Missing first arg in list causes error

[Jacqui Caren]

Paul Makepeace wrote:
> This just bit me,
> 
>   $ perl -le 'print [,"",,]'
>   syntax error at -e line 1, near "[,"
>   Execution of -e aborted due to compilation errors.
>   $ perl -le 'print ["",,,]'
>   ARRAY(0x814ac28)
>   $
> 
> Why does the first one fail?
> 
> Paul

Because '',,, is consumed in list context into ('')

Try perl -de 1
   DB<12> x ['',,,,]
0  ARRAY(0x8355568)
    0  ''
   DB<13>

Because [,''] is a typo and perl reports this (IMHO a good thing).
it will fail to compile.

   DB<7> x [,'']
   syntax error at (eval 10)[/usr/lib/perl5/5.8.1/perl5db.pl:618] line 2,
   near "[,"

but [(),''] or [undef,''] are valid.

   DB<14> x [(),'']
    0  ARRAY(0x8395d80)
      0  ''
   DB<15> x [undef,'']
    0  ARRAY(0x835555c)
      0  undef
      1  ''
   DB<16>


Jacqui