Utility library implementing tooling to make stoppable functions...
npm install ig-stoppableUtility library implementing tooling to make stoppable functions...
This library enables the user to drop out of a function/generator without the
need to thread the result through the call stack. This is in concept similar to
executing return .. from a nested loop to terminate and return from a function
but stoppable.js allows us to do the same from a nested set of function calls.
This is also similar to _Python_'s raise StopIteration approach to stopping
iteration.
- stoppable.js
- Install / import
- Components
- stoppable(..)
- stoppable.STOP / stoppable.STOP(..)
- Examples
- Function
- Async function
- Generator
- Async generator
- License
``shell`
$ npm install --save ig-stoppable
`javascript`
var stoppable = require('ig-stoppable')
Create a wrapper for the input function/generator.
`bnf
stoppable(
->
stoppable(
->
stoppable(
->
stoppable(
->
`
A special object/constructor that can either be returned/thrown _as-is_ or
used to create an _instance_ to be returned thrown.
`bnf
stoppable.STOP
stoppable.STOP()
stoppable.STOP(
->
`
This will get intercepted by stoppable(..) and appropriately handled, stopping
the function iterator and merging the value into the yields of a generator or
returning it from a function depending on the wrapper type.
can contain a value that will get handled by stoppable(..) (default: undefined).
`javascript
var func = stoppable(function(){
// ...
throw stoppable.STOP('something')
// ...
})
var value = func() // -> 'something'
`
Dropping out of recursion avoiding threading the result up the chain:
`javascript
// Note that we split the recursive part and the interface part, this is done
// to keep the STOP catching only to the top level and thus avoid threading
// the result back up the recursion...
var _find = function(L, e){
if(L.length == 0){
throw stoppable.STOP(false) }
if(L[0] == e){
throw stoppable.STOP(true) }
// look further down...
_find(L.slice(1), e) }
var find = stoppable(_find)
find([1,2,3,4,5,6,7], 6) // -> true
`
For more examples see type.js' Array.prototype.smap(..) and friends.
javascript
var func = stoppable(async function(){
// ... throw stoppable.STOP('something')
// ...
})
var value = await func() // -> 'something'
`
$3
javascript
var gen = stoppable(function*(){
// ... throw stoppable.STOP('something')
// ...
})
var value = [...gen()] // -> ['somthing']
`
$3
javascript
var agen = stoppable(async function*(){
// ... throw stoppable.STOP('something')
// ...
})
var value = awat agen() // -> ['something']
``Copyright (c) 2022-, Alex A. Naanou,
All rights reserved.