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| author | Ben Gamari <bgamari.foss@gmail.com> | 2016-01-19 16:30:26 +0100 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2016-01-20 17:08:05 +0100 |
| commit | 5cce09543db827e662539523ffff4513deb92777 (patch) | |
| tree | 56b57340d0853f6a59377119cadb5863f57866bd /compiler | |
| parent | 0373a8458a9d5ed0732d06ffd082b939c11b6adc (diff) | |
| download | haskell-5cce09543db827e662539523ffff4513deb92777.tar.gz | |
Use (&&) instead of `if` in Ix derivation
We were previously using `if` in the derivation of `Ix` instances. This
interacts badly with RebindableSyntax as the typechecker doesn't infer
the type of the argument we give to `tagToEnum#`.
Previously we produced, `if (ch >= ah) then (ch <= bh) else False`.
We now produce `(ch >= ah) && (ch <= bh)`
Fixes #11396.
Test Plan: Validate
Reviewers: austin, simonpj
Reviewed By: simonpj
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D1797
GHC Trac Issues: #11396
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/typecheck/TcGenDeriv.hs | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/compiler/typecheck/TcGenDeriv.hs b/compiler/typecheck/TcGenDeriv.hs index c4279a7698..218c0a4991 100644 --- a/compiler/typecheck/TcGenDeriv.hs +++ b/compiler/typecheck/TcGenDeriv.hs @@ -783,16 +783,19 @@ gen_Ix_binds loc tycon )) ) + -- This produces something like `(ch >= ah) && (ch <= bh)` enum_inRange = mk_easy_FunBind loc inRange_RDR [nlTuplePat [a_Pat, b_Pat] Boxed, c_Pat] $ untag_Expr tycon [(a_RDR, ah_RDR)] ( untag_Expr tycon [(b_RDR, bh_RDR)] ( untag_Expr tycon [(c_RDR, ch_RDR)] ( - nlHsIf (genPrimOpApp (nlHsVar ch_RDR) geInt_RDR (nlHsVar ah_RDR)) ( - (genPrimOpApp (nlHsVar ch_RDR) leInt_RDR (nlHsVar bh_RDR)) - ) {-else-} ( - false_Expr - )))) + -- This used to use `if`, which interacts badly with RebindableSyntax. + -- See #11396. + nlHsApps and_RDR + [ genPrimOpApp (nlHsVar ch_RDR) geInt_RDR (nlHsVar ah_RDR) + , genPrimOpApp (nlHsVar ch_RDR) leInt_RDR (nlHsVar bh_RDR) + ] + ))) -------------------------------------------------------------- single_con_ixes |