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Falling through sort of makes sense in C, which is underdefined by design to allow pulling whatever dirty tricks needed to get where you're going. Copying the

by codr7 7y ago

Falling through sort of makes sense in C, which is underdefined by design to allow pulling whatever dirty tricks needed to get where you're going. Copying the idea to higher level languages makes little sense to me. Blindly copying any feature into a language design is a bad idea from my experience.

rat9988 7y ago
Honestly I'd rather use goto than have fallthrough by default in C. Or even better, a Fallthrough keyword as in GO.
- codr7 7y ago
  Wow, had no idea about fallthrough in Go and I've written plenty. Thanks. That's a seriously ugly solution, but I guess that could be considered a good thing.
- b2gills 7y ago
  Perl6 has a fallthrough keyword named `proceed`. It also has a keyword named `succeed` which is the default for `when` blocks. given 1 { when Int { say 'integer'; proceed } if 0 ≤ $_ ≤ 9 { say 'digit'; succeed } when 1 { say 'one'; proceed } } The above will print two lines `integer` and `digit`. It will not get a chance to run the second `when` block because of the `succeed` that gets run before it. If you want the `given` block to return a value, `succeed` can be given a value. my $result = do given $example { when 1 { 'one' } when 2 { succeed 'two' } # succeed is redundant here if $_ == 3 { succeed 'three' } # acts like a `when` block and returns "three" … } --- Perl6 is “supposed” to have a `goto` keyword, but nobody has implemented it. Mainly because of a lack of need. One of the few good uses of `goto` in a higher level language is to have a portion of a function always run at the function exit. Perl6 has `LEAVE`, `KEEP`, and `UNDO` which handles this nicely. sub foo (){ my $fh = open 'example.txt', :r; LEAVE $fh.close; # close $fh at scope exit … # use the opened file handle } Technically it would probably be better to have the `.close` be conditional on whether the $fh was successfully opened. sub foo (){ my $fh = open 'example.txt', :r; LEAVE with $fh {.close} without $fh {.throw}; # throw the error in `$fh` # (This isn't necessary, as it will get thrown as soon as you use it.) … # use the opened file handle }

by codr7 7y ago

rat9988 7y ago

Honestly I'd rather use goto than have fallthrough by default in C. Or even better, a Fallthrough keyword as in GO.

codr7 7y ago
Wow, had no idea about fallthrough in Go and I've written plenty. Thanks. That's a seriously ugly solution, but I guess that could be considered a good thing.
b2gills 7y ago
Perl6 has a fallthrough keyword named `proceed`. It also has a keyword named `succeed` which is the default for `when` blocks. given 1 { when Int { say 'integer'; proceed } if 0 ≤ $_ ≤ 9 { say 'digit'; succeed } when 1 { say 'one'; proceed } } The above will print two lines `integer` and `digit`. It will not get a chance to run the second `when` block because of the `succeed` that gets run before it. If you want the `given` block to return a value, `succeed` can be given a value. my $result = do given $example { when 1 { 'one' } when 2 { succeed 'two' } # succeed is redundant here if $_ == 3 { succeed 'three' } # acts like a `when` block and returns "three" … } --- Perl6 is “supposed” to have a `goto` keyword, but nobody has implemented it. Mainly because of a lack of need. One of the few good uses of `goto` in a higher level language is to have a portion of a function always run at the function exit. Perl6 has `LEAVE`, `KEEP`, and `UNDO` which handles this nicely. sub foo (){ my $fh = open 'example.txt', :r; LEAVE $fh.close; # close $fh at scope exit … # use the opened file handle } Technically it would probably be better to have the `.close` be conditional on whether the $fh was successfully opened. sub foo (){ my $fh = open 'example.txt', :r; LEAVE with $fh {.close} without $fh {.throw}; # throw the error in `$fh` # (This isn't necessary, as it will get thrown as soon as you use it.) … # use the opened file handle }