Merge pull request #12224 from malmaud/str_replace

Re-add faster `replace`

base/strings/util.jl

@@ -173,7 +173,10 @@ function _rsplit{T<:AbstractString,U<:Array}(str::T, splitter, limit::Integer, k
 end
 #rsplit(str::AbstractString) = rsplit(str, _default_delims, 0, false)
 
-function replace(str::ByteString, pattern, repl::Function, limit::Integer)
+_replacement(repl, str, j, k) = repl
+_replacement(repl::Function, str, j, k) = repl(SubString(str, j, k))
+
+function replace(str::ByteString, pattern, repl, limit::Integer)
     n = 1
     e = endof(str)
     i = a = start(str)
@@ -182,8 +185,8 @@ function replace(str::ByteString, pattern, repl::Function, limit::Integer)
     out = IOBuffer()
     while j != 0
         if i == a || i <= k
-            write(out, SubString(str,i,prevind(str,j)))
-            write(out, string(repl(SubString(str,j,k))))
+            write_sub(out, str.data, i, j-i)
+            write(out, _replacement(repl, str, j, k))
         end
         if k<j
             i = j
@@ -202,8 +205,7 @@ function replace(str::ByteString, pattern, repl::Function, limit::Integer)
     write(out, SubString(str,i))
     takebuf_string(out)
 end
-replace(s::AbstractString, pat, f::Function, n::Integer) = replace(bytestring(s), pat, f, n)
-replace(s::AbstractString, pat, r, n::Integer) = replace(s, pat, x->r, n)
+replace(s::AbstractString, pat, f, n::Integer) = replace(bytestring(s), pat, f, n)
 replace(s::AbstractString, pat, r) = replace(s, pat, r, 0)
 
 # hex <-> bytes conversion