Allow EXCEPTION effect in updates #58
Merged
Conversation
This file contains 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
jagajaga
pushed a commit
to input-output-hk/rscoin-haskell
that referenced
this pull request
Jul 22, 2016
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
I'm submitting this as a workaround for purescript/purescript#2236.
The problem that's arising is that as long as we disallow duplicate labels in rows, the current setup of the effect rows in pux prevents the
err :: EXCEPTIONeffect from appearing inupdate(maybe that's a good thing though? 馃槈). So in the linked issue, there's no type that can satisfy the requirements of both the implementation ofupdateand its usage within pux.The issue arises due to the signature of
launchAff, but since it is only extending the row withEXCEPTION, theunsafeInterleaveAffcoercion is safe here, since we're not arbitrarily removing some effect that could occur.