Is a good idea to use lodash sub-packages ? about hm-def HOT 5 CLOSED

Why did Lodash ever appeared among the dependencies? cond and fromPairs were initially provided by Ramda.

— Ramda is not safe, Sanctuary is better, let’s get rid of Ramda in favor of Sanctuary. That was a good idea for #8

But Sanctuary misses a few functions from Ramda. They are quite trivial and are re-implemented on the top of signature.js:

//    isEmpty :: Foldable f => f a -> Boolean
const isEmpty = xs => xs.length === 0;
//    propEq :: String -> a -> StrMap a -> Boolean
const propEq = prop => val => obj => obj[prop] === val;
//    indexBy :: (StrMap a -> String) -> Array (StrMap a) -> StrMap (StrMap a)
const indexBy = memoize
  (f => S.reduce
    (xs => x => S.insert (f (x)) (x) (xs))
    ({}));

The missing cond and fromPairs look trivial too and IMO it is better to just re-implement them the same way and drop the lodash.* dependencies altogether.

PRs are welcome.

from hm-def.

I originally replaced them in a (somewhat misguided) effort to get rid of Ramda. At the time, I didn't bother to just write them myself, but, looking at them now, I see they aren't complicated at all. So I wrote them just now.

//    fromPairs :: Array (Array2 String a) -> StrMap a
const fromPairs = S.reduce
  (acc => curr => S.insert (curr[0]) (curr[1]) (acc))
  ({});
//    cond :: Array (Array2 (a -> Boolean) (a -> b)) -> a -> b
const cond = conds => x => {
  const c = conds.find (y => y[0] (x));
  if (c !== undefined) {
    return c[1] (x);
  }
  throw new Error (`No predicate was satisfied for ${x}`);
};

Unsure whether cond should return undefined or throw if none of the cases match though. Thoughts?

from hm-def.

Oh, thanks. For the strictness and definite return value type exception is fine I think.

from hm-def.

My thoughts exactly.

from hm-def.

This signature is misleading:

//    isEmpty :: Foldable f => f a -> Boolean
const isEmpty = xs => xs.length === 0;

One of the following would be accurate:

//    isEmpty :: { length :: Number } -> Boolean
const isEmpty = xs => xs.length === 0;

//    isEmpty :: Foldable f => f a -> Boolean
const isEmpty = xs => S.size (xs) === 0;

//    isEmpty :: Monoid a => a -> Boolean
const isEmpty = xs => S.equals (xs) (S.empty (xs.constructor));

from hm-def.