Daniel D Jones schreef:
> Given something like the following:
>
> my @variables = [3, 7, 13, 4, 12];
> my @tests = ("2*a+b==c", "c-d+a==e");
>
> I need to be able to evaluate the mathematical truth of the tests
#!/usr/bin/perl
# beware: this approach is wrong
use warnings;
use strict;
my $rv = qr~[-+]?(?:[0-9]+|[a-z]+)~ ; # value
my $ro = qr~(?:[-+*/^]|\*\*)~ ; # operator
my $re = qr~\A $rv(?:$ro$rv)* == $rv \z~x ;
my @v = <DATA> =~ /(\d+)/g ;
print join(', ', @v), "\n" ;
while ( <DATA> )
{
chomp ;
tr/A-Z/a-z/ ;
print "$_\t" ;
unless (/$re/) { print "ERROR\n" ; next }
s/([a-z])/($v[ord($1) - ord('a')])/g ;
print "$_\t", eval() ? 'T' : 'F', "\n" ;
}
__DATA__
3, 7, 13, 4, 12
2*a+b==c
c-d+a==e
c-d+a==a
c-d+a==ee
c-d++a==e
-D+c+a==E
2**a==8
2^a==8
--
Affijn, Ruud
"Gewoon is een tijger."
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
<http://learn.perl.org/> <http://learn.perl.org/first-response>
