babel/src/lookahead.js

44 lines
752 B
JavaScript

import {Parser} from "./state"
const pp = Parser.prototype
var STATE_KEYS = [
"lastTokStartLoc",
"lastTokEndLoc",
"lastTokStart",
"lastTokEnd",
"lineStart",
"startLoc",
"curLine",
"endLoc",
"start",
"pos",
"end",
"type",
"value",
"exprAllowed",
"potentialArrowAt",
"currLine",
"input"
];
pp.getState = function () {
var state = {}
for (var i = 0; i < STATE_KEYS.length; i++) {
var key = STATE_KEYS[i]
state[key] = this[key]
}
state.context = this.context.slice()
return state
};
pp.lookahead = function() {
var old = this.getState();
this.isLookahead = true
this.next()
this.isLookahead = false
var curr = this.getState();
for (var key in old) this[key] = old[key];
return curr;
};