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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2020-01-08 16:28:26 +0000 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-01-12 21:32:44 -0500 |
| commit | 61916c5d038c3b0e87148d3b46149a32f7379ea9 (patch) | |
| tree | a4a6652213ca542dfce9a65cdc9dd1401a7c9c9e | |
| parent | 077a88de5c0981badbb61b06f32073d7f3a49b08 (diff) | |
| download | haskell-61916c5d038c3b0e87148d3b46149a32f7379ea9.tar.gz | |
Add comments about TH levels
| -rw-r--r-- | compiler/typecheck/TcExpr.hs | 4 | ||||
| -rw-r--r-- | compiler/typecheck/TcRnTypes.hs | 12 | ||||
| -rw-r--r-- | compiler/typecheck/TcSplice.hs | 2 |
3 files changed, 12 insertions, 6 deletions
diff --git a/compiler/typecheck/TcExpr.hs b/compiler/typecheck/TcExpr.hs index 6fb3af4839..fd986cb2d1 100644 --- a/compiler/typecheck/TcExpr.hs +++ b/compiler/typecheck/TcExpr.hs @@ -1957,6 +1957,9 @@ too_many_args fun args -} checkThLocalId :: Id -> TcM () +-- The renamer has already done checkWellStaged, +-- in RnSplice.checkThLocalName, so don't repeat that here. +-- Here we just just add constraints fro cross-stage lifting checkThLocalId id = do { mb_local_use <- getStageAndBindLevel (idName id) ; case mb_local_use of @@ -1973,7 +1976,6 @@ checkCrossStageLifting :: TopLevelFlag -> Id -> ThStage -> TcM () -- we must check whether there's a cross-stage lift to do -- Examples \x -> [|| x ||] -- [|| map ||] --- There is no error-checking to do, because the renamer did that -- -- This is similar to checkCrossStageLifting in GHC.Rename.Splice, but -- this code is applied to *typed* brackets. diff --git a/compiler/typecheck/TcRnTypes.hs b/compiler/typecheck/TcRnTypes.hs index 49df7a909a..8a299d3d50 100644 --- a/compiler/typecheck/TcRnTypes.hs +++ b/compiler/typecheck/TcRnTypes.hs @@ -911,7 +911,12 @@ removeBindingShadowing bindings = reverse $ fst $ foldl data SpliceType = Typed | Untyped -data ThStage -- See Note [Template Haskell state diagram] in TcSplice +data ThStage -- See Note [Template Haskell state diagram] + -- and Note [Template Haskell levels] in TcSplice + -- Start at: Comp + -- At bracket: wrap current stage in Brack + -- At splice: currently Brack: return to previous stage + -- currently Comp/Splice: compile and run = Splice SpliceType -- Inside a top-level splice -- This code will be run *at compile time*; -- the result replaces the splice @@ -980,11 +985,10 @@ outerLevel = 1 -- Things defined outside brackets thLevel :: ThStage -> ThLevel thLevel (Splice _) = 0 -thLevel (RunSplice _) = - -- See Note [RunSplice ThLevel]. - panic "thLevel: called when running a splice" thLevel Comp = 1 thLevel (Brack s _) = thLevel s + 1 +thLevel (RunSplice _) = panic "thLevel: called when running a splice" + -- See Note [RunSplice ThLevel]. {- Node [RunSplice ThLevel] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/compiler/typecheck/TcSplice.hs b/compiler/typecheck/TcSplice.hs index b23314adb0..5ff4c314b3 100644 --- a/compiler/typecheck/TcSplice.hs +++ b/compiler/typecheck/TcSplice.hs @@ -466,7 +466,7 @@ Note [Template Haskell levels] incremented by brackets [| |] incremented by name-quoting 'f -When a variable is used, we compare +* When a variable is used, checkWellStaged compares bind: binding level, and use: current level at usage site |