Base.transcode to replace utf8to16 and utf16to8

base/c.jl

@@ -106,13 +106,15 @@ if is_windows()
 function cwstring(s::AbstractString)
     bytes = String(s).data
     0 in bytes && throw(ArgumentError("embedded NULs are not allowed in C strings: $(repr(s))"))
-    return push!(utf8to16(bytes), 0)
+    return push!(transcode(UInt16, bytes), 0)
 end
 end
 
-# conversions between UTF-8 and UTF-16 for Windows APIs
+# transcoding between data in UTF-8 and UTF-16 for Windows APIs
 
-function utf8to16(src::Vector{UInt8})
+transcode{T<:Union{UInt8,UInt16}}(::Type{T}, src::Vector{T}) = src
+
+function transcode(::Type{UInt16}, src::Vector{UInt8})
     dst = UInt16[]
     i, n = 1, length(src)
     n > 0 || return dst
@@ -162,7 +164,7 @@ function utf8to16(src::Vector{UInt8})
     return dst
 end
 
-function utf16to8(src::Vector{UInt16})
+function transcode(::Type{UInt8}, src::Vector{UInt16})
     dst = UInt8[]
     i, n = 1, length(src)
     n > 0 || return dst

base/env.jl

@@ -19,7 +19,7 @@ function access_env(onError::Function, str::AbstractString)
         error(string("getenv: ", str, ' ', len, "-1 != ", ret, ": ", Libc.FormatMessage()))
     end
     pop!(val) # NUL
-    return String(utf16to8(val))
+    return String(transcode(UInt8, val))
 end
 
 function _setenv(svar::AbstractString, sval::AbstractString, overwrite::Bool=true)
@@ -97,7 +97,7 @@ function next(hash::EnvHash, block::Tuple{Ptr{UInt16},Ptr{UInt16}})
     len = ccall(:wcslen, UInt, (Ptr{UInt16},), pos)
     buf = Array{UInt16}(len)
     unsafe_copy!(pointer(buf), pos, len)
-    env = String(utf16to8(buf))
+    env = String(transcode(UInt8, buf))
     m = match(r"^(=?[^=]+)=(.*)$"s, env)
     if m === nothing
         error("malformed environment entry: $env")

base/file.jl

@@ -203,7 +203,7 @@ function tempdir()
         error("GetTempPath failed: $(Libc.FormatMessage())")
     end
     resize!(temppath,lentemppath)
-    return String(utf16to8(temppath))
+    return String(transcode(UInt8, temppath))
 end
 tempname(uunique::UInt32=UInt32(0)) = tempname(tempdir(), uunique)
 const temp_prefix = cwstring("jl_")
@@ -216,7 +216,7 @@ function tempname(temppath::AbstractString,uunique::UInt32)
         error("GetTempFileName failed: $(Libc.FormatMessage())")
     end
     resize!(tname,lentname)
-    return String(utf16to8(tname))
+    return String(transcode(UInt8, tname))
 end
 function mktemp(parent=tempdir())
     filename = tempname(parent, UInt32(0))

base/filesystem.jl

@@ -42,8 +42,8 @@ export File,
 import Base:
     UVError, _sizeof_uv_fs, check_open, close, eof, eventloop, fd, isopen,
     nb_available, position, read, read!, readavailable, seek, seekend, show,
-    skip, stat, unsafe_read, unsafe_write, utf16to8, utf8to16, uv_error,
-    uvhandle, uvtype, write
+    skip, stat, unsafe_read, unsafe_write, transcode, uv_error, uvhandle,
+    uvtype, write
 
 if is_windows()
     import Base: cwstring

base/interactiveutil.jl

@@ -150,7 +150,7 @@ elseif is_windows()
         len = 0
         while unsafe_load(plock, len+1) != 0; len += 1; end
         # get Vector{UInt16}, transcode data to UTF-8, make a String of it
-        s = String(utf16to8(unsafe_wrap(Array, plock, len)))
+        s = String(transcode(UInt8, unsafe_wrap(Array, plock, len)))
         systemerror(:GlobalUnlock, 0==ccall((:GlobalUnlock, "kernel32"), stdcall, Cint, (Ptr{UInt16},), plock))
         return s
     end

base/libc.jl

@@ -2,14 +2,14 @@
 
 module Libc
 
+import Base: transcode
+
 export FILE, TmStruct, strftime, strptime, getpid, gethostname, free, malloc, calloc, realloc,
-    errno, strerror, flush_cstdio, systemsleep, time
+    errno, strerror, flush_cstdio, systemsleep, time, transcode
 if is_windows()
     export GetLastError, FormatMessage
 end
 
