On 03/15/2011 11:33 PM, Ali Çehreli wrote:
Given that the input stream is UTF-8, it is understandable that the following
program pulls just one code unit from the standard input (I think the console
encoding is UTF-8 on my Ubuntu 10.10):
import std.stdio;
void main()
{
char code;
readf(" %s", &code);
writeln(code); // <-- may write an incomplete character
}
ö is represented by two bytes in the UTF-8 encoding. When ö is fed to the input
of the program, writeln expression does not produce a complete character on the
output. That's understandable with char.
Would you expect all of the bytes to be consumed when a dchar was used instead?
import std.stdio;
void main()
{
dchar code; // <-- now a dchar
readf(" %s", &code);
writeln(code); // <-- BUG: uses a code unit as a code point!
}
Well, when I try to run that bit of code, I get an error in std.format.
formattedRead (line near the end, marked with "***" below).
void formattedRead(R, Char, S...)(ref R r, const(Char)[] fmt, S args)
{
auto spec = FormatSpec!Char(fmt);
static if (!S.length)
{
spec.readUpToNextSpec(r);
enforce(spec.trailing.empty);
}
else
{
// The function below accounts for '*' == fields meant to be
// read and skipped
void skipUnstoredFields()
{
for (;;)
{
spec.readUpToNextSpec(r);
if (spec.width != spec.DYNAMIC) break;
// must skip this field
skipData(r, spec);
}
}
skipUnstoredFields();
alias typeof(*args[0]) A;
static if (isTuple!A)
{
foreach (i, T; A.Types)
{
//writeln("Parsing ", r, " with format ", fmt);
(*args[0])[i] = unformatValue!(T)(r, spec);
skipUnstoredFields();
}
}
else
{
*args[0] = unformatValue!(A)(r, spec); // ***
}
return formattedRead(r, spec.trailing, args[1 .. $]);
}
}
When the input is ö, now the output becomes Ã.
What would you expect to happen?
I would expect a whole code representing 'ö'.
Ali
P.S. As what is written is not the same as what is read above, I am reminded of
another issue: would you expect the strings "false" and "true" to be accepted
as correct inputs when readf'ed to bool variables?
Yep!
Denis
--
_________________
vita es estrany
spir.wikidot.com
