fp-switch

This is functional switch! This is tiny and curried and also awesome.

Example

import switchCase from 'fp-switch';

switchCase(defaultCase, cases, variable);

if cases[variable] is exist then if it's a function result will be equal cases[variable](variable), if cases[variable] is not function then cases[variable] will be returned as is.

If cases[variable] is not exist then similar logic applied to defaultCase. If defaultCase is function then defaultCase(variable) will be returned and defaultCase otherwise.

More practical examples:

Currying in iterating functions.

import switchCase from 'fp-switch';

const digits = {
    0: 'Zero',
    1: 'One',
    2: 'Two',
    3: 'Three',
    4: 'Four',
    5: 'Five',
    6: 'Six',
    7: 'Seven',
    8: 'Eight',
    9: 'Nine'
};

const getDigitString = switchCase(-1, digits)
const convertDigitsToString = map(getDigitString);

Switches with predefined default behavior

const identitySwitch = switchCase(v => v);
const nullSwitch = switchCase(null);
const undefSwitch = switchCase(undefined);
const strictSwitch = switchCase(() => throw new Error('no case found'));

To know why switch statement sucks and why you need functional switch read my article on medium