lepu-test-platform-web/node_modules/fastparse/lib/Parser.js

109 lines
2.6 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
function ignoreFunction() {}
function createReturningFunction(value) {
return function() {
return value;
};
}
function Parser(states) {
this.states = this.compileStates(states);
}
Parser.prototype.compileStates = function(states) {
var result = {};
Object.keys(states).forEach(function(name) {
result[name] = this.compileState(states[name], states);
}, this);
return result;
};
Parser.prototype.compileState = function(state, states) {
var regExps = [];
function iterator(str, value) {
regExps.push({
groups: Parser.getGroupCount(str),
regExp: str,
value: value
});
}
function processState(statePart) {
if(Array.isArray(statePart)) {
statePart.forEach(processState);
} else if(typeof statePart === "object") {
Object.keys(statePart).forEach(function(key) {
iterator(key, statePart[key]);
});
} else if(typeof statePart === "string") {
processState(states[statePart]);
} else {
throw new Error("Unexpected 'state' format");
}
}
processState(state);
var total = regExps.map(function(r) {
return "(" + r.regExp + ")";
}).join("|");
var actions = [];
var pos = 1;
regExps.forEach(function(r) {
var fn;
if(typeof r.value === "function") {
fn = r.value;
} else if(typeof r.value === "string") {
fn = createReturningFunction(r.value);
} else {
fn = ignoreFunction;
}
actions.push({
name: r.regExp,
fn: fn,
pos: pos,
pos2: pos + r.groups + 1
});
pos += r.groups + 1;
});
return {
regExp: new RegExp(total, "g"),
actions: actions
};
};
Parser.getGroupCount = function(regExpStr) {
return new RegExp("(" + regExpStr + ")|^$").exec("").length - 2;
};
Parser.prototype.parse = function(initialState, string, context) {
context = context || {};
var currentState = initialState;
var currentIndex = 0;
for(;;) {
var state = this.states[currentState];
var regExp = state.regExp;
regExp.lastIndex = currentIndex;
var match = regExp.exec(string);
if(!match) return context;
var actions = state.actions;
currentIndex = state.regExp.lastIndex;
for(var i = 0; i < actions.length; i++) {
var action = actions[i];
if(match[action.pos]) {
var ret = action.fn.apply(context, Array.prototype.slice.call(match, action.pos, action.pos2).concat([state.regExp.lastIndex - match[0].length, match[0].length]));
if(ret) {
if(!(ret in this.states))
throw new Error("State '" + ret + "' doesn't exist");
currentState = ret;
}
break;
}
}
}
};
module.exports = Parser;