John H. Robinson, IV wrote:
Andrew Lentvorski wrote:
Also, Perl needs to suck it up and put named groups in its regex engine.
What is the benefit of:
(?P<id>[a-zA-Z_]\w*) m.group('id')
over
([a-zA-Z_]\w*) $1
?
Why do so many Perl subroutines use named parameters rather than
positional parameters?
Code maintenance.
Take a recursive descent parser, for instance. If I need to add another
token in the middle or adjust the grammar rules, the tokens all
rearrange which positional group they fall into.
It's simply an extension of the DRY (Don't Repeat Yourself) principle.
With the named parameter, the match and the match name are encoded
together once. With the Perl version, the match/match name mapping are
encoded twice--once in the regex and once in whatever pulls apart the
positional parameters.
-a
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