+++ /dev/null
-/* String streams are the things fed to parsers (which can feed them
- * to a tokenizer if they want). They provide peek and next methods
- * for looking at the current character (next 'consumes' this
- * character, peek does not), and a get method for retrieving all the
- * text that was consumed since the last time get was called.
- *
- * An easy mistake to make is to let a StopIteration exception finish
- * the token stream while there are still characters pending in the
- * string stream (hitting the end of the buffer while parsing a
- * token). To make it easier to detect such errors, the stringstreams
- * throw an exception when this happens.
- */
-
-// Make a stringstream stream out of an iterator that returns strings.
-// This is applied to the result of traverseDOM (see codemirror.js),
-// and the resulting stream is fed to the parser.
-window.stringStream = function(source){
- // String that's currently being iterated over.
- var current = "";
- // Position in that string.
- var pos = 0;
- // Accumulator for strings that have been iterated over but not
- // get()-ed yet.
- var accum = "";
- // Make sure there are more characters ready, or throw
- // StopIteration.
- function ensureChars() {
- while (pos == current.length) {
- accum += current;
- current = ""; // In case source.next() throws
- pos = 0;
- try {current = source.next();}
- catch (e) {
- if (e != StopIteration) throw e;
- else return false;
- }
- }
- return true;
- }
-
- return {
- // Return the next character in the stream.
- peek: function() {
- if (!ensureChars()) return null;
- return current.charAt(pos);
- },
- // Get the next character, throw StopIteration if at end, check
- // for unused content.
- next: function() {
- if (!ensureChars()) {
- if (accum.length > 0)
- throw "End of stringstream reached without emptying buffer ('" + accum + "').";
- else
- throw StopIteration;
- }
- return current.charAt(pos++);
- },
- // Return the characters iterated over since the last call to
- // .get().
- get: function() {
- var temp = accum;
- accum = "";
- if (pos > 0){
- temp += current.slice(0, pos);
- current = current.slice(pos);
- pos = 0;
- }
- return temp;
- },
- // Push a string back into the stream.
- push: function(str) {
- current = current.slice(0, pos) + str + current.slice(pos);
- },
- lookAhead: function(str, consume, skipSpaces, caseInsensitive) {
- function cased(str) {return caseInsensitive ? str.toLowerCase() : str;}
- str = cased(str);
- var found = false;
-
- var _accum = accum, _pos = pos;
- if (skipSpaces) this.nextWhileMatches(/[\s\u00a0]/);
-
- while (true) {
- var end = pos + str.length, left = current.length - pos;
- if (end <= current.length) {
- found = str == cased(current.slice(pos, end));
- pos = end;
- break;
- }
- else if (str.slice(0, left) == cased(current.slice(pos))) {
- accum += current; current = "";
- try {current = source.next();}
- catch (e) {break;}
- pos = 0;
- str = str.slice(left);
- }
- else {
- break;
- }
- }
-
- if (!(found && consume)) {
- current = accum.slice(_accum.length) + current;
- pos = _pos;
- accum = _accum;
- }
-
- return found;
- },
-
- // Utils built on top of the above
- more: function() {
- return this.peek() !== null;
- },
- applies: function(test) {
- var next = this.peek();
- return (next !== null && test(next));
- },
- nextWhile: function(test) {
- var next;
- while ((next = this.peek()) !== null && test(next))
- this.next();
- },
- matches: function(re) {
- var next = this.peek();
- return (next !== null && re.test(next));
- },
- nextWhileMatches: function(re) {
- var next;
- while ((next = this.peek()) !== null && re.test(next))
- this.next();
- },
- equals: function(ch) {
- return ch === this.peek();
- },
- endOfLine: function() {
- var next = this.peek();
- return next == null || next == "\n";
- }
- };
-};