keyword-args v1.0.0

keyword-args

Python style keyword arguments with thorough typescript typing inference.

Examples

A trivial example:

import { kwargs, KwsParameters, extractKwargs } from 'keyword-args';

function add(...args: KwsParameters<[a: number, b: number], { type: 'number' }>): number;
function add(...args: KwsParameters<[a: number, b: number], { type: 'string' }>): string;
function add(
    ...args: KwsParameters<[a: string | number, b: string | number], { type: 'number' | 'string' }>
): number | string {
    const [[a, b], { type }] = extractKwargs(args, { type: 'number' });
    if (type === 'number') return +a + +b;
    return `${a}${b}`;
}

const a = add(1, 2, { type: 'number' })     // type: number
const b = add('1', '2', { type: 'string' }) // type: string

Spread arguments:

function python_print(
    ...args: SpreadKwsParameters<
        string[],
        { sep?: string; end?: string }
    >): void {
    const [strs, { sep, end }] = extractKwargs(args, { sep: ' ', end: '\n' });
    console.log(strs.join(sep) + end);
}

python_print('hello', 'world', kwargs({ sep: '\n', end: '' }));
// hello
// world

TODO

• Typing for default kwargs
• Unify SpreadKwsParameters and KwsParameters
• Tests
• More examples