Re: Stringifying undefs

You could play tricks with tie -- I'm not advocating it, but it is a possibility depending upon your purpose.

{ 
    package Undef; 
    sub TIESCALAR{ bless \pop, 'Undef';} 
    sub STORE{ $$_[0] = $_[1]; } 
    sub FETCH{ defined $$_[0] ? $$_[0] : 0 } 
};

tie $x, 'Undef';

$x = 0; print "'$x'";
'0'

$x = ''; print "'$x'";
''

$x = undef; print "'$x'";
'0'
[download]

Examine what is said, not who speaks.

"Efficiency is intelligent laziness." -David Dunham
"Think for yourself!" - Abigail

Comment on Re: Stringifying undefs Download Code

Replies are listed 'Best First'.
Re: Re: Stringifying undefs by ambrus (Abbot) on Mar 02, 2004 at 15:39 UTC
That can help, but you're probably have to redefine the builtins `undef` and `return` because tieing evrything to Undef by hand is not easier then just writing `\|\|0` everywhere. This, however won't help at all if BUU gets the undefs from uninitialized hash or array elements. In that case, you should probably create a tied array/hash that gives 0 for uninitialized elements. (Let me note that you can set what a hash returns instead of an uninitialized element in ruby.)	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re: Re: Stringifying undefs
by ambrus (Abbot) on Mar 02, 2004 at 15:39 UTC

That can help, but you're probably have to redefine the builtins undef and return because tieing evrything to Undef by hand is not easier then just writing ||0 everywhere.

This, however won't help at all if BUU gets the undefs from uninitialized hash or array elements. In that case, you should probably create a tied array/hash that gives 0 for uninitialized elements. (Let me note that you can set what a hash returns instead of an uninitialized element in ruby.)

[reply]
[d/l]
[select]