A nice little FP container that guarantees type safety.
You simply create the container passing in the datatypes you want to allow and then you can perform operations on it.
const Type = require('./Type');
// Define the allowed types and an incorrect-type handler
const StringNumArr = Type(
[String, Number, Array],
(_) => {
throw new TypeError('Input type is not a valid data type');
},
);
// StringNumArr will only accept the defined types (String | Number | Array)
const typeSafeBox = StringNumArr('olleH');
typeSafeBox
.map((a) => a.split('')) // => Type(o,l,l,e,H)
.map((a) => a.reverse()) // => Type(H,e,l,l,o)
.map((a) => a.concat(' world')) // => Type(H,e,l,l,o, world)
.map((a) => a.join('')) // => Type(Hello world)
.chain((a) => a.toUpperCase()); // => 'HELLO WORLD'Notice that if we perform the same map functions but do not allow the Array datatype we get an error:
const StringNumArr = Type(
[String, Number],
(_) => {
throw new TypeError('Input type is not a valid data type');
},
);
const typeSafeBox = StringNumArr('olleH');
typeSafeBox
.map((a) => a.split(''))
.map((a) => a.reverse())
.map((a) => a.concat(' world'))
.map((a) => a.join(''))
.chain((a) => a.toUpperCase());
// => TypeError: Input type is not a valid data type| method | description | example | output |
|---|---|---|---|
map |
takes a function and returns a new container with the result of passing the data through the function | type(5).map((data) => data + 1) |
type(6) |
chain |
the same as map but returns the unwrapped data |
type(5).chain((data) => data + 1) |
6 |
join |
returns the unwrapped data | type(5).join() |
5 |
inspect |
displays the container value when passed to console.log |
console.log(type(5)) |
Type(5) |
MIT Licensed. Use all you like at your own risky fun. Go nuts.
Happy coding λ