how to be faster than perl?

[Derek Parnell]

On Tue, 30 Jan 2007 13:21:53 +0100, Boris Bukowski wrote:

> currently I am testing D for log processing.
> My perl script is more than ten times faster than my D Prog.
> How can I get Lines faster from a File?

Your example code seemed to be trying to count the number of times a
certain string occurred in a file so I didn't bother with working with
'lines' as such. Anyhow, here is one way to do it...

// findtext.d ---------
private import std.file;
private import std.stdio;
private import std.string;

void main (char[][] args) {
        char[] lFileText; // Buffer for file contents.

        int lCnt;   // Number if hits
        int lPos;   // Found at position, or Not Found flag.
        int lFrom;  // Where in the file to look from.

        // Grab the whole file into RAM
        lFileText = cast(char[]) std.file.read(args[1]);

        // Start scanning for the substring.
        lFrom = 0;
        while(lFrom < lFileText.length)
        {
            lPos = std.string.find(lFileText[lFrom..$], args[2]);
            if (lPos != -1)
            {
                // Adjust next starting position.
                lFrom += lPos + args[2].length;
                // And count the hits, of course.
                lCnt++;
            }
            else
            {
                // Force end of scanning.
                lFrom = lFileText.length;
            }
        }

        writefln("Count of '%s' found in '%s': %d",
                        args[2], args[1], lCnt);
}

-- 
Derek
(skype: derek.j.parnell)
Melbourne, Australia
"Down with mediocrity!"
31/01/2007 7:18:25 PM