Re: [RFC] Short-match

> Le 17 déc. 2020 à 17:23, Sara Golemon <pollita@php.net> a écrit : > > On Wed, Dec 16, 2020 at 6:50 PM someniatko <someniatko@gmail.com> wrote: >> >> match is an expression, where as if-else construction is >> not. This >> allows for combining it with a potential future feature of single line >> functions and methods. For example (hypothetical syntax is used): >> >> ``` >> $getNumber = fn(int $number) => match { >> $number < 0 => NumberKind::NEGATIVE, >> $number == 0 => NumberKind::ZERO, >> $number > 0 => NumberKind::POSITIVE, >> }; >> ``` >> > > That does read attractively, yes. This is the example that should have > been offered first as it shows the expression nature shining. > > To contrast that with what would be possible now in an expressive > functional form: > > $getNumber = fn(int $number) => [ > -1 => NumberKind::NEGATIVE, > 0 => NumberKind::ZERO, > 1 => NumberKind::POSITIVE, > ][$number <=> 0]; > > The match form *certainly* reads more naturally than the spaceship indexing > form even though both take up equal space. > > -Sara If you mean a version of if that works in expressions, there already exists a standard operator for that. Once its historical associativity goof is definitely fixed, you will be able to write: ``` $getNumberKind = fn(int $number) => $number > 0 ? NumberKind::POSITIVE : $number == 0 ? NumberKind::ZERO : $number < 0 ? NumberKind::NEGATIVE : throw new \TypeError; ``` There is a semantic advantage of match over ? : , though, namely its exhaustivity: You don’t need to add a “panic” default case in order to catch logic errors. —Claude