Changeset 8054 for src/Pugs/Prim/Numeric.hs

Timestamp:

12/03/05 07:06:08 (3 years ago)

Author:

luqui

svk:copy_cache_prev:

10519

Message:

Added tests about infinity, and "fixed" op2Exp to make them pass. They should
be checked for correctness.

Files:

• src/Pugs/Prim/Numeric.hs (modified) (2 diffs)

src/Pugs/Prim/Numeric.hs

@@ -61 +61 @@
             if isDigit . head $ show (num1 :: VNum)
                 then op2Rat ((^^) :: VRat -> VInt -> VRat) x y
-                else op2Num ((**) :: VNum -> VNum -> VNum) x y
-        _ -> op2Num ((**) :: VNum -> VNum -> VNum) x y
+                else op2Num numExp x y
+        _ -> op2Num numExp x y
+    where
+    numExp :: VNum -> VNum -> VNum
+    -- Perl 6 differs from Haskell in the floating point spec wrt Infinity and NaN
+    numExp x y 
+        | x == 1/0 && y == 0                           = 0/0
+        | x == 0  && y < 0                             = 0/0
+        | y == 1/0 && (x == 1 || x <= -1)              = 0/0 
+        | y == -1/0 && (x == 1 || (x >= -1 && x <= 0)) = 0/0 
+        | otherwise                                    = x ** y
 
 op2Divide :: Val -> Val -> Eval Val
@@ -77 +86 @@
     = op2Num (/) x y
     where
-    err = fail "Illegal division by zero"
+    err = fail "Illegal division by zero"  -- XXX why not NaN?
 
 op2Modulus :: Val -> Val -> Eval Val