m
Point free style,
functional library for Javascript with focus on object arrays.
Install
npm install @asd14/m
Use
import { pipe, trim, split, dropLast, push, join } from "@asd14/m"
const removeTrailingSlash = source =>
source[source.length - 1] === sep ? source.slice(0, -1) : source
const renameFile = newName =>
pipe(
removeTrailingSlash,
split(sep),
dropLast,
push(trim(sep, newName)),
join(sep)
)
"With" pattern
Some functions have a *With variant. find has findWith, filter has
filterWith etc. They allow for less boilerplate and more intuitive way of
handling object arrays.
import { find, findWith, filterWith, not, is } from "@asd14/m"
const todos = [
{ id: 1, name: "lorem", tagId: 2 },
{ id: 2, name: "ipsum", tagId: null },
{ id: 3, name: "dolor", tagId: null },
]
/* Predicate fn */
find(item => item.id === 1, todos)
// => {id: 1, name: "lorem", tagId: 2}
/* Matching object */
findWith(
{
id: 1,
},
todos
)
// => {id: 1, name: "lorem", tagId: 2}
/* Matching object & predicate fn */
filterWith(
{
tagId: is, // same as `tagId: source => is(source)`
},
todos
)
// => [{id: 1, name: "lorem", tagId: 2}]
/* Syntactic sugar */
filterWith(
{
"!tagId": is, // same as `tagId: not(is)`
},
todos
)
// => [
// {id: 2, name: "ipsum", tagId: null},
// {id: 3, name: "dolor", tagId: null}
// ]
|> pipe
There is no structure difference between pipe and compose, both will use
the same building blocks to get from A to B.
A series of transformations over an initial input can be written as
x -> f -> g -> result, piping, or as result = g(f(x)), composing. The
difference is only syntactic. Input is the same, transformations and order
of application are the same, the result will be the same.
Given that:
it makes sense to choose the syntax more aligned with our intuition and
context. The transformations are applied in a certain order with time as a
medium - input -> t0 -> t1 -> tn -> output.
const { sep } = require("path")
const { pipe, compose, join, push, dropLast, split } = require("@asd14/m")
// Compose: g(f(x))
const renameFile = newName => filePath =>
compose(join(sep), push(newName), dropLast, split(sep))(filePath)
// Pipe: x -> f -> g
const renameFile = newName => filePath =>
pipe(split(sep), dropLast, push(newName), join(sep))(filePath)
// More expressive with pipeline operator
const renameFile = newName => filePath =>
filePath |> split(sep) |> dropLast |> push(newName) |> join(sep)
Develop
git clone git@github.com:asd14-xyz/m.git && \
cd m && \
npm run setup
# run tests (any `*.test.js`) once
npm test
# watch `src` folder for changes and run test automatically
npm run tdd
Contributors
Thank you for contributing your time and knowledge:
Changelog
See the releases section for details.
