js.prompto.runtime.MethodFinder.js Maven / Gradle / Ivy

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var PromptoError = require("../error/PromptoError").PromptoError;
var CategoryType = null;
var Score = require("./Score").Score;

exports.resolve = function() {
	CategoryType = require("../type/CategoryType").CategoryType;
}

function MethodFinder(context, methodCall) {
	this.context = context;
	this.methodCall = methodCall;
	return this;
}

MethodFinder.prototype.findMethod = function(checkInstance) {
	var selector = this.methodCall.method;
	var candidates = selector.getCandidates(this.context, checkInstance);
    if(candidates.length==0)
        this.context.problemListener.reportUnknownMethod(this.methodCall.method.id);
	var compatibles = this.filterCompatible(candidates, checkInstance);
	switch(compatibles.length) {
	case 0:
		this.context.problemListener.reportNoMatchingPrototype(this.methodCall);
	case 1:
		return compatibles[0];
	default:
		return this.findMostSpecific(compatibles, checkInstance);
	}
};

MethodFinder.prototype.findMostSpecific = function(candidates, checkInstance) {
	var candidate = null;
	var ambiguous = [];
	candidates.forEach(function(c) {
		if(candidate==null)
			candidate = c;
		else {
			var score = this.scoreMostSpecific(candidate, c, checkInstance);
			switch(score) {
			case Score.WORSE:
				candidate = c;
				ambiguous = [];
				break;
			case Score.BETTER:
				break;
			case Score.SIMILAR:
				ambiguous.push(c);
				break;
			}
		}
	}, this);
	if(ambiguous.length>0) {
		throw new SyntaxError("Too many prototypes!"); // TODO refine
	}
	return candidate;
}

MethodFinder.prototype.scoreMostSpecific = function(d1, d2, checkInstance) {
	try {
		var s1 = this.context.newLocalContext();
		d1.registerArguments(s1);
		var s2 = this.context.newLocalContext();
		d2.registerArguments(s2);
		var ass1 = this.methodCall.makeAssignments(this.context, d1);
		var ass2 = this.methodCall.makeAssignments(this.context, d2);
		for(var i=0;i