gistfile1.js

parseQuery = function (queryString) {
	
	var literalStrings 			= getLiteralStrings(queryString);
	var strippedString 			= stripLiteralStrings(queryString, literalStrings);
	var booleanExpression 	= getBooleanExpression(strippedString);
	var strippedComparisons = getStrippedComparisons(strippedString);
	var comparisons 				= constructComparisons(strippedComparisons, literalStrings);
	
	return { 	booleanExpression: booleanExpression,
						comparisons: comparisons
				 };

};



getLiteralStrings = function (queryString) {
	
	// this function steps through the input string, recognizes literal strings,
	// remembers their position in the input string and returns an array that
	// contains objects like this:
	// {startPoint: n, endPoint: m, sequenceOfCharacters: s}
	
	var currentlyInString 				= false;
	var delimeterOfCurrentString 	= "";
	var numberOfCurrentString			= 0;
	var isStringDelimeter					= {"'": true, '"': true};
	var isEscapeCharacter					= {"\\": true};
	var currentCharacter 					= "";
	var previousCharacter					= "";
	
	var literalStrings						= [];			//to be returned
	
	// first find the strings start- and end-points:
	
	for (var i=0; i < queryString.length; i++) {
		currentCharacter = queryString[i];
		
		if ( currentlyInString ) {
			if ( currentCharacter == delimeterOfCurrentString 
				&& ! isEscapeCharacter[currentCharacter]  ) {
					
				currentlyInString = false;
				literalStrings[numberOfCurrentString].endPoint = i;
				numberOfCurrentString++;
			};
		}
		else {
			if ( isStringDelimeter[currentCharacter] ) {

				currentlyInString = true;
				delimeterOfCurrentString = currentCharacter;
				literalStrings[numberOfCurrentString] = {startPoint: i};
			};
		};
			
		previousCharacter = currentCharacter;
	};
	
	// then extract the strings:
	
	var s = literalStrings[0];
	for (var i=0; i < literalStrings.length; i++) {
		s = literalStrings[i];
		s.string = queryString.substring(s.startPoint+1, s.endPoint)
	};
	
	return literalStrings;
};

stripLiteralStrings = function (queryString, literalStrings) {
	var strippedString = "";
	return strippedString;
};

getBooleanExpression = function (strippedString) {
	var booleanExpression = "";
	return booleanExpression;
};

getStrippedComparisons = function (strippedString) {
	var strippedComparisons = [];
	return strippedComparisons;
};

constructComparisons = function (strippedComparisons, literalStrings) {
	var comparisons = [];
	return comparisons;
};