Add show() for StringEncoder/StringDecoder

Author: nalimilan

src/StringEncodings.jl

@@ -81,7 +81,7 @@ end
 
 const BUFSIZE = 100
 
-type StringEncoder{S<:IO} <: IO
+type StringEncoder{F<:Encoding, T<:Encoding, S<:IO} <: IO
     ostream::S
     closestream::Bool
     cd::Ptr{Void}
@@ -93,7 +93,7 @@ type StringEncoder{S<:IO} <: IO
     outbytesleft::Ref{Csize_t}
 end
 
-type StringDecoder{S<:IO} <: IO
+type StringDecoder{F<:Encoding, T<:Encoding, S<:IO} <: IO
     istream::S
     closestream::Bool
     cd::Ptr{Void}
@@ -190,7 +190,8 @@ function StringEncoder(ostream::IO, to::Encoding, from::Encoding=enc"UTF-8")
     cd = iconv_open(ASCIIString(to), ASCIIString(from))
     inbuf = Vector{UInt8}(BUFSIZE)
     outbuf = Vector{UInt8}(BUFSIZE)
-    s = StringEncoder(ostream, false, cd, inbuf, outbuf,
+    s = StringEncoder{typeof(from), typeof(to), typeof(ostream)}(ostream, false,
+                      cd, inbuf, outbuf,
                       Ref{Ptr{UInt8}}(pointer(inbuf)), Ref{Ptr{UInt8}}(pointer(outbuf)),
                       Ref{Csize_t}(0), Ref{Csize_t}(BUFSIZE))
     finalizer(s, finalize)
@@ -202,6 +203,12 @@ StringEncoder(ostream::IO, to::AbstractString, from::Encoding=enc"UTF-8") =
 StringEncoder(ostream::IO, to::AbstractString, from::AbstractString) =
     StringEncoder(ostream, Encoding(to), Encoding(from))
 
+function show{F, T, S}(io::IO, s::StringEncoder{F, T, S})
+    from = F()
+    to = T()
+    print(io, "StringEncoder{$from, $to}($(s.ostream))")
+end
+
 # Flush input buffer and convert it into output buffer
 # Returns the number of bytes written to output buffer
 function flush(s::StringEncoder)
@@ -256,7 +263,8 @@ function StringDecoder(istream::IO, from::Encoding, to::Encoding=enc"UTF-8")
     cd = iconv_open(ASCIIString(to), ASCIIString(from))
     inbuf = Vector{UInt8}(BUFSIZE)
     outbuf = Vector{UInt8}(BUFSIZE)
-    s = StringDecoder(istream, false, cd, inbuf, outbuf,
+    s = StringDecoder{typeof(from), typeof(to), typeof(istream)}(istream, false,
+                      cd, inbuf, outbuf,
                       Ref{Ptr{UInt8}}(pointer(inbuf)), Ref{Ptr{UInt8}}(pointer(outbuf)),
                       Ref{Csize_t}(0), Ref{Csize_t}(BUFSIZE), 0)
     finalizer(s, finalize)
@@ -268,6 +276,12 @@ StringDecoder(istream::IO, from::AbstractString, to::Encoding=enc"UTF-8") =
 StringDecoder(istream::IO, from::AbstractString, to::AbstractString) =
     StringDecoder(istream, Encoding(from), Encoding(to))
 
+function show{F, T, S}(io::IO, s::StringDecoder{F, T, S})
+    from = F()
+    to = T()
+    print(io, "StringDecoder{$from, $to}($(s.istream))")
+end
+
 # Fill input buffer and convert it into output buffer
 # Returns the number of bytes written to output buffer
 function fill_buffer!(s::StringDecoder)

test/runtests.jl

@@ -34,7 +34,9 @@ let s = "a string チャネルパートナーの選択"
     write(p, s.data)
     close(p)
 
-    p = StringEncoder(IOBuffer(), "UTF-16LE")
+    b = IOBuffer()
+    p = StringEncoder(b, "UTF-16LE")
+    @test string(p) == "StringEncoder{UTF-8, UTF-16LE}($(string(b)))"
     write(p, s.data[1:10])
     @test_throws IncompleteSequenceError close(p)
 
@@ -50,7 +52,9 @@ let s = "a string チャネルパートナーの選択"
         @test takebuf_string(io) == "Incomplete byte sequence at end of input"
     end
 
-    p = StringDecoder(IOBuffer(encode(s, "UTF-16LE")[1:19]), "UTF-16LE")
+    b = IOBuffer(encode(s, "UTF-16LE")[1:19])
+    p = StringDecoder(b, "UTF-16LE")
+    @test string(p) == "StringDecoder{UTF-16LE, UTF-8}($(string(b)))"
     @test readstring(p) == s[1:9]
     @test_throws IncompleteSequenceError close(p)
 
@@ -59,7 +63,8 @@ let s = "a string チャネルパートナーの選択"
     x = encode(s, "ISO-2022-JP")
     @test decode(x, "ISO-2022-JP") == s
 
-    p = StringDecoder(IOBuffer(x), "ISO-2022-JP", "UTF-8")
+    p = StringDecoder(b, "ISO-2022-JP", "UTF-8")
+    b = IOBuffer(x)
     # Test that closed pipe behaves correctly
     close(p)
     @test eof(p)