From 566f8b4e6f980dd280a995b55a2026fff157d3aa Mon Sep 17 00:00:00 2001
From: Jeff Bezanson <jeff.bezanson@gmail.com>
Date: Mon, 30 Jun 2014 15:49:55 -0400
Subject: [PATCH] map() UTF32String to UTF32String, return UTF8String for all
 non-ASCIIString

fixes #7422
---
 base/string.jl |  5 ++++-
 base/utf32.jl  | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/base/string.jl b/base/string.jl
index eb7e8a520735f..9d4ba6ec0f353 100644
--- a/base/string.jl
+++ b/base/string.jl
@@ -790,6 +790,9 @@ end
 
 ## string map, filter, has ##
 
+map_result(s::String, a::Vector{Uint8}) = UTF8String(a)
+map_result(s::Union(ASCIIString,SubString{ASCIIString}), a::Vector{Uint8}) = bytestring(a)
+
 function map(f::Function, s::String)
     out = IOBuffer(Array(Uint8,endof(s)),true,true)
     truncate(out,0)
@@ -800,7 +803,7 @@ function map(f::Function, s::String)
         end
         write(out, c2::Char)
     end
-    takebuf_string(out)
+    map_result(s, takebuf_array(out))
 end
 
 function filter(f::Function, s::String)
diff --git a/base/utf32.jl b/base/utf32.jl
index 1a5aac3ff513c..50bc1d8b0af3f 100644
--- a/base/utf32.jl
+++ b/base/utf32.jl
@@ -96,3 +96,18 @@ function utf32(p::Union(Ptr{Char}, Ptr{Uint32}, Ptr{Int32}))
     while unsafe_load(p, len+1) != 0; len += 1; end
     utf32(p, len)
 end
+
+function map(f::Function, s::UTF32String)
+    d = s.data
+    out = similar(d)
+    out[end] = 0
+
+    for i = 1:(length(d)-1)
+        c2 = f(d[i])
+        if !isa(c2,Char)
+            error("map(f,s::String) requires f to return Char; try map(f,collect(s)) or a comprehension instead")
+        end
+        out[i] = (c2::Char)
+    end
+    UTF32String(out)
+end