GT2/Ejectable/node_modules/sucrase/dist/parser/tokenizer/readWord.js

65 lines
2.2 KiB
JavaScript

"use strict";Object.defineProperty(exports, "__esModule", {value: true});var _base = require('../traverser/base');
var _charcodes = require('../util/charcodes');
var _identifier = require('../util/identifier');
var _index = require('./index');
var _readWordTree = require('./readWordTree');
var _types = require('./types');
/**
* Read an identifier, producing either a name token or matching on one of the existing keywords.
* For performance, we pre-generate big decision tree that we traverse. Each node represents a
* prefix and has 27 values, where the first value is the token or contextual token, if any (-1 if
* not), and the other 26 values are the transitions to other nodes, or -1 to stop.
*/
function readWord() {
let treePos = 0;
let code = 0;
let pos = _base.state.pos;
while (pos < _base.input.length) {
code = _base.input.charCodeAt(pos);
if (code < _charcodes.charCodes.lowercaseA || code > _charcodes.charCodes.lowercaseZ) {
break;
}
const next = _readWordTree.READ_WORD_TREE[treePos + (code - _charcodes.charCodes.lowercaseA) + 1];
if (next === -1) {
break;
} else {
treePos = next;
pos++;
}
}
const keywordValue = _readWordTree.READ_WORD_TREE[treePos];
if (keywordValue > -1 && !_identifier.IS_IDENTIFIER_CHAR[code]) {
_base.state.pos = pos;
if (keywordValue & 1) {
_index.finishToken.call(void 0, keywordValue >>> 1);
} else {
_index.finishToken.call(void 0, _types.TokenType.name, keywordValue >>> 1);
}
return;
}
while (pos < _base.input.length) {
const ch = _base.input.charCodeAt(pos);
if (_identifier.IS_IDENTIFIER_CHAR[ch]) {
pos++;
} else if (ch === _charcodes.charCodes.backslash) {
// \u
pos += 2;
if (_base.input.charCodeAt(pos) === _charcodes.charCodes.leftCurlyBrace) {
while (pos < _base.input.length && _base.input.charCodeAt(pos) !== _charcodes.charCodes.rightCurlyBrace) {
pos++;
}
pos++;
}
} else if (ch === _charcodes.charCodes.atSign && _base.input.charCodeAt(pos + 1) === _charcodes.charCodes.atSign) {
pos += 2;
} else {
break;
}
}
_base.state.pos = pos;
_index.finishToken.call(void 0, _types.TokenType.name);
} exports.default = readWord;