Re^2: A plague on all your features

$VAR1 = {
          'a' => undef,
          'b' => {
                   'feature_bareword_filehandles' => 1,
                   'feature_indirect' => 1,
                   'feature_multidimensional' => 1,
                   'feature_say' => 1,
                   'feature_state' => 1,
                   'feature_switch' => 1
                 },
          'c' => undef,
          'd' => {
                   'feature_bareword_filehandles' => 1,
                   'feature_indirect' => 1,
                   'feature_multidimensional' => 1,
                   'feature_say' => 1,
                   'feature_state' => 1,
                   'feature_switch' => 1
                 },
          'e' => {
                   'feature_bareword_filehandles' => 1,
                   'feature_indirect' => 1,
                   'feature_multidimensional' => 1,
                   'feature_say' => 1
                 },
          'f' => {
                   'feature_bareword_filehandles' => 1,
                   'feature_indirect' => 1,
                   'feature_multidimensional' => 1
                 },
          'g' => {
                   'feature_bareword_filehandles' => 1,
                   'feature_indirect' => 1,
                   'feature_multidimensional' => 1
                 }
        };
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Comment on Re^2: A plague on all your features Download Code

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Re^3: A plague on all your features by ikegami (Patriarch) on Mar 07, 2023 at 00:58 UTC
I don't know why the hints are undef for `c`, but I can confirm it's accurate. `$ diff -u \ <( perl -MO=Concise,b b.pl 2>&1 ) \ <( perl -MO=Concise,c b.pl 2>&1 ) --- /dev/fd/63 2023-03-06 20:59:39.932888013 -0400 +++ /dev/fd/62 2023-03-06 20:59:39.932888013 -0400 @@ -1,8 +1,8 @@ b.pl syntax OK -main::b: +main::c: 5 <1> leavesub[1 ref] K/REFC,1 ->(end) - <@> lineseq KP ->5 -1 <;> nextstate(main 1252 b.pl:15) v:%,,&,x,x&,x$,fea=15 ->2 +1 <;> nextstate(main 1257 b.pl:16) v:,&,x,x&,x$,fea=1 ->2 4 <1> entersub KS ->5 - <1> ex-list K ->4 2 <0> pushmark s ->3` [download] Note the different value of the hints (`fea=` for "feature") for the two lines.	[reply] [d/l] [select]
Re^4: A plague on all your features by ikegami (Patriarch) on Mar 07, 2023 at 01:04 UTC
Actually, the whole `v:` thing is the hints, not just the `fea=` portion. And we see another difference: The `%`. Not sure what it means, but it relates to `%^H`. Presumably the presence of `%^H`. Again, present for `b` but not `c`.	[reply] [d/l] [select]
Re^5: A plague on all your features by ikegami (Patriarch) on Mar 07, 2023 at 01:17 UTC
`b` has a `%^H` and `c` doesn't. The extra time spent is clearly spent accessing (copying?) this hash. Why doesn't `c` have a `%^H`? Some hints are found in `$^H` and some are in `%^H`. I think what's happening is that `use 5.010;` avoids creating `%^H` just to set flags that are on by default (such as `indirect`). `use feature ":5:10";`, on the other hand, clearly does create this hash. There's a problem with this answer. `say` and a couple other flags which aren't set by default appear to be in `%^H`. Maybe they are found in both `$^H` and `%^H`?	[reply] [d/l] [select]