A simple implementation of pipe operator for Node.js
npm install weldy
A sort of pipe operator (|>) implementation for Node.js based on co.
weldy takes a value and an array with the following structure [ [fn_1, ...args], [fn_2, ...args], ... ,[fn_n, ...args] ], processes each element invoking fn, using as first argument the output of the previous one (if it returns any value) and the ...args. It returns a promise.
The first argument of the first function can be passed as the first weldy param.
Simple arithmetical operations:
``javascript`
weldy(5, [ // first argument for sqrt function
[ square ],
[ sum, 3, 4, 5 ],
[ sub, 4 ],
[ console.log ] // 33
])
CRUD operations on mongodb:
`javascript
function insert () {
return db.collection('document').insertMany([
{ value: 'object1' },
{ value: 'object2' },
{ value: 'object3' }
])
}
function retrieve (value) {
return db.collection('document').find({ value }).limit(1).next().then(object => object.value)
}
function update (value, newValue) {
console.log(Update collection: ${value} -> ${newValue})
return db.collection('document').updateOne({ value }, { $set: { value: newValue } })
}
function isOk (object) {
console.log(Update ok: ${object.result.ok})
}
insert()
weldy('object1', [
[ retrieve ],
[ update, 'object0' ],
[ isOk ]
])
`
Usage with node-fetch:
`javascript`
weldy('http://github.com', [
[ fetch ],
[ res => res.text() ],
[ console.log ]
])