My First Pugs Test

Ovid on 2006-12-17T23:21:12

I've had commit access to the Pugs project for a long time but haven't done much with it. I fixed some stuff in CGI, wrote the first translation of HTML::Entities and started the examples/cookbook project (largely untouched), but that was about it. Today, in trying to solve 99 Perl 6 problems, I ran into a bug.

my @array = ;
@array.splice(3, 5).perl.say;

That prints 'h', instead of of the list. I hopped onto the #perl6 IRC channel and asked about this and Luke found the problem in src/Pugs/Primhs:

-- op4 "splice" = \x y z w-> do
op4 "splice" = \x y z w -> do
    splice  <- doArray x array_splice
    start   <- fromVal y
    count   <- fromVal z
    vals    <- fromVals w
    vals'   <- splice start count vals
    ifListContext
        (return $ VList vals')
        (return $ last (undef:vals'))

The ifListContext says that if we're in list context, return the list, otherwise, return the last value from it. He changed that to this:

-- op4 "splice" = \x y z w-> do
op4 "splice" = \x y z w -> do
    splice  <- doArray x array_splice
    start   <- fromVal y
    count   <- fromVal z
    vals    <- fromVals w
    vals'   <- splice start count vals
    return $ VList vals'

I then committed a test to verify that this works. I really want to learn Haskell so I can do this myself, but for now, I'll keep working on my 99 problems.