Add parsing for binary and octal fractional literals.

I doubt these are super common but we add them for completeness,
and because with the floats we can print in those bases

src/Cryptol/Parser/AST.hs

@@ -285,7 +285,9 @@ data NumInfo  = BinLit Int                      -- ^ n-digit binary literal
                 deriving (Eq, Show, Generic, NFData)
 
 -- | Information about fractional literals.
-data FracInfo = DecFrac
+data FracInfo = BinFrac
+              | OctFrac
+              | DecFrac
               | HexFrac
                 deriving (Eq,Show,Generic,NFData)
 
@@ -644,13 +646,15 @@ ppFracLit :: Rational -> FracInfo -> Doc
 ppFracLit x i
   | toRational dbl == x =
     case i of
+      BinFrac -> frac
+      OctFrac -> frac
       DecFrac -> text (showFloat dbl "")
       HexFrac -> text (showHFloat dbl "")
-  | otherwise =
-    "fraction`" <.> braces
-                      (commaSep (map integer [ numerator x, denominator x ]))
+  | otherwise = frac
   where
   dbl = fromRational x :: Double
+  frac = "fraction`" <.> braces
+                      (commaSep (map integer [ numerator x, denominator x ]))
 
 
 ppNumLit :: Integer -> NumInfo -> Doc

src/Cryptol/Parser/Lexer.x

@@ -45,11 +45,15 @@ $unitick        = \x7
 @qual_id      = @qual @id
 @qual_op      = @qual @op
 
-@num2         = "0b" (_*[0-1])+
-@num8         = "0o" (_*[0-7])+
-@num10        = [0-9](_*[0-9])*
+@digits2      = (_*[0-1])+
+@digits8      = (_*[0-7])+
 @digits16     = (_*[0-9A-Fa-f])+
+@num2         = "0b" @digits2
+@num8         = "0o" @digits8
+@num10        = [0-9](_*[0-9])*
 @num16        = "0x" @digits16
+@fnum2        = @num2  "." @digits2   ([pP] [\+\-]? @num10)?
+@fnum8        = @num8  "." @digits8   ([pP] [\+\-]? @num10)?
 @fnum10       = @num10 "." @num10     ([eE] [\+\-]? @num10)?
 @fnum16       = @num16 "." @digits16  ([pP] [\+\-]? @num10)?
 
@@ -130,6 +134,8 @@ $white+                   { emit $ White Space }
 @num8                     { emitS (numToken 8  . Text.drop 2) }
 @num10                    { emitS (numToken 10 . Text.drop 0) }
 @num16                    { emitS (numToken 16 . Text.drop 2) }
+@fnum2                    { emitS (fnumToken 2 . Text.drop 2) }
+@fnum8                    { emitS (fnumToken 8 . Text.drop 2) }
 @fnum10                   { emitS (fnumToken 10 . Text.drop 0) }
 @fnum16                   { emitS (fnumToken 16 . Text.drop 2) }
 

src/Cryptol/Parser/ParserUtils.hs

@@ -214,6 +214,8 @@ fracLit :: TokenT -> Expr PName
 fracLit tok =
   case tok of
     Frac x base
+      | base == 2   -> ELit $ ECFrac x BinFrac
+      | base == 8   -> ELit $ ECFrac x OctFrac
       | base == 10  -> ELit $ ECFrac x DecFrac
       | base == 16  -> ELit $ ECFrac x HexFrac
     _ -> panic "[Parser] fracLit" [ "Invalid fraction", show tok ]

src/Cryptol/TypeCheck/Infer.hs

@@ -127,6 +127,8 @@ desugarLiteral lit =
          let arg f = P.PosInst (P.TNum (f fr))
              rnd   = P.PosInst (P.TNum (case info of
                                           P.DecFrac -> 0
+                                          P.BinFrac -> 1
+                                          P.OctFrac -> 1
                                           P.HexFrac -> 1))
          in P.EAppT fracPrim [ arg numerator, arg denominator, rnd ]
 

tests/regression/frac_lit.icry

@@ -0,0 +1,13 @@
+0b1.1     : Rational
+0o1.1     : Rational
+1.1       : Rational
+0x1.1     : Rational
+0b1.1p3   : Rational
+0o1.1p3   : Rational
+1.1e3     : Rational
+0x1.1p3   : Rational
+0b1.1p-3  : Rational
+0o1.1p-3  : Rational
+1.1e-3    : Rational
+0x1.1p-3  : Rational
+

tests/regression/frac_lit.icry.stdout

@@ -0,0 +1,13 @@
+Loading module Cryptol
+(ratio 3 2)
+(ratio 9 8)
+(ratio 11 10)
+(ratio 17 16)
+(ratio 12 1)
+(ratio 9 1)
+(ratio 1100 1)
+(ratio 17 2)
+(ratio 3 16)
+(ratio 9 64)
+(ratio 11 10000)
+(ratio 17 128)