On Thursday, 7 March 2013 at 16:12:09 UTC, bioinfornatics wrote:
On Thursday, 7 March 2013 at 13:37:56 UTC, lomereiter wrote:
The second is probably faster (with optimizations enabled),
because each call to writeln incurs overhead of
locking/unlocking the file stream (which is stdout in this
case).
If you need to print huge amounts of data, use
lockingTextWriter like this:
auto w = stdout.lockingTextWriter;
foreach (i; 0 .. 5) {
w.put("sometext\n");
w.formattedwrite("%d\n", some_number);
}
However, std.format.formattedWrite is also relatively slow, so
it's better to prepare string representation of an object in a
buffer on the stack - say, with snprintf, or your own set of
formatting functions - and then put it into the writer.
On Thursday, 7 March 2013 at 10:04:34 UTC, bioinfornatics
wrote:
Dear,
little question when writing to a file 5 "hello" lines (by
example)
I would like to know if they are a difference between:
writeln( "hello" ); x5
and:
string[] helloList = [
"hello","hello","hello","hello","hello"];
writeln( helloList.join( newline) );
I mean if one way is more efficient by speed?
and if is not stdout but File ?
thanks a lot that is really interesting
I only replace write by put and do this:
auto output = File( f.absolutePath().expandTilde(), "w"
).lockingTextWriter();
that build without get an error but at runtime i got:
std.exception.ErrnoException@/env/export/nfs2/cns_prog/opt/gdc/include/d/4.7.2/std/stdio.d(1267):
(Bad file descriptor)
