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| author | Gergo ERDI <gergo@erdi.hu> | 2022-05-16 14:02:20 +0200 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2022-10-17 19:20:04 -0400 |
| commit | 8c72411d9504963069fb1ae736a2470cb9ae1250 (patch) | |
| tree | 7b3232544dcda6a7c94c423581fd44529768b258 /testsuite/tests | |
| parent | c1e5719aa500cb9e0f2549eb9b9e2255038ac35d (diff) | |
| download | haskell-8c72411d9504963069fb1ae736a2470cb9ae1250.tar.gz | |
Add `Enum (Down a)` instance that swaps `succ` and `pred`
See https://github.com/haskell/core-libraries-committee/issues/51 for
discussion. The key points driving the implementation are the following
two ideas:
* For the `Int` type, `comparing (complement @Int)` behaves exactly as
an order-swapping `compare @Int`.
* `enumFrom @(Down a)` can be implemented in terms of `enumFromThen @a`,
if only the corner case of starting at the very end is handled specially
Diffstat (limited to 'testsuite/tests')
0 files changed, 0 insertions, 0 deletions