Re: [elm-discuss] Order of arguments in mapping function in foldl/foldp

[Evan Czaplicki]

Yep! http://package.elm-lang.org/help/design-guidelines#the-data-structure-is-always-the-last-argument

From working with SML, OCaml, and Haskell, I always found the SML way the best. Changing the order of traversal does not change anything else about your code. Furthermore, you don't have to go look at the docs every single time to remember which is which (a thing I still do sometimes in Haskell: "which way does foldM go?")

On Sat, Jun 27, 2015 at 8:09 AM, Robert Looby <robert...@gmail.com> wrote:

The function passed to List.foldl/List.foldp has the current value first and the accumulated value second. Ex)

List.foldl (\element memo -> memo ++ element) "a" ["b", "c", "d"] -- "abcd"

This is backwards from similar functions in most other languages:

Ruby

Haskell

Clojure

Underscore.js

Java

C++

PHP

Python

C#

Is there a reason it was done this way?

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