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0 pointsorblivion8y ago0 comments

Currying

0 comments

I can get the same effect as currying with C syntax by deliberating invoking a special function:

    functools.partial(old_function, my_new_argument)

Is this such a useful thing that you need the functional style syntax to make it even easier to do?

orblivionOP8y ago

You can do it in Python as you have, but it becomes second nature with Haskell (I can't speak to Elm directly). You might not even realize you're doing it.

Add 5 to each num in a list (using a pretend function called `add` in both languages to be fair):

  map(functools.partial(add, 5), nums)

  map (add 5) nums

Add 5 to each in a list of list of numbers:

  map(functools.partial(map, functools.partial(add, 5)), nums)

  map (map (add 5)) nums

winstonewert8y ago

I suppose it would make more sense to write these as lambdas in a c style syntax

   nums.map(|sublist| sublist.map(|num| add(num, 5))

Maybe I haven't done enough functional programming yet, but I still like the explicitness of the C-style over the functional style.

kasbah8y ago

Sorry, but there is nothing more explicit about using lambdas as you have done, it's simply redundant (notice the repetition of sublist and num arguments).

nathancahill8y ago

Yes

j / k navigate · click thread line to collapse

0 comments

winstonewert8y ago

I can get the same effect as currying with C syntax by deliberating invoking a special function:

    functools.partial(old_function, my_new_argument)

Is this such a useful thing that you need the functional style syntax to make it even easier to do?

orblivionOP8y ago

You can do it in Python as you have, but it becomes second nature with Haskell (I can't speak to Elm directly). You might not even realize you're doing it.

Add 5 to each num in a list (using a pretend function called `add` in both languages to be fair):

  map(functools.partial(add, 5), nums)

  map (add 5) nums

Add 5 to each in a list of list of numbers:

  map(functools.partial(map, functools.partial(add, 5)), nums)

  map (map (add 5)) nums

winstonewert8y ago

I suppose it would make more sense to write these as lambdas in a c style syntax

   nums.map(|sublist| sublist.map(|num| add(num, 5))

Maybe I haven't done enough functional programming yet, but I still like the explicitness of the C-style over the functional style.

kasbah8y ago

Sorry, but there is nothing more explicit about using lambdas as you have done, it's simply redundant (notice the repetition of sublist and num arguments).

nathancahill8y ago

Yes

j / k navigate · click thread line to collapse