Address some of the fusion issues in #202 #241
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
it is marked as `NOINLINE` and has no rules that match on it otherwise, so no fusion can happen.
it would previously replace `takeWhileEnd p` with
S.reverse . S.takeWhile p . S.reverseStream
But `S.reverse` can only fuse with its argument, and `S.reverseStream`
only fuses with its consumer. So all possible fusion is within this
pipeline, and in the best case we obtain a direct implementation.
There might be some value in this if we had a
`S.reverseStream/S.reverse` rule, so that in multiple chained invocations
of `takeWhileEnd` we could eliminate some intermediat steps. But no such
rule exists at the moment.
There is a comment that > length needs to be phased after the `compareN/length` rules otherwise > it may inline before the rules have an opportunity to fire. but these rules are marked `[~1]`, so we can inline `length` in phase 1 to expose the `stream` in its definition and actually allow it to fuse.
This mirrors commits 1e10823, just for strict functions.
as it does a case match.
because `dropWhileEnd` is not.
it was matching on `singleton`, but `singleton` gets rewritten to `s.singleton`. An additional rule makes this robust.
because the rules for `dropWhile` are only enabled before phase 1
nomeata
added a commit
to nomeata/inspection-testing
that referenced
this pull request
Nov 17, 2018
which I have submitted in haskell/text#241
Contributor
Author
|
Is this mergeable? |
Member
|
@nomeata yes, it's mergeable... thanks :-) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
in most cases, just updating the docs. More interesting stuff for
takeWhileEndandlength, see the corresponding commits. See #202.