fp-match v0.1.0

FP-Match

A functional programming pattern matching implementation.

Example

import match from "fp-match";

var target = { foo: "Hello", bar: "World" };

match(target)
    .case({ foo: "hello" }, () => {
        console.log("match case 1");
    })
    .case({ foo: "Hello", bar: "world" }, () => {
        console.lo("match case 2");
    })
    .case({ foo: "hello", bar: "World" }, () => {
        console.log("match case 3")
    })
    .case({ foo: "Hello" }, () => { // this case wll be matched instead
        console.log("match case 4");
    })
    .case({ foo: "Hello", bar: "World" }, () => {
        console.log("match case 5");
    });

API

• match(target: any): MatchContext Creates a match context.
• MatchContext.prototype.case(value: any, callback: (value: any) => void): this Tries to test a value and call the corresponding callback function. Many cases may be set, but only the first matched one will be called.
  • value If the input target is a primitive value, will check if the input value strictly equals the target. Also, the value could be a function that returns a boolean value indicates whether pass the check. If the input target is an object value, will check if the input value partially matches the target. However, if a function is passed, other than returning boolean, it can return an object that partially matches the input target as well. In either case. the function accepts an argument, which is the input target.
  • callback If check passed, the callback function will be called and the input target will be passed as the argument.
• MatchContext.prototype.default(callback: (value: any) => void): void If none of the cases is matched, the default callback will be called.
• MatchContext.prototype.test(value: any): boolean Tests if the given value matches the input target.

Matches Any Value

This module exports a special symbol any indicates matching any value of the input target (except undefined).

import { match, any } from "fp-match";

var target = { foo: "Hello", bar: "World" };

match(target)
    .case({ foo: "Hello", bar: any }, () => {
        // ...
    });

For more examples, see test.