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    <p>I'm also seeing <code>tr///</code> get relatively slower as the line lengths increase although the effect isn't as dramatic. These results are from ActivePerl 5.10.1 (32-bit) on Windows 7 x64. I also got "too few iterations for a reliable count" warnings at 100 so I bumped the iterations up to 500.</p> <pre><code> VL: 4501.06 288 LO: 749.25 29 SH: 69.38 6 VA: 104.66 55 Rate VL-$count VL-$. VL-tr VL-s VL-wc VL-$count 2.82/s -- -0% -52% -56% -99% VL-$. 2.83/s 0% -- -51% -56% -99% VL-tr 5.83/s 107% 106% -- -10% -99% VL-s 6.45/s 129% 128% 11% -- -99% VL-wc 501/s 17655% 17602% 8490% 7656% -- Rate LO-$count LO-$. LO-s LO-tr LO-wc LO-$count 16.5/s -- -1% -50% -51% -97% LO-$. 16.8/s 1% -- -50% -51% -97% LO-s 33.2/s 101% 98% -- -3% -94% LO-tr 34.1/s 106% 103% 3% -- -94% LO-wc 583/s 3424% 3374% 1655% 1609% -- Rate SH-$count SH-$. SH-s SH-tr SH-wc SH-$count 120/s -- -7% -31% -67% -81% SH-$. 129/s 7% -- -26% -65% -80% SH-s 174/s 45% 35% -- -52% -73% SH-tr 364/s 202% 182% 109% -- -43% SH-wc 642/s 433% 397% 269% 76% -- Rate VA-$count VA-$. VA-s VA-tr VA-wc VA-$count 92.6/s -- -5% -36% -63% -79% VA-$. 97.4/s 5% -- -33% -61% -78% VA-s 146/s 57% 50% -- -42% -67% VA-tr 252/s 172% 159% 73% -- -43% VA-wc 439/s 374% 351% 201% 74% -- </code></pre> <p><strong>Edit:</strong> I did a revised benchmark to compare the rates for different line lengths. It clearly shows that <code>tr///</code> starts out with a big advantage for short lines that rapidly disappears as the lines grow longer. As for <em>why</em> this happens, I can only speculate that <code>tr///</code> is optimized for short strings.</p> <p><a href="http://img69.imageshack.us/i/linecount.png/" rel="nofollow noreferrer">Line count rate comparison http://img69.imageshack.us/img69/6250/linecount.th.png</a></p>
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    1. POWhy does Perl's tr/\n// get slower and slower as line lengths increase?
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    1. USMichael Carman
    1. USMichael Carman
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    1. CORemember that tr/// should be operating on the same sized strings since its getting input from sysread in 4096 byte chunks, just that the lines in that string are different lengths.
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      1. USbrian d foy
 

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