Fixed bug in Array.map and Array.indexedMap

[brown-dragon]

Array.map and Array.indexedMap have a bug that can most easily be seen
with the following use case:

EXPECTED: Array.empty == Array.map (\e -> e) Array.empty
ACTUAL: Array.empty != Array.map (\e -> e) Array.empty

(the same for Array.indexedMap)

This is because Array.map/Array.indexedMap initializes itself
incorrectly using:

    table: new Array(a.table)  // creates a new array with an array element

instead of

    table: new Array(a.table.length) // a correctly-sized array

This bug has been fixed in this commit

[brown-dragon]

I just realized this bug has been reported in https://github.com/elm-lang/core/pull/169

However this is a better fix, especially because the bug exists in all Array.map calls
(not just the empty case). It is most visible in the empty case but the initialization is
incorrect in all cases.

[brown-dragon]

I just realized this bug has been reported in https://github.com/elm-lang/core/pull/169

However this is a better fix, especially because the bug exists in all Array.map calls
(not just the empty case). It is most visible in the empty case but the initialization is
incorrect in all cases.

[evancz]

Awesome, thanks for the fix!

[evancz]

Awesome, thanks for the fix!

[TheSeamau5]

Yay! Awesome!

By the way, I just ran elm-check on the old code and it has found the bug.

Map transforms lists and arrays equally has failed with the following input: (<function>,Array.fromList [])

I know it's a bit of a shameless plug, but I think we could look into elm-check integration with the current testing of the standard library. I'm pretty surprised by how well elm-check is currently doing.

[TheSeamau5]

Yay! Awesome!

By the way, I just ran elm-check on the old code and it has found the bug.

Map transforms lists and arrays equally has failed with the following input: (<function>,Array.fromList [])

I know it's a bit of a shameless plug, but I think we could look into elm-check integration with the current testing of the standard library. I'm pretty surprised by how well elm-check is currently doing.

[pchiusano]

Any chance of a 0.14.x patch release for this?

[pchiusano]

Any chance of a 0.14.x patch release for this?

[kasbah]

Prompted by you @pchiusano, I proposed it for next stable with #192.

[kasbah]

Prompted by you @pchiusano, I proposed it for next stable with #192.