On 05/15/2012 10:42 AM, dcoder wrote:
On Monday, 14 May 2012 at 09:00:14 UTC, simendsjo wrote:
On Mon, 14 May 2012 10:41:54 +0200, Christian Köstlin
<[email protected]> wrote:
Hi,
i wanted to output an ascii-file line by line, but reversed.
the idea was to open the file, use byLine to read it line-by-line,
make this range an array, and retro this array.
But when i convert byLine to an array, the result is already trash.
Please see this snippet.
import std.stdio;
import std.array;
int main(string[] args) {
if (args.length != 2) {
throw new Exception("Usage: " ~ args[0] ~ " file1");
}
auto f = File(args[1], "r");
auto i = array(f.byLine());
foreach (l; i) {
writeln(l);
}
return 0;
}
Any idea why this happens?
regards
christian köstlin
I believe byLine reuses the internal buffer. Try duping the lines:
auto i = f.byLine().map!"a.idup"().array();
Can someone please explain to me the last line?
I'm trying to learn D, by playing with code and reading this forum. I'm
a slow learner. :)
Anyways, I looked at std.stdio code and noticed that byLine resturns a
struct ByLine, but where does the .map come from? Thanks!
It comes from std.algorithm. What that line does is:
f.byLine() // Get by lines, exactly as you know already
.map!"a.idup"() // Iterate over the byLine, and make a Range of
immutable strings with the same contents as each line.
.array() // Convert it from a range to an array of strings
This is achieved through templates accepting strings at compile time to
be somewhat like lambda functions, and UFCS.
