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- var constants = require('../tokenizer/const');
- var TYPE = constants.TYPE;
- var NAME = constants.NAME;
- var utils = require('../tokenizer/utils');
- var cmpStr = utils.cmpStr;
- var EOF = TYPE.EOF;
- var WHITESPACE = TYPE.WhiteSpace;
- var COMMENT = TYPE.Comment;
- var OFFSET_MASK = 0x00FFFFFF;
- var TYPE_SHIFT = 24;
- var TokenStream = function() {
- this.offsetAndType = null;
- this.balance = null;
- this.reset();
- };
- TokenStream.prototype = {
- reset: function() {
- this.eof = false;
- this.tokenIndex = -1;
- this.tokenType = 0;
- this.tokenStart = this.firstCharOffset;
- this.tokenEnd = this.firstCharOffset;
- },
- lookupType: function(offset) {
- offset += this.tokenIndex;
- if (offset < this.tokenCount) {
- return this.offsetAndType[offset] >> TYPE_SHIFT;
- }
- return EOF;
- },
- lookupOffset: function(offset) {
- offset += this.tokenIndex;
- if (offset < this.tokenCount) {
- return this.offsetAndType[offset - 1] & OFFSET_MASK;
- }
- return this.source.length;
- },
- lookupValue: function(offset, referenceStr) {
- offset += this.tokenIndex;
- if (offset < this.tokenCount) {
- return cmpStr(
- this.source,
- this.offsetAndType[offset - 1] & OFFSET_MASK,
- this.offsetAndType[offset] & OFFSET_MASK,
- referenceStr
- );
- }
- return false;
- },
- getTokenStart: function(tokenIndex) {
- if (tokenIndex === this.tokenIndex) {
- return this.tokenStart;
- }
- if (tokenIndex > 0) {
- return tokenIndex < this.tokenCount
- ? this.offsetAndType[tokenIndex - 1] & OFFSET_MASK
- : this.offsetAndType[this.tokenCount] & OFFSET_MASK;
- }
- return this.firstCharOffset;
- },
- // TODO: -> skipUntilBalanced
- getRawLength: function(startToken, mode) {
- var cursor = startToken;
- var balanceEnd;
- var offset = this.offsetAndType[Math.max(cursor - 1, 0)] & OFFSET_MASK;
- var type;
- loop:
- for (; cursor < this.tokenCount; cursor++) {
- balanceEnd = this.balance[cursor];
- // stop scanning on balance edge that points to offset before start token
- if (balanceEnd < startToken) {
- break loop;
- }
- type = this.offsetAndType[cursor] >> TYPE_SHIFT;
- // check token is stop type
- switch (mode(type, this.source, offset)) {
- case 1:
- break loop;
- case 2:
- cursor++;
- break loop;
- default:
- offset = this.offsetAndType[cursor] & OFFSET_MASK;
- // fast forward to the end of balanced block
- if (this.balance[balanceEnd] === cursor) {
- cursor = balanceEnd;
- }
- }
- }
- return cursor - this.tokenIndex;
- },
- isBalanceEdge: function(pos) {
- return this.balance[this.tokenIndex] < pos;
- },
- isDelim: function(code, offset) {
- if (offset) {
- return (
- this.lookupType(offset) === TYPE.Delim &&
- this.source.charCodeAt(this.lookupOffset(offset)) === code
- );
- }
- return (
- this.tokenType === TYPE.Delim &&
- this.source.charCodeAt(this.tokenStart) === code
- );
- },
- getTokenValue: function() {
- return this.source.substring(this.tokenStart, this.tokenEnd);
- },
- getTokenLength: function() {
- return this.tokenEnd - this.tokenStart;
- },
- substrToCursor: function(start) {
- return this.source.substring(start, this.tokenStart);
- },
- skipWS: function() {
- for (var i = this.tokenIndex, skipTokenCount = 0; i < this.tokenCount; i++, skipTokenCount++) {
- if ((this.offsetAndType[i] >> TYPE_SHIFT) !== WHITESPACE) {
- break;
- }
- }
- if (skipTokenCount > 0) {
- this.skip(skipTokenCount);
- }
- },
- skipSC: function() {
- while (this.tokenType === WHITESPACE || this.tokenType === COMMENT) {
- this.next();
- }
- },
- skip: function(tokenCount) {
- var next = this.tokenIndex + tokenCount;
- if (next < this.tokenCount) {
- this.tokenIndex = next;
- this.tokenStart = this.offsetAndType[next - 1] & OFFSET_MASK;
- next = this.offsetAndType[next];
- this.tokenType = next >> TYPE_SHIFT;
- this.tokenEnd = next & OFFSET_MASK;
- } else {
- this.tokenIndex = this.tokenCount;
- this.next();
- }
- },
- next: function() {
- var next = this.tokenIndex + 1;
- if (next < this.tokenCount) {
- this.tokenIndex = next;
- this.tokenStart = this.tokenEnd;
- next = this.offsetAndType[next];
- this.tokenType = next >> TYPE_SHIFT;
- this.tokenEnd = next & OFFSET_MASK;
- } else {
- this.tokenIndex = this.tokenCount;
- this.eof = true;
- this.tokenType = EOF;
- this.tokenStart = this.tokenEnd = this.source.length;
- }
- },
- dump: function() {
- var offset = this.firstCharOffset;
- return Array.prototype.slice.call(this.offsetAndType, 0, this.tokenCount).map(function(item, idx) {
- var start = offset;
- var end = item & OFFSET_MASK;
- offset = end;
- return {
- idx: idx,
- type: NAME[item >> TYPE_SHIFT],
- chunk: this.source.substring(start, end),
- balance: this.balance[idx]
- };
- }, this);
- }
- };
- module.exports = TokenStream;
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