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Postings from March 2022
I have a question. What means the scalar value is created as a number for JSON serialization? # Created as a number my $num = 0; # Replace 0 with "0" $num =~ s/0/0/; # Is this result 0 or "0"? my $json_num = to_json $num; 2022-2-24 7:03 Graham Knop <haarg@haarg.org> wrote: > After the merge of https://github.com/Perl/perl5/pull/18958, it is > possible to reliably distinguish between values that started as > numbers vs values that started as strings. Essentially, if the POK > flag is set, the value started as a string. If the POK flag is not set > and IOK or NOK is set, it started as a number. These flags can be > checked in XS, or via the B module, but cannot currently be checked in > pure perl. For serializers, being able to detect the original type of > a value is essential, so it would help to provide functions to provide > this information. For example, providing builtin::isnumber and > builtin::isstring, to go along with builtin::isbool. > > This does potentially have a huge impact on the language as a whole. > While this is needed for serializers, providing easy access to this > type data will pretty much inevitably result in people using the > functions within perl for things like parameter validation. The values > "2" and 2 are meant to be fully interchangeable inside perl, and new > code distinguishing them will break many expectations. > > Even with caveats, I do think this is something that the language > should provide. I am uncertain on the naming of the functions. > builtin::isnumber and builtin::isstring are perhaps the most > obvious, but they also imply that distinguishing these types is a > normal thing to do. We may want the function names to be more > opinionated, implying more strongly that they are meant to be used for > things like serialization, not internal type checking. That feels like > a losing battle though once any function of this type is available. >Thread Previous | Thread Next