UTF-8 scanURIEscapes.

This commit is contained in:
Ferdinand Majerech 2014-07-29 03:10:51 +02:00
parent 1cc07c263a
commit 2003a950cb

View file

@ -2020,6 +2020,83 @@ final class Scanner
assert(false, "Unexpected exception in scanURIEscapesToSlice"); assert(false, "Unexpected exception in scanURIEscapesToSlice");
} }
} }
void scanURIEscapesToSlice8(string name)(const Mark startMark)
@system pure nothrow // @nogc
{
// URI escapes encode a UTF-8 string. We store UTF-8 code units here for
// decoding into UTF-32.
char[4] bytes;
size_t bytesUsed;
Mark mark = reader_.mark;
// Get one dchar by decoding data from bytes.
//
// This is probably slow, but simple and URI escapes are extremely uncommon
// in YAML.
static size_t getDchar(char[] bytes, Reader reader_)
{
import std.utf;
size_t nextChar;
const c = std.utf.decode(bytes[], nextChar);
reader_.sliceBuilder8.write(c);
if(bytes.length - nextChar > 0)
{
core.stdc.string.memmove(bytes.ptr, bytes.ptr + nextChar,
bytes.length - nextChar);
}
return bytes.length - nextChar;
}
enum contextMsg = "While scanning a " ~ name;
try
{
while(reader_.peek() == '%')
{
reader_.forward();
if(bytesUsed == bytes.length)
{
bytesUsed = getDchar(bytes[], reader_);
}
char b = 0;
uint mult = 16;
// Converting 2 hexadecimal digits to a byte.
foreach(k; 0 .. 2)
{
const dchar c = reader_.peek(k);
if(!c.isHexDigit)
{
auto msg = expected("URI escape sequence of 2 hexadecimal "
"numbers", c);
error(contextMsg, startMark, msg, reader_.mark);
return;
}
uint digit;
if(c - '0' < 10) { digit = c - '0'; }
else if(c - 'A' < 6) { digit = c - 'A'; }
else if(c - 'a' < 6) { digit = c - 'a'; }
else { assert(false); }
b += mult * digit;
mult /= 16;
}
bytes[bytesUsed++] = b;
reader_.forward(2);
}
bytesUsed = getDchar(bytes[0 .. bytesUsed], reader_);
}
catch(UTFException e)
{
error(contextMsg, startMark, e.msg, mark);
return;
}
catch(Exception e)
{
assert(false, "Unexpected exception in scanURIEscapesToSlice");
}
}
/// Scan a line break, if any. /// Scan a line break, if any.