fix isinteger

fixes JuliaMath#120 : `isinteger(1N0f8)` should be true

src/FixedPointNumbers.jl

@@ -5,8 +5,8 @@ module FixedPointNumbers
 using Base: reducedim_initarray
 
 import Base: ==, <, <=, -, +, *, /, ~, isapprox,
-             convert, promote_rule, show, isinteger, abs, decompose,
-             isnan, isinf, isfinite,
+             convert, promote_rule, show, eger, abs, decompose,
+             isnan, isinf, isfinite, isinteger,
              zero, oneunit, one, typemin, typemax, floatmin, floatmax, eps, sizeof, reinterpret,
              float, trunc, round, floor, ceil, bswap,
              div, fld, rem, mod, mod1, fld1, min, max, minmax,

src/normed.jl

@@ -169,3 +169,6 @@ end
 
 _unsafe_trunc(::Type{T}, x::Integer) where {T} = x % T
 _unsafe_trunc(::Type{T}, x) where {T}          = unsafe_trunc(T, x)
+
+# predicates
+isinteger(x::Normed{T,f}) where {T,f} = (x.i%(1<<f-1)) == 0

test/fixed.jl

@@ -146,6 +146,14 @@ end
     @test floatmin(Q11f4) == Q11f4(0.06)
 end
 
+@testset "isinteger" begin
+    # issue #120
+    for T in (Fixed{Int8,6}, Fixed{Int16,8}, Fixed{Int16,10}, Fixed{Int32,16})
+        a = 1
+        @test all(isinteger.(T.(a)))
+    end
+end
+
 @testset "Disambiguation constructors" begin
     @test_throws ArgumentError Fixed{Int32,16}('a')
     @test_throws InexactError  Fixed{Int32,16}(complex(1.0, 1.0))

test/normed.jl

@@ -345,6 +345,14 @@ end
     @test summary(view(a, 1:2)) == "2-element view(::Array{N0f8,1}, 1:2) with eltype Normed{UInt8,8}"
 end
 
+@testset "isinteger" begin
+    # issue #120
+    for T in (Normed{UInt8,6}, Normed{UInt16,8}, Normed{UInt16,10}, Normed{UInt32,16})
+        a = 1
+        @test all(isinteger.(T.(a)))
+    end
+end
+
 @testset "disambiguation constructors" begin
     @test_throws ArgumentError Normed{UInt32,16}('a')
     @test_throws InexactError  Normed{UInt32,16}(complex(1.0, 1.0))