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| author | Richard Eisenberg <eir@cis.upenn.edu> | 2015-12-11 18:19:53 -0500 |
|---|---|---|
| committer | Richard Eisenberg <eir@cis.upenn.edu> | 2015-12-11 18:23:12 -0500 |
| commit | 6746549772c5cc0ac66c0fce562f297f4d4b80a2 (patch) | |
| tree | 96869fcfb5757651462511d64d99a3712f09e7fb /compiler/parser/Lexer.x | |
| parent | 6e56ac58a6905197412d58e32792a04a63b94d7e (diff) | |
| download | haskell-6746549772c5cc0ac66c0fce562f297f4d4b80a2.tar.gz | |
Add kind equalities to GHC.
This implements the ideas originally put forward in
"System FC with Explicit Kind Equality" (ICFP'13).
There are several noteworthy changes with this patch:
* We now have casts in types. These change the kind
of a type. See new constructor `CastTy`.
* All types and all constructors can be promoted.
This includes GADT constructors. GADT pattern matches
take place in type family equations. In Core,
types can now be applied to coercions via the
`CoercionTy` constructor.
* Coercions can now be heterogeneous, relating types
of different kinds. A coercion proving `t1 :: k1 ~ t2 :: k2`
proves both that `t1` and `t2` are the same and also that
`k1` and `k2` are the same.
* The `Coercion` type has been significantly enhanced.
The documentation in `docs/core-spec/core-spec.pdf` reflects
the new reality.
* The type of `*` is now `*`. No more `BOX`.
* Users can write explicit kind variables in their code,
anywhere they can write type variables. For backward compatibility,
automatic inference of kind-variable binding is still permitted.
* The new extension `TypeInType` turns on the new user-facing
features.
* Type families and synonyms are now promoted to kinds. This causes
trouble with parsing `*`, leading to the somewhat awkward new
`HsAppsTy` constructor for `HsType`. This is dispatched with in
the renamer, where the kind `*` can be told apart from a
type-level multiplication operator. Without `-XTypeInType` the
old behavior persists. With `-XTypeInType`, you need to import
`Data.Kind` to get `*`, also known as `Type`.
* The kind-checking algorithms in TcHsType have been significantly
rewritten to allow for enhanced kinds.
* The new features are still quite experimental and may be in flux.
* TODO: Several open tickets: #11195, #11196, #11197, #11198, #11203.
* TODO: Update user manual.
Tickets addressed: #9017, #9173, #7961, #10524, #8566, #11142.
Updates Haddock submodule.
Diffstat (limited to 'compiler/parser/Lexer.x')
| -rw-r--r-- | compiler/parser/Lexer.x | 10 |
1 files changed, 0 insertions, 10 deletions
diff --git a/compiler/parser/Lexer.x b/compiler/parser/Lexer.x index db96acbcbc..3f6fa8c6e0 100644 --- a/compiler/parser/Lexer.x +++ b/compiler/parser/Lexer.x @@ -605,7 +605,6 @@ data Token | ITdarrow IsUnicodeSyntax | ITminus | ITbang - | ITstar IsUnicodeSyntax | ITdot | ITbiglam -- GHC-extension symbols @@ -807,9 +806,6 @@ reservedSymsFM = listToUFM $ ,("-", ITminus, always) ,("!", ITbang, always) - -- For data T (a::*) = MkT - ,("*", ITstar NormalSyntax, always) - -- \i -> kindSigsEnabled i || tyFamEnabled i) -- For 'forall a . t' ,(".", ITdot, always) -- \i -> explicitForallEnabled i || inRulePrag i) @@ -833,8 +829,6 @@ reservedSymsFM = listToUFM $ ,("⤜", ITRarrowtail UnicodeSyntax, \i -> unicodeSyntaxEnabled i && arrowsEnabled i) - ,("★", ITstar UnicodeSyntax, unicodeSyntaxEnabled) - -- ToDo: ideally, → and ∷ should be "specials", so that they cannot -- form part of a large operator. This would let us have a better -- syntax for kinds: ɑ∷*→* would be a legal kind signature. (maybe). @@ -2007,7 +2001,6 @@ data ExtBits | PatternSynonymsBit -- pattern synonyms | HaddockBit-- Lex and parse Haddock comments | MagicHashBit -- "#" in both functions and operators - | KindSigsBit -- Kind signatures on type variables | RecursiveDoBit -- mdo | UnicodeSyntaxBit -- the forall symbol, arrow symbols, etc | UnboxedTuplesBit -- (# and #) @@ -2052,8 +2045,6 @@ haddockEnabled :: ExtsBitmap -> Bool haddockEnabled = xtest HaddockBit magicHashEnabled :: ExtsBitmap -> Bool magicHashEnabled = xtest MagicHashBit --- kindSigsEnabled :: ExtsBitmap -> Bool --- kindSigsEnabled = xtest KindSigsBit unicodeSyntaxEnabled :: ExtsBitmap -> Bool unicodeSyntaxEnabled = xtest UnicodeSyntaxBit unboxedTuplesEnabled :: ExtsBitmap -> Bool @@ -2140,7 +2131,6 @@ mkPState flags buf loc = .|. BangPatBit `setBitIf` xopt Opt_BangPatterns flags .|. HaddockBit `setBitIf` gopt Opt_Haddock flags .|. MagicHashBit `setBitIf` xopt Opt_MagicHash flags - .|. KindSigsBit `setBitIf` xopt Opt_KindSignatures flags .|. RecursiveDoBit `setBitIf` xopt Opt_RecursiveDo flags .|. UnicodeSyntaxBit `setBitIf` xopt Opt_UnicodeSyntax flags .|. UnboxedTuplesBit `setBitIf` xopt Opt_UnboxedTuples flags |