maxintfloat() (#55)

* maxintfloat()

* review updates

Author: jmkuhn

src/DecFP.jl

@@ -319,6 +319,10 @@ for T in (Dec32,Dec64,Dec128)
     end
 end
 
+Base.maxintfloat(::Type{Dec32}) = reinterpret(Dec32, 0x36000001) # Dec32("1e7")
+Base.maxintfloat(::Type{Dec64}) = reinterpret(Dec64, 0x33c0000000000001) # Dec64("1e16")
+Base.maxintfloat(::Type{Dec128}) = reinterpret(Dec128, 0x30840000000000000000000000000001) # Dec128("1e34")
+
 Base.convert(T::Type{F}, x::Union{Int8,UInt8,Int16,UInt16}) where {F<:DecimalFloatingPoint} = F(Int32(x))
 Base.convert(T::Type{F}, x::Integer) where {F<:DecimalFloatingPoint} = F(Int64(x))
 Base.convert(T::Type{F}, x::Unsigned) where {F<:DecimalFloatingPoint} = F(UInt64(x))

test/runtests.jl

@@ -102,6 +102,10 @@ for T in (Dec32, Dec64, Dec128)
     @test nextfloat(T(1.5e10)) == 1.5e10 + eps(T(1.5e10))
     @test prevfloat(T(1.5e10)) == 1.5e10 - eps(T(1.5e10))
 
+    @test eps(maxintfloat(T) - 1) == 1
+    @test eps(maxintfloat(T)) == 10
+    @test maxintfloat(T) == maxintfloat(T)+1 > maxintfloat(T)-1 > maxintfloat(T)-2
+
     for f in (isnan,isinf,isfinite,issubnormal,abs)
         @test f(xd) == f(x)
     end