add range getindex for Buffer

Author: bicycle1885

src/buffer.jl

@@ -47,6 +47,17 @@ function Base.checkbounds(buf::Buffer, i::Integer)
     end
 end
 
+function Base.getindex(buf::Buffer, r::UnitRange{<:Integer})
+    @boundscheck checkbounds(buf, r)
+    @inbounds return buf.data[r+buf.bufferpos-1]
+end
+
+function Base.checkbounds(buf::Buffer, r::UnitRange{<:Integer})
+    if !isempty(r) && !(1 ≤ first(r) && last(r) ≤ endof(buf))
+        throw(BoundsError(buf, r))
+    end
+end
+
 function bufferptr(buf::Buffer)
     return pointer(buf.data, buf.bufferpos)
 end

test/runtests.jl

@@ -64,8 +64,10 @@ using Base.Test
     @test endof(s.state.buffer1) == 2
     @test s.state.buffer1[1] === UInt8('a')
     @test s.state.buffer1[2] === UInt8('z')
+    @test s.state.buffer1[1:2] == b"az"
     @test_throws BoundsError s.state.buffer1[0]
     @test_throws BoundsError s.state.buffer1[3]
+    @test_throws BoundsError s.state.buffer1[3:4]
 end
 
 Pkg.test("CodecZlib")