hugoWebsite/node_modules/thenby/thenBy.module.js

61 lines
2.3 KiB
JavaScript

/***
Copyright 2013 Teun Duynstee
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
module.exports = (function() {
function identity(v){return v;}
function ignoreCase(v){return typeof(v)==="string" ? v.toLowerCase() : v;}
function makeCompareFunction(f, opt){
opt = typeof(opt)==="object" ? opt : {direction:opt};
if(typeof(f)!="function"){
var prop = f;
// make unary function
f = function(v1){return !!v1[prop] ? v1[prop] : "";}
}
if(f.length === 1) {
// f is a unary function mapping a single item to its sort score
var uf = f;
var preprocess = opt.ignoreCase?ignoreCase:identity;
var cmp = opt.cmp || function(v1,v2) {return v1 < v2 ? -1 : v1 > v2 ? 1 : 0;}
f = function(v1,v2) {return cmp(preprocess(uf(v1)), preprocess(uf(v2)));}
}
const descTokens = {"-1":'', desc:''};
if(opt.direction in descTokens) return function(v1,v2){return -f(v1,v2)};
return f;
}
/* adds a secondary compare function to the target function (`this` context)
which is applied in case the first one returns 0 (equal)
returns a new compare function, which has a `thenBy` method as well */
function tb(func, opt) {
/* should get value false for the first call. This can be done by calling the
exported function, or the firstBy property on it (for es6 module compatibility)
*/
var x = (typeof(this) == "function" && !this.firstBy) ? this : false;
var y = makeCompareFunction(func, opt);
var f = x ? function(a, b) {
return x(a,b) || y(a,b);
}
: y;
f.thenBy = tb;
return f;
}
tb.firstBy = tb;
return tb;
})();