--- /dev/null
+var util = require('./util');
+var types = require('./types');
+var sets = require('./sets');
+var positions = require('./positions');
+
+
+module.exports = function(regexpStr) {
+ var i = 0, l, c,
+ start = { type: types.ROOT, stack: []},
+
+ // Keep track of last clause/group and stack.
+ lastGroup = start,
+ last = start.stack,
+ groupStack = [];
+
+
+ var repeatErr = function(i) {
+ util.error(regexpStr, 'Nothing to repeat at column ' + (i - 1));
+ };
+
+ // Decode a few escaped characters.
+ var str = util.strToChars(regexpStr);
+ l = str.length;
+
+ // Iterate through each character in string.
+ while (i < l) {
+ c = str[i++];
+
+ switch (c) {
+ // Handle escaped characters, inclues a few sets.
+ case '\\':
+ c = str[i++];
+
+ switch (c) {
+ case 'b':
+ last.push(positions.wordBoundary());
+ break;
+
+ case 'B':
+ last.push(positions.nonWordBoundary());
+ break;
+
+ case 'w':
+ last.push(sets.words());
+ break;
+
+ case 'W':
+ last.push(sets.notWords());
+ break;
+
+ case 'd':
+ last.push(sets.ints());
+ break;
+
+ case 'D':
+ last.push(sets.notInts());
+ break;
+
+ case 's':
+ last.push(sets.whitespace());
+ break;
+
+ case 'S':
+ last.push(sets.notWhitespace());
+ break;
+
+ default:
+ // Check if c is integer.
+ // In which case it's a reference.
+ if (/\d/.test(c)) {
+ last.push({ type: types.REFERENCE, value: parseInt(c, 10) });
+
+ // Escaped character.
+ } else {
+ last.push({ type: types.CHAR, value: c.charCodeAt(0) });
+ }
+ }
+
+ break;
+
+
+ // Positionals.
+ case '^':
+ last.push(positions.begin());
+ break;
+
+ case '$':
+ last.push(positions.end());
+ break;
+
+
+ // Handle custom sets.
+ case '[':
+ // Check if this class is 'anti' i.e. [^abc].
+ var not;
+ if (str[i] === '^') {
+ not = true;
+ i++;
+ } else {
+ not = false;
+ }
+
+ // Get all the characters in class.
+ var classTokens = util.tokenizeClass(str.slice(i), regexpStr);
+
+ // Increase index by length of class.
+ i += classTokens[1];
+ last.push({
+ type: types.SET,
+ set: classTokens[0],
+ not: not,
+ });
+
+ break;
+
+
+ // Class of any character except \n.
+ case '.':
+ last.push(sets.anyChar());
+ break;
+
+
+ // Push group onto stack.
+ case '(':
+ // Create group.
+ var group = {
+ type: types.GROUP,
+ stack: [],
+ remember: true,
+ };
+
+ c = str[i];
+
+ // If if this is a special kind of group.
+ if (c === '?') {
+ c = str[i + 1];
+ i += 2;
+
+ // Match if followed by.
+ if (c === '=') {
+ group.followedBy = true;
+
+ // Match if not followed by.
+ } else if (c === '!') {
+ group.notFollowedBy = true;
+
+ } else if (c !== ':') {
+ util.error(regexpStr,
+ 'Invalid group, character \'' + c +
+ '\' after \'?\' at column ' + (i - 1));
+ }
+
+ group.remember = false;
+ }
+
+ // Insert subgroup into current group stack.
+ last.push(group);
+
+ // Remember the current group for when the group closes.
+ groupStack.push(lastGroup);
+
+ // Make this new group the current group.
+ lastGroup = group;
+ last = group.stack;
+ break;
+
+
+ // Pop group out of stack.
+ case ')':
+ if (groupStack.length === 0) {
+ util.error(regexpStr, 'Unmatched ) at column ' + (i - 1));
+ }
+ lastGroup = groupStack.pop();
+
+ // Check if this group has a PIPE.
+ // To get back the correct last stack.
+ last = lastGroup.options ?
+ lastGroup.options[lastGroup.options.length - 1] : lastGroup.stack;
+ break;
+
+
+ // Use pipe character to give more choices.
+ case '|':
+ // Create array where options are if this is the first PIPE
+ // in this clause.
+ if (!lastGroup.options) {
+ lastGroup.options = [lastGroup.stack];
+ delete lastGroup.stack;
+ }
+
+ // Create a new stack and add to options for rest of clause.
+ var stack = [];
+ lastGroup.options.push(stack);
+ last = stack;
+ break;
+
+
+ // Repetition.
+ // For every repetition, remove last element from last stack
+ // then insert back a RANGE object.
+ // This design is chosen because there could be more than
+ // one repetition symbols in a regex i.e. `a?+{2,3}`.
+ case '{':
+ var rs = /^(\d+)(,(\d+)?)?\}/.exec(str.slice(i)), min, max;
+ if (rs !== null) {
+ if (last.length === 0) {
+ repeatErr(i);
+ }
+ min = parseInt(rs[1], 10);
+ max = rs[2] ? rs[3] ? parseInt(rs[3], 10) : Infinity : min;
+ i += rs[0].length;
+
+ last.push({
+ type: types.REPETITION,
+ min: min,
+ max: max,
+ value: last.pop(),
+ });
+ } else {
+ last.push({
+ type: types.CHAR,
+ value: 123,
+ });
+ }
+ break;
+
+ case '?':
+ if (last.length === 0) {
+ repeatErr(i);
+ }
+ last.push({
+ type: types.REPETITION,
+ min: 0,
+ max: 1,
+ value: last.pop(),
+ });
+ break;
+
+ case '+':
+ if (last.length === 0) {
+ repeatErr(i);
+ }
+ last.push({
+ type: types.REPETITION,
+ min: 1,
+ max: Infinity,
+ value: last.pop(),
+ });
+ break;
+
+ case '*':
+ if (last.length === 0) {
+ repeatErr(i);
+ }
+ last.push({
+ type: types.REPETITION,
+ min: 0,
+ max: Infinity,
+ value: last.pop(),
+ });
+ break;
+
+
+ // Default is a character that is not `\[](){}?+*^$`.
+ default:
+ last.push({
+ type: types.CHAR,
+ value: c.charCodeAt(0),
+ });
+ }
+
+ }
+
+ // Check if any groups have not been closed.
+ if (groupStack.length !== 0) {
+ util.error(regexpStr, 'Unterminated group');
+ }
+
+ return start;
+};
+
+module.exports.types = types;
projects / dotfiles / .git / blobdiff