-import Base: utf16to8
-
 include(string(length(Core.ARGS)>=2?Core.ARGS[2]:"","errno_h.jl"))  # include($BUILDROOT/base/errno_h.jl)
 
 ## RawFD ##
@@ -277,7 +277,7 @@ if is_windows()
         buf = Array{UInt16}(len)
         unsafe_copy!(pointer(buf), p, len)
         ccall(:LocalFree,stdcall,Ptr{Void},(Ptr{Void},),p)
-        return String(utf16to8(buf))
+        return String(transcode(UInt8, buf))
     end
 end
 

base/path.jl

@@ -136,7 +136,7 @@ function realpath(path::AbstractString)
         systemerror(:realpath, n == 0)
         x = n < length(buf) # is the buffer big enough?
         resize!(buf, n) # shrink if x, grow if !x
-        x && return String(utf16to8(buf))
+        x && return String(transcode(UInt8, buf))
     end
 end
 
@@ -150,7 +150,7 @@ function longpath(path::AbstractString)
         systemerror(:longpath, n == 0)
         x = n < length(buf) # is the buffer big enough?
         resize!(buf, n) # shrink if x, grow if !x
-        x && return String(utf16to8(buf))
+        x && return String(transcode(UInt8, buf))
     end
 end
 

test/misc.jl

@@ -209,11 +209,11 @@ whos(IOBuffer(), Tmp14173) # warm up
 @test @allocated(whos(IOBuffer(), Tmp14173)) < 10000
 
 ## test conversion from UTF-8 to UTF-16 (for Windows APIs)
-import Base: utf8to16, utf16to8
+import Base.Libc: transcode
 
 # empty arrays
-@test utf8to16(UInt8[]) == UInt16[]
-@test utf16to8(UInt16[]) == UInt8[]
+@test transcode(UInt16, UInt8[]) == UInt16[]
+@test transcode(UInt8, UInt16[]) == UInt8[]
 
 # UTF-8-like sequences
 V8 = [
@@ -304,15 +304,15 @@ I8 = [(s,map(UInt16,s)) for s in X8]
 
 for (X,Y,Z) in ((V8,V8,V8), (I8,V8,I8), (V8,I8,V8), (V8,V8,I8), (I8,V8,V8))
     for (a8, a16) in X
-        @test utf8to16(a8) == a16
+        @test transcode(UInt16, a8) == a16
         for (b8, b16) in Y
             ab8 = [a8; b8]
             ab16 = [a16; b16]
-            @test utf8to16(ab8) == ab16
+            @test transcode(UInt16, ab8) == ab16
             for (c8, c16) in Z
                 abc8 = [ab8; c8]
                 abc16 = [ab16; c16]
-                @test utf8to16(abc8) == abc16
+                @test transcode(UInt16, abc8) == abc16
             end
         end
     end
@@ -359,18 +359,18 @@ I16 = [
 
 for (X,Y,Z) in ((V16,V16,V16), (I16,V16,I16), (V16,I16,V16), (V16,V16,I16), (I16,V16,V16))
     for (a16, a8) in X
-        @test utf16to8(a16) == a8
-        @test utf8to16(a8) == a16
+        @test transcode(UInt8, a16) == a8
+        @test transcode(UInt16, a8) == a16
         for (b16, b8) in Y
             ab16 = [a16; b16]
             ab8 = [a8; b8]
-            @test utf16to8(ab16) == ab8
-            @test utf8to16(ab8) == ab16
+            @test transcode(UInt8, ab16) == ab8
+            @test transcode(UInt16, ab8) == ab16
             for (c16, c8) in Z
                 abc16 = [ab16; c16]
                 abc8 = [ab8; c8]
-                @test utf16to8(abc16) == abc8
-                @test utf8to16(abc8) == abc16
+                @test transcode(UInt8, abc16) == abc8
+                @test transcode(UInt16, abc8) == abc16
             end
         end
     end