cond-flow
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Elixir style cond for easy javascript control flow
cond-flow
Inspired by Elixir's cond
this is a simpler alternative to lodash's _.cond
Install
Install with npm or yarn via
yarn add cond-flow
or
npm i cond-flow
API
type Cond = (
pairs: Array<[boolean, unknown | (() => unknown)]>,
options: { strict: boolean }
) => unknown
Usage
import cond from 'cond-flow'
const value = cond([
[false, 'false'],
[true, 'true'],
[true, 'true but too late'],
])
// value === 'true'
You can disable strict checking by passing options as the second argument:
import cond from 'cond-flow'
const value = cond(
[
[false, 'false'],
[1, 'truthy'],
[true, 'true but also too late'],
],
{ strict: false }
)
// value === 'truthy'
Also works nicely with React components as you can have the values lazily evaluated by wrapping it in a function:
import cond from 'cond-flow'
const Component = ({ isDisabled, isNew, isLoading }) => (
<>
{cond([
[isLoading, () => <Loading />],
[isNew, () => <Create />],
[isDisabled, null],
])}
</>
)
Note
As all predicates have to be evaluated before the right branch can be chosen, it can have a negative performance impact if you rely on heavy computations. It's best to have simple booleans and resort to Ramda's cond
for complex use cases.
Development
If you find this useful or would like to add features, feel free to clone the repository and open a PR.