add bitstring (#6)

rfourquet · Aug 26, 2019 · 7578d46 · 7578d46
1 parent dce6fd8
commit 7578d46
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/src/BitIntegers.jl b/src/BitIntegers.jl
@@ -3,8 +3,8 @@
 module BitIntegers
 
 import Base: &, *, +, -, <, <<, <=, ==, >>, >>>, |, ~, AbstractFloat, add_with_overflow,
-             bswap, checked_abs, count_ones, div, flipsign, isodd, leading_zeros, mod,
-             mul_with_overflow, ndigits0zpb, promote_rule, rem, sub_with_overflow,
+             bitstring, bswap, checked_abs, count_ones, div, flipsign, isodd, leading_zeros,
+             mod, mul_with_overflow, ndigits0zpb, promote_rule, rem, sub_with_overflow,
              trailing_zeros, typemax, typemin, unsigned, xor
 
 using Base: add_int, and_int, ashr_int, bswap_int, checked_sadd_int, checked_sdiv_int,
@@ -421,6 +421,7 @@ end
 ndigits0zpb(x::XBS, b::Integer) = ndigits0zpb(unsigned(abs(x)), Int(b))
 ndigits0zpb(x::XBU, b::Integer) = ndigits0zpb(x, Int(b))
 
+bitstring(x::XBI) = string(reinterpret(uinttype(typeof(x)), x), pad = 8*sizeof(x), base = 2)
 
 # * rand
 

diff --git a/test/runtests.jl b/test/runtests.jl
@@ -277,6 +277,16 @@ end
     end
 end
 
+@testset "bitstring" begin
+    @test bitstring(UInt256(3)) == bitstring(Int256(3)) == '0'^254 * "11"
+    @test bitstring(UInt512(3) << 256) == bitstring(Int512(3) << 256) == '0'^254 * "11" * '0'^256
+    let (x, y) = rand(UInt128, 2)
+        u = UInt1024(x) << 512 + UInt1024(y)
+        v = u + UInt1024(1) << 1023
+        @test bitstring(u) == bitstring(Int1024(u)) == '0'^384 * bitstring(x) * '0'^384 * bitstring(y)
+        @test bitstring(v) == bitstring(typemin(Int1024) + Int1024(u)) == '1' * '0'^383 * bitstring(x) * '0'^384 * bitstring(y)
+    end
+end
 
 @testset "floats" begin
     for X in XInts