Valid Number
Author: Steve Mynott
You want to check if a string is a valid number.
Most of the time you will not need to do this. Rather then testing for a scalar's numerical nature you can ensure that the variable contains a number by setting its type. Assigning a number to that variable will cause it to be coerced into an integer or a number.
Ensure that a variable is used to store a real number.
my Num $number;
Ensure that a variable is used to store an integer.
my Int $integer;
Sometimes you need to validate a string from some source corresponds to a real or an integer. In this situation compare it against the rule for integers or reals.
Source code: 02-01valid-number.p6
#!/usr/bin/env perl6 use v6; type(12); type(14.12); sub type ( $string) { print $string ~ ' is a '; given $string { when Int { say "Integer"; } when Rat { say "Rational"; } } }