hashtbl/index.js

A hashtable library

"use strict";
var _ = require('underscore');
var type = function(){};
var hash = exports.hash = function(k) {
	if(typeof k.hashCode !== "function") {
		if(typeof k === "string") {
			return k;
		} else if(typeof k === "number") {
			return k;
		} else if(k instanceof type) {
			var h = "";
			k.forEach(function(i, v){
				h += hash(i) + hash(v);
			});
			return h;
		} else {
			var h = "";
			for(var i in k){
				h += hash(i) + hash(k[i]);
			}
			return h;
		}
	}
};
var clean = exports.clean = function(obj) {
	var hasprop = Object.prototype.hasOwnProperty;
	var c = Object.create(null);
	for(var k in obj) {
		if(hasprop.call(obj,k)) {
			c[k] = obj[k];
		}
	}
	return c;
};
var equal = exports.equal = function(a, v) {
	if(a instanceof type && v instanceof type) {
		var b = false;
		var ks = [];
		a.forEach(function(k) {
			ks.push(k);
		});
		v.forEach(function(k){
			ks.push(k);
		});
		ks.sort();
		return _.all(_.uniq(ks, true), function(k){
			return equal(a[k], v[k]);
		});
	} else {
		return _.isEqual(a, v);
	}
}
var create = exports.create = function(obj) {
	var self = new type();
	var tbl = {};
	var forEach = self.forEach = function(f) {
		for(var a in tbl) {
			for(var b in tbl[a]) {
				f(tbl[a][b][0], tbl[a][b][1]);
			}	
		}
	};
	var map = self.map = function(f) {
		var acc = [];
		forEach(function(k, v) {
			acc.push(f(k,v));
		});
		return acc;
	};
	var set = self.set = function(k, v) {
		var h = hash(k);
		if(tbl[h]) {
			var res = _.find(tbl[h], function(v) {
				return equal(k, v[0]);
			});
			if(typeof res !== 'undefined'){
				res[0] = k;
				res[1] = v;
			} else {
				tbl[h].push([k,v]);
			}
		} else {
			tbl[h] = [[k, v]];
		}
	};
	var get = self.get = function(k) {
		var buckets = tbl[hash(k)];
		var res = _.find(buckets, function(v) {
			return equal(k, v[0]);
		});
		return res[1];
	};
	self.toString = function() {
		var res = "{";
		var i = 0;
		forEach(function(k, v){
			res += ((i++) ? ", " : "") + k + " : " + v;
		});
		res += "}";
		return res;
	};
	var c = clean(obj);
	for(var k in c) {
		set(k, c[k]);
	}
	return self;
};