dfdl

• dfdl(fn, arity?: boolean)
• dfdl(fn, isDataFirst: (args: IArguments) => boolean)

Creates a function that can be used in both data-first and data-last styles. Types are automatically inferred from the input function.

Example

import { dfdl } from "@monstermann/dfdl";

const add = dfdl((a: number, b: number) => a + b);

Data-first

add(1, 2); // 3

Data-last

add(2)(1); // 3
pipe(1, add(2)); // 3

You can explicitly define the function arity if necessary, otherwise fn.length is used:

const add = dfdl(
    (a: number, b: number) => a + b,
    2,
);

And for functions with optional parameters, you can use a custom predicate:

Example

import { dfdl } from "@monstermann/dfdl";

const slice = dfdl(
    (str: string, start: number, end?: number) => str.slice(start, end),
    (args) => typeof args[0] === "string",
);

Data-first

slice("Hello World!", 0, 5); // "Hello"
slice("Hello World!", 6); // "World!"

Data-last

slice(0, 5)("Hello World!"); // "Hello"
slice(6)("Hello World!"); // "World!"