shithub: MicroHs

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Refactor lexing numbers with base prefix

--- a/src/MicroHs/Lex.hs

+++ b/src/MicroHs/Lex.hs

@@ -82,18 +82,9 @@

     (ds, rs) -> tIdent loc [] (d:ds) (lex (addCol loc $ 1 + length ds) rs)

 lex loc cs@(d:_) | isUpper d = upperIdent loc loc [] cs

 lex loc ('0':x:cs)

-  | toLower x == 'x' =

-    case readIntBase 16 isHexDigit cs of

-      Just (n, len, rs) -> TInt loc n : lex (addCol loc $ len + 2) rs

-      Nothing -> TInt loc 0 : lex (addCol loc 1) (x : cs)

-  | toLower x == 'o' =

-    case readIntBase 8 isOctDigit cs of

-      Just (n, len, rs) -> TInt loc n : lex (addCol loc $ len + 2) rs

-      Nothing -> TInt loc 0 : lex (addCol loc 1) (x : cs)

-  | toLower x == 'b' =

-    case readIntBase 2 isBinDigit cs of

-      Just (n, len, rs) -> TInt loc n : lex (addCol loc $ len + 2) rs

-      Nothing -> TInt loc 0 : lex (addCol loc 1) (x : cs)

+  | toLower x == 'x' = lexNumBasePrefix x 16 isHexDigit loc cs

+  | toLower x == 'o' = lexNumBasePrefix x  8 isOctDigit loc cs

+  | toLower x == 'b' = lexNumBasePrefix x  2 isBinDigit loc cs

   where isBinDigit c = c == '0' || c == '1'

 lex loc cs@(d:_) | isDigit d =

   case readNumDec cs of

@@ -137,6 +128,13 @@

 nested :: SLoc -> [Char] -> [Token]

 nested loc ('#':cs) = pragma loc cs

 nested loc cs = skipNest loc 1 cs

+

+-- lex a number of the form '0':x:cs

+lexNumBasePrefix :: Char -> Integer -> (Char -> Bool) -> SLoc -> String -> [Token]

+lexNumBasePrefix x base isDig loc cs =

+  case readIntBase base isDig cs of

+    Just (n, len, rs) -> TInt loc n : lex (addCol loc $ len + 2) rs

+    Nothing -> TInt loc 0 : lex (addCol loc 1) (x : cs)

 readIntBase :: Integer -> (Char -> Bool) -> String -> Maybe (Integer, Int, String)

 readIntBase base isDig ds =

-- 

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