Re: Re: creating a particular hash

[Henri Icarus]

Don't you love how lisp made it's way into perl?

Now if only there were also the beauties of cond...

[princepawn]

have you seen Switch?

Also, because I am converting a lot of lisp and scheme code, I dont really like cond very much.

In Perl, I can be much more concise:

return undef if !$bindings ;
return (extend $bindings) if (var_match $pattern) ;
return pat_match(rest $input) if @$input ;

The equivalent cond I do find a bit harder to follow.

[Ovid]

If you have a default value to return, this is where I prefer to chain the "x ? y : z" operator:

return ! $bindings        ? undef                  :
       var_match $pattern ? extend $bindings       :
       @$input            ? pat_match(rest $input) :
                            $default_value;

I know that it looks a little odd at first, but once you get used to the syntax, I find it even easier than case or switch statements.

Cheers,
Ovid

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[Henri Icarus]

Don't you get into trouble with operator precedence when you do this and start using && and such in your conditionals? Or am I just remembering old bugs in my C code :-)