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| author | Bartosz Nitka <niteria@gmail.com> | 2016-05-24 02:56:59 -0700 |
|---|---|---|
| committer | Bartosz Nitka <niteria@gmail.com> | 2016-05-24 04:33:21 -0700 |
| commit | 4c6e69d58a300d6ef440d326a3fd29b58b284fa1 (patch) | |
| tree | 6653f56c150c3aa988a96c50359d53f27f2edb01 /compiler/typecheck/TcSimplify.hs | |
| parent | 8f7d01632cd79957fe42ea37103ca9b91a1c54f5 (diff) | |
| download | haskell-4c6e69d58a300d6ef440d326a3fd29b58b284fa1.tar.gz | |
Document some benign nondeterminism
I've changed the functions to their nonDet equivalents and explained
why they're OK there. This allowed me to remove foldNameSet,
foldVarEnv, foldVarEnv_Directly, foldVarSet and foldUFM_Directly.
Test Plan: ./validate, there should be no change in behavior
Reviewers: simonpj, simonmar, austin, goldfire, bgamari
Reviewed By: bgamari
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D2244
GHC Trac Issues: #4012
Diffstat (limited to 'compiler/typecheck/TcSimplify.hs')
| -rw-r--r-- | compiler/typecheck/TcSimplify.hs | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/compiler/typecheck/TcSimplify.hs b/compiler/typecheck/TcSimplify.hs index 07c0a234f4..4c621ddf2f 100644 --- a/compiler/typecheck/TcSimplify.hs +++ b/compiler/typecheck/TcSimplify.hs @@ -42,6 +42,7 @@ import Unify ( tcMatchTy ) import Util import Var import VarSet +import UniqFM import BasicTypes ( IntWithInf, intGtLimit ) import ErrUtils ( emptyMessages ) import qualified GHC.LanguageExtensions as LangExt @@ -1367,7 +1368,9 @@ neededEvVars ev_binds initial_seeds also_needs :: VarSet -> VarSet also_needs needs - = foldVarSet add emptyVarSet needs + = nonDetFoldUFM add emptyVarSet needs + -- It's OK to use nonDetFoldUFM here because we immediately forget + -- about the ordering by creating a set where add v needs | Just ev_bind <- lookupEvBind ev_binds v |