type-comparator
Version:
Useful comparator functions written on Typescript
61 lines • 2.13 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
const interfaces_1 = require("../interfaces");
const mutations_1 = require("../mutations");
const then_chain_1 = require("./then-chain");
const comparators_1 = require("../comparators");
class Chain {
constructor() {
this.mutations = [];
}
reverse() {
this.mutations.push({ type: interfaces_1.MutationType.REVERSE });
return this;
}
map(mapper) {
this.mutations.push({ type: interfaces_1.MutationType.MAP, mapper: mapper });
return this;
}
if(condition) {
this.mutations.push({ type: interfaces_1.MutationType.IF, condition });
return new then_chain_1.ThenChain(this);
}
use(comparatorOrComparators) {
if (Array.isArray(comparatorOrComparators)) {
return (a, b) => {
for (const comparator of comparatorOrComparators) {
const result = this.use(comparator)(a, b);
if (result !== 0) {
return result;
}
}
return 0;
};
}
return Chain.mutate(comparatorOrComparators, this.mutations);
}
asc() {
return this.use(comparators_1.asc);
}
desc() {
return this.use(comparators_1.desc);
}
static mutate(fn, descriptors) {
let currentFn = fn;
for (const descriptor of descriptors.slice().reverse()) {
currentFn = ((prevFn) => {
switch (descriptor.type) {
case interfaces_1.MutationType.REVERSE:
return mutations_1.reverse(prevFn);
case interfaces_1.MutationType.MAP:
return mutations_1.map(descriptor.mapper, prevFn);
case interfaces_1.MutationType.IF:
return mutations_1.condition(descriptor.condition, descriptor.comparator, prevFn);
}
})(currentFn);
}
return currentFn;
}
}
exports.Chain = Chain;
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