From 3c2d70ea29a09536a4721271d928a12ec7d2af84 Mon Sep 17 00:00:00 2001
From: Nick Bowler <nbowler@draconx.ca>
Date: Fri, 19 Feb 2010 00:05:58 -0500
Subject: [PATCH] floating: Add another characteristic function and generalize
 types.

---
 Data/Floating/Classes.hs      | 8 ++++++--
 Data/Floating/Types/Double.hs | 1 +
 Data/Floating/Types/Float.hs  | 1 +
 configure.ac                  | 5 +++++
 4 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/Data/Floating/Classes.hs b/Data/Floating/Classes.hs
index f67f234..4c67026 100644
--- a/Data/Floating/Classes.hs
+++ b/Data/Floating/Classes.hs
@@ -130,7 +130,11 @@ class Floating a => RealFloat a where
 -- | Class for the basic floating point types.
 class (Roundable a, RealFloat a) => PrimFloat a where
     -- | Radix of significand digits.
-    floatRadix     :: a -> Int
+    floatRadix     :: Num b => a -> b
     -- | Number of digits in the significand.
-    floatPrecision :: a -> Int
+    floatPrecision :: Num b => a -> b
+    -- | Minimum and maximum integers, respectively, such that the radix raised
+    -- to one less than that power is representable as a normalized, finite
+    -- floating point number.
+    floatRange     :: Num b => a -> (b, b)
     classify       :: a -> FPClassification
diff --git a/Data/Floating/Types/Double.hs b/Data/Floating/Types/Double.hs
index 6327372..cc6e3b1 100644
--- a/Data/Floating/Types/Double.hs
+++ b/Data/Floating/Types/Double.hs
@@ -163,4 +163,5 @@ instance RealFloat Double where
 instance PrimFloat Double where
     floatRadix     = const FLT_RADIX_VAL
     floatPrecision = const DBL_MANT_DIG_VAL
+    floatRange     = const (DBL_MIN_EXP_VAL, DBL_MAX_EXP_VAL)
     classify       = toEnum . fromIntegral . double_classify . toFloating
diff --git a/Data/Floating/Types/Float.hs b/Data/Floating/Types/Float.hs
index 51f95f6..b8c1f66 100644
--- a/Data/Floating/Types/Float.hs
+++ b/Data/Floating/Types/Float.hs
@@ -159,4 +159,5 @@ instance RealFloat Float where
 instance PrimFloat Float where
     floatRadix     = const FLT_RADIX_VAL
     floatPrecision = const FLT_MANT_DIG_VAL
+    floatRange     = const (FLT_MIN_EXP_VAL, FLT_MAX_EXP_VAL)
     classify       = toEnum . fromIntegral . float_classify . toFloating
diff --git a/configure.ac b/configure.ac
index af5d8a4..7230a97 100644
--- a/configure.ac
+++ b/configure.ac
@@ -42,6 +42,11 @@ CHECK_FLOAT([floating point radix], [FLT_RADIX])
 CHECK_FLOAT([precision of double], [DBL_MANT_DIG], [digits])
 CHECK_FLOAT([precision of float],  [FLT_MANT_DIG], [digits])
 
+CHECK_FLOAT([minimum normal exponent for double], [DBL_MIN_EXP])
+CHECK_FLOAT([maximum finite exponent for double], [DBL_MAX_EXP])
+CHECK_FLOAT([minimum normal exponent for float],  [FLT_MIN_EXP])
+CHECK_FLOAT([maximum finite exponent for float],  [FLT_MAX_EXP])
+
 dnl Check for some C library functions.
 m4_define([C99_FLOAT_FUNCS], [dnl
 	[acosf], [asinf], [atanf], [atan2f], [cosf], [sinf], [tanf], [acoshf],
-- 
2.11.4.GIT