//    flags.format  A string or an array of strings.  Default is "h:mm:ss t".
	//    flags.amSymbol  The symbol used for AM.  Default is "AM".
	//    flags.pmSymbol  The symbol used for PM.  Default is "PM".

	dojo.deprecated("dojo.regexp.time", "Use dojo.date.parse instead", "0.5");

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.format == "undefined"){ flags.format = "h:mm:ss t"; }
	if(typeof flags.amSymbol != "string"){ flags.amSymbol = "AM"; }
	if(typeof flags.pmSymbol != "string"){ flags.pmSymbol = "PM"; }

	// Converts a time format to a RE
	var timeRE = function(format){
		// escape all special characters
		format = format.replace( /([.$?*!=:|{}\(\)\[\]\\\/^])/g, "\\$1");
		var amRE = flags.amSymbol.replace( /([.$?*!=:|{}\(\)\[\]\\\/^])/g, "\\$1");
		var pmRE = flags.pmSymbol.replace( /([.$?*!=:|{}\(\)\[\]\\\/^])/g, "\\$1");

		// replace tokens with Regular Expressions
		format = format.replace("hh", "(0[1-9]|1[0-2])");
		format = format.replace("h", "([1-9]|1[0-2])");
		format = format.replace("HH", "([01][0-9]|2[0-3])");
		format = format.replace("H", "([0-9]|1[0-9]|2[0-3])");
		format = format.replace("mm", "([0-5][0-9])");
		format = format.replace("m", "([1-5][0-9]|[0-9])");
		format = format.replace("ss", "([0-5][0-9])");
		format = format.replace("s", "([1-5][0-9]|[0-9])");
		format = format.replace("t", "\\s?(" + amRE + "|" + pmRE + ")\\s?" );

		return format; // String
	};

	// build RE for multiple time formats
	return dojo.regexp.buildGroupRE(flags.format, timeRE); // String
}

dojo.regexp.numberFormat = function(/*Object?*/flags){
	// summary: Builds a regular expression to match any sort of number based format
	// description:
	//  Use this method for phone numbers, social security numbers, zip-codes, etc.
	//  The RE can match one format or one of multiple formats.
	//
	//  Format
	//    #        Stands for a digit, 0-9.
	//    ?        Stands for an optional digit, 0-9 or nothing.
	//    All other characters must appear literally in the expression.
	//
	//  Example   
	//    "(###) ###-####"       ->   (510) 542-9742
	//    "(###) ###-#### x#???" ->   (510) 542-9742 x153
	//    "###-##-####"          ->   506-82-1089       i.e. social security number
	//    "#####-####"           ->   98225-1649        i.e. zip code
	//
	// flags:  An object
	//    flags.format  A string or an Array of strings for multiple formats.

	// assign default values to missing paramters
	flags = (typeof flags == "object") ? flags : {};
	if(typeof flags.format == "undefined"){ flags.format = "###-###-####"; }

	// Converts a number format to RE.
	var digitRE = function(format){
		// escape all special characters, except '?'
		format = dojo.string.escapeRegExp(format, "?");

		// Now replace '?' with Regular Expression
		format = format.replace(/\?/g, "\\d?");

		// replace # with Regular Expression
		format = format.replace(/#/g, "\\d");

		return format; // String
	};

	// build RE for multiple number formats
	return dojo.regexp.buildGroupRE(flags.format, digitRE); //String
}


dojo.regexp.buildGroupRE = function(/*value or Array of values*/a, /*Function(x) returns a regular expression as a String*/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.
	//
	// a:  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. 

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

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