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| author | Simon Peyton Jones <simonpj@microsoft.com> | 2020-04-08 23:08:12 +0100 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2020-04-22 23:13:06 -0400 |
| commit | ffde234854f49dba9ec4735aad74b30fd2deee29 (patch) | |
| tree | 80409f70e0de9164441d1cf860b386df4318e5c3 /compiler/GHC/Rename/Splice.hs | |
| parent | 34a45ee600d5346f5d1728047fa185698ed7ee84 (diff) | |
| download | haskell-ffde234854f49dba9ec4735aad74b30fd2deee29.tar.gz | |
Do eager instantation in terms
This patch implements eager instantiation, a small but critical change
to the type inference engine, #17173. The main change is this:
When inferring types, always return an instantiated type
(for now, deeply instantiated; in future shallowly instantiated)
There is more discussion in
https://www.tweag.io/posts/2020-04-02-lazy-eager-instantiation.html
There is quite a bit of refactoring in this patch:
* The ir_inst field of GHC.Tc.Utils.TcType.InferResultk
has entirely gone. So tcInferInst and tcInferNoInst have collapsed
into tcInfer.
* Type inference of applications, via tcInferApp and
tcInferAppHead, are substantially refactored, preparing
the way for Quick Look impredicativity.
* New pure function GHC.Tc.Gen.Expr.collectHsArgs and applyHsArgs
are beatifully dual. We can see the zipper!
* GHC.Tc.Gen.Expr.tcArgs is now much nicer; no longer needs to return
a wrapper
* In HsExpr, HsTypeApp now contains the the actual type argument,
and is used in desugaring, rather than putting it in a mysterious
wrapper.
* I struggled a bit with good error reporting in
Unify.matchActualFunTysPart. It's a little bit simpler than before,
but still not great.
Some smaller things
* Rename tcPolyExpr --> tcCheckExpr
tcMonoExpr --> tcLExpr
* tcPatSig moves from GHC.Tc.Gen.HsType to GHC.Tc.Gen.Pat
Metric Decrease:
T9961
Reduction of 1.6% in comiler allocation on T9961, I think.
Diffstat (limited to 'compiler/GHC/Rename/Splice.hs')
| -rw-r--r-- | compiler/GHC/Rename/Splice.hs | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/compiler/GHC/Rename/Splice.hs b/compiler/GHC/Rename/Splice.hs index a0f0bb2419..c8aa73554f 100644 --- a/compiler/GHC/Rename/Splice.hs +++ b/compiler/GHC/Rename/Splice.hs @@ -48,7 +48,7 @@ import GHC.Driver.Hooks import GHC.Builtin.Names.TH ( quoteExpName, quotePatName, quoteDecName, quoteTypeName , decsQTyConName, expQTyConName, patQTyConName, typeQTyConName, ) -import {-# SOURCE #-} GHC.Tc.Gen.Expr ( tcPolyExpr ) +import {-# SOURCE #-} GHC.Tc.Gen.Expr ( tcCheckExpr ) import {-# SOURCE #-} GHC.Tc.Gen.Splice ( runMetaD , runMetaE @@ -324,7 +324,7 @@ runRnSplice flavour run_meta ppr_res splice ; meta_exp_ty <- tcMetaTy meta_ty_name ; zonked_q_expr <- zonkTopLExpr =<< tcTopSpliceExpr Untyped - (tcPolyExpr the_expr meta_exp_ty) + (tcCheckExpr the_expr meta_exp_ty) -- Run the expression ; mod_finalizers_ref <- newTcRef [] @@ -760,7 +760,7 @@ traceSplice (SpliceInfo { spliceDescription = sd, spliceSource = mb_src spliceDebugDoc loc = let code = case mb_src of Nothing -> ending - Just e -> nest 2 (ppr (stripParensHsExpr e)) : ending + Just e -> nest 2 (ppr (stripParensLHsExpr e)) : ending ending = [ text "======>", nest 2 gen ] in hang (ppr loc <> colon <+> text "Splicing" <+> text sd) 2 (sep code) |