source: Dev/trunk/src/client/util/build/replace.js

define(["./fs"], function(fs){
        var cached = {};

        return function(contents, replacement){
                var encoding = "utf8";
                if(replacement instanceof Array){
                        // replacement is a vector of replacement instructions; maybe the first item is an encoding
                        if(typeof replacement[0]=="string"){
                                encoding = replacement[0];
                                replacement = replacement.slice(1);
                        }
                }else{
                        // replacement is a single replacement [search, replacement, type] triple
                        replacement = [replacement];
                }
                // at this point, encoding has been determined and replacement is a vector of [search, replacement, type] triples

                replacement.forEach(function(item){
                        var
                                searchText = item[0],
                                replacementText = item[1],
                                type = item[2];
                        if(type=="file"){
                                // replacementText gives a filename that holds the replacement text
                                // TODO add type AMD module
                                replacementText = (cached[filename] = cached[filename] || fs.readFileSynch(replacementText, encoding));
                        }
                        if(searchText instanceof RegExp){
                                contents = contents.replace(searchText, replacementText);
                        }else if(typeof searchText=="function"){
                                contents = searchText(contents);
                        }else{
                                // replace all occurences of searchText with replacementText
                                var
                                        searchTextLength = searchText.length,
                                        replacementTextLength = replacementText.length,
                                        start = contents.indexOf(searchText);
                                while(start!=-1){
                                        contents = contents.substring(0, start) + replacementText + contents.substring(start + searchTextLength);
                                        start = contents.indexOf(searchText, start + replacementTextLength);
                                }
                        }
                });
                return contents;
        };
});