Re^2: Confused by RegEx count

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Re^3: Confused by RegEx count by choroba (Cardinal) on Feb 21, 2024 at 09:23 UTC
Interestingly, on my machine: `Rate length_subst match subst trans +literation length_subst 2864/s -- -89% -90% + -97% match 25687/s 797% -- -13% + -74% subst 29356/s 925% 14% -- + -70% transliteration 98682/s 3346% 284% 236% + --` [download] `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l] [select]
Re^4: Confused by RegEx count by hippo (Archbishop) on Feb 21, 2024 at 09:55 UTC
That's rather counter-intuitive. Just ran them myself and for me, match beats subst: `Rate length_subst subst match trans +literation length_subst 2080/s -- -88% -90% + -97% subst 17998/s 765% -- -16% + -77% match 21423/s 930% 19% -- + -72% transliteration 76797/s 3592% 327% 258% + --` [download] This is perl 5, version 34, subversion 0 (v5.34.0) built for x86_64-linux-thread-multi. 🦛	[reply] [d/l]
Re^5: Confused by RegEx count by Danny (Chaplain) on Feb 21, 2024 at 11:41 UTC
Yet another data point with cygwin, everything updated 2/21/24. Rate length_subst subst transliteration length_subst 6174/s -- -92% -98% subst 79622/s 1190% -- -78% transliteration 355231/s 5654% 346% --	[reply]
Re^5: Confused by RegEx count by choroba (Cardinal) on Feb 22, 2024 at 10:09 UTC
Yes, I'm getting similar results in 5.39.6, but in 5.26.1, the substitution is faster. `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l]
Re^4: Confused by RegEx count by NERDVANA (Priest) on Feb 22, 2024 at 06:17 UTC
I get results like hippo's with perl 5.36 on a recent AMD Ryzen `Rate length_subst subst match trans +literation length_subst 8970/s -- -89% -91% + -97% subst 78884/s 779% -- -19% + -78% match 97126/s 983% 23% -- + -73% transliteration 355019/s 3858% 350% 266% + --` [download] Though, depending how many matches there are, does perl have to assemble a stack of N elements (copying each character into its own scalar) before assigning the list to the scalar to get the count? With the subst, the right optimizations could allow it to update that one character without changing the length of the string or copying anything, so it could be fast, and then doesn't need to assemble a list of the matches.	[reply] [d/l]

                   Rate length_subst         match         subst trans
+literation
length_subst     2864/s           --          -89%          -90%      
+      -97%
match           25687/s         797%            --          -13%      
+      -74%
subst           29356/s         925%           14%            --      
+      -70%
transliteration 98682/s        3346%          284%          236%      
+        --
[download]

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

[reply]
[d/l]
[select]

That's rather counter-intuitive. Just ran them myself and for me, match beats subst:

                   Rate length_subst         subst         match trans
+literation
length_subst     2080/s           --          -88%          -90%      
+      -97%
subst           17998/s         765%            --          -16%      
+      -77%
match           21423/s         930%           19%            --      
+      -72%
transliteration 76797/s        3592%          327%          258%      
+        --
[download]

This is perl 5, version 34, subversion 0 (v5.34.0) built for x86_64-linux-thread-multi.

🦛

[reply]
[d/l]

                    Rate    length_subst           subst transliteration
length_subst      6174/s              --            -92%            -98%
subst            79622/s           1190%              --            -78%
transliteration 355231/s           5654%            346%              --

[reply]

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

[reply]
[d/l]

                    Rate length_subst         subst        match trans
+literation
length_subst      8970/s           --          -89%         -91%      
+      -97%
subst            78884/s         779%            --         -19%      
+      -78%
match            97126/s         983%           23%           --      
+      -73%
transliteration 355019/s        3858%          350%         266%      
+        --
[download]

Though, depending how many matches there are, does perl have to assemble a stack of N elements (copying each character into its own scalar) before assigning the list to the scalar to get the count? With the subst, the right optimizations could allow it to update that one character without changing the length of the string or copying anything, so it could be fast, and then doesn't need to assemble a list of the matches.

[reply]
[d/l]