foldWhile (alternative to deepFind) #58
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The name "foldWhile" might not specify "depth", so perhaps something else? |
deepTransform
Transforms a recursive iterable by a given function. Works like deepMap but
allows you to stop transforming at any point of the tree. The traversing
happens depth first.
deepFind
Goes over every `{ key, value }` of a recursive iterable data structure (for
arrays being numeric key and the value at the key position), and uses a function to extract
elements at any point in the tree onto an array that is returned. If a third
argument, the limit, is provided, it will stop iterating as soon as the number
of found objects reaches that limit.
Why?
Because this will allow me to find the first two nested occurrences of a terms
object with a field property and to modify the first so that it has:
`collect_mode: 'breadth_first'`
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Ramda has: http://ramdajs.com/docs/#reduceWhile but it's not recursive. There was a There are several other things that are deprecated and/or don't stop, like: https://github.com/Carrooi/Node-RecursiveMerge , https://github.com/Raynos/reduce , https://github.com/jonschlinkert/object.reduce 🍭 I'll make the PR to lodash, but this is pretty generic though, Haskell has these kind of functional structures everywhere. It follows the nature of a reduce, but it separates reduce's accumulation from the recursive use of |
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Lodash-contrib has a recursive walk, but it doesn't stop: https://github.com/node4good/lodash-contrib/blob/master/dist/lodash-contrib.js#L348 we can use it to map and reduce, but for efficiency we would need to make a PR. I'm not sure if we need their other functions though: https://github.com/node4good/lodash-contrib/blob/master/docs/index.md |
| let innerFold = o => !isTraversable(o) ? o : _.every(k => fn(r, o[k], k) && innerFold(o[k]), _.keys(o)) | ||
| innerFold(obj) | ||
| return r | ||
| }) |
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@daedalus28 fixed the style though :)
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Fun fact: you can write it without lodash: const foldWhile = (fn, obj, r = []) => {
let innerFold = o => !(typeof o === 'object') ? o
: Object.keys(o).every(k => fn(r, o[k], k) && innerFold(o[k]))
innerFold(obj)
return r
} |
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Other libraries:
(loading) |
More abstract universal [foldWhile](#58), for infinite reducers.
More abstract universal [foldWhile](#58), for infinite reducers.
More abstract universal [foldWhile](#58), for infinite reducers.
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Closing this on favor of the groupid |
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