#include "HsVersions.h"
import {-# SOURCE #-} HsExpr( SyntaxExpr, pprExpr )
-import HsTypes (PostTcType)
+import BasicTypes ( FractionalLit(..) )
+import HsTypes ( PostTcType )
import Type ( Type )
import Outputable
import FastString
| HsWordPrim Integer -- Unboxed Word
| HsInteger Integer Type -- Genuinely an integer; arises only from TRANSLATION
-- (overloaded literals are done with HsOverLit)
- | HsRat Rational Type -- Genuinely a rational; arises only from TRANSLATION
+ | HsRat FractionalLit Type -- Genuinely a rational; arises only from TRANSLATION
-- (overloaded literals are done with HsOverLit)
- | HsFloatPrim Rational -- Unboxed Float
- | HsDoublePrim Rational -- Unboxed Double
+ | HsFloatPrim FractionalLit -- Unboxed Float
+ | HsDoublePrim FractionalLit -- Unboxed Double
deriving (Data, Typeable)
instance Eq HsLit where
data HsOverLit id -- An overloaded literal
= OverLit {
ol_val :: OverLitVal,
- ol_rebindable :: Bool, -- True <=> rebindable syntax
- -- False <=> standard syntax
+ ol_rebindable :: Bool, -- Note [ol_rebindable]
ol_witness :: SyntaxExpr id, -- Note [Overloaded literal witnesses]
ol_type :: PostTcType }
deriving (Data, Typeable)
data OverLitVal
= HsIntegral !Integer -- Integer-looking literals;
- | HsFractional !Rational -- Frac-looking literals
+ | HsFractional !FractionalLit -- Frac-looking literals
| HsIsString !FastString -- String-looking literals
deriving (Data, Typeable)
overLitType = ol_type
\end{code}
+Note [ol_rebindable]
+~~~~~~~~~~~~~~~~~~~~
+The ol_rebindable field is True if this literal is actually
+using rebindable syntax. Specifically:
+
+ False iff ol_witness is the standard one
+ True iff ol_witness is non-standard
+
+Equivalently it's True if
+ a) RebindableSyntax is on
+ b) the witness for fromInteger/fromRational/fromString
+ that happens to be in scope isn't the standard one
+
Note [Overloaded literal witnesses]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*Before* type checking, the SyntaxExpr in an HsOverLit is the
This dual role is unusual, because we're replacing 'fromInteger' with
a call to fromInteger. Reason: it allows commoning up of the fromInteger
-calls, which wouldn't be possible if the desguarar made the application
+calls, which wouldn't be possible if the desguarar made the application.
The PostTcType in each branch records the type the overload literal is
found to have.
ppr (HsStringPrim s) = pprHsString s <> char '#'
ppr (HsInt i) = integer i
ppr (HsInteger i _) = integer i
- ppr (HsRat f _) = rational f
- ppr (HsFloatPrim f) = rational f <> char '#'
- ppr (HsDoublePrim d) = rational d <> text "##"
+ ppr (HsRat f _) = ppr f
+ ppr (HsFloatPrim f) = ppr f <> char '#'
+ ppr (HsDoublePrim d) = ppr d <> text "##"
ppr (HsIntPrim i) = integer i <> char '#'
ppr (HsWordPrim w) = integer w <> text "##"
instance Outputable OverLitVal where
ppr (HsIntegral i) = integer i
- ppr (HsFractional f) = rational f
+ ppr (HsFractional f) = ppr f
ppr (HsIsString s) = pprHsString s
\end{code}