NAME
Silly::StringMaths - Perl extension for doing maths with strings
SYNOPSIS
use Silly::StringMaths qw(add subtract multiply divide exponentiate);
# Add two positive numbers - returns ABFOOR
print add("FOO", "BAR");
# Add a generally positive number and a negative number
# - returns ot
print add("FNoRD", "yncft");
# Subtract several numbers from a rather large one
# - returns accdeiiiiloopssu
print subtract("Supercalifragilisticepsialidocious",
"stupid", "made", "up", "word");
# Multiply two negative numbers - returns AAACCCCCCEEELLLNNN
print multiply("cancel", "out");
# Divide two numbers - returns AAA
print divide("EuropeanCommission", "France");
# Confirm Pythagorus' theorum - returns nothing
print subtract(exponentiate("FETLA", "PI"),
exponentiate("TLA", "PI"),
exponentiate("ETLA", "PI"));DESCRIPTION
Silly::StringMaths provides support for basic integer mathematics, using strings rather than numbers. Upper-case letters are positive, lower-case letters are negative, so ABCDEF would be 6 (but WOMBAT would also be 6), whereas positive would actually be -8. Mixed-case is also possible, so Compaq is actually -5. Most methods return a canonicalised version of the string - e.g. ampq rather than Compaq (mixed case removed, the result sorted alphabetically).
The behaviour of other characters is as yet undefined, but be warned that non-alphabetical characters may be reserved for floating point or imaginary numbers.
Actual numbers (i.e. the characters 0 to 9) will never be used by this module.
BASIC METHODS
add
Takes an array of strings, returns the sum.
subtract
Takes a string, subtracts all other supplied strings from it and returns the result.
multiply
Takes a string and multiplies it by all the other strings, returning the resulting product.
divide
Takes a string, and divides it by all the other strings, returning the result. Results are rounded down.
exponentiate
Takes a number, raises it to the appropriate power, as specified by the other arguments. Returns the result. (Note that some textual information is lost here - the result will be either As or as).
USEFUL TOOLBOX METHODS
normalise
Takes a string with, potentially, a mix of upper-case and lower-case letters, and returns a sorted string that is unmistakeably either positive or negative.
sign
Returns the sign of a number as either 1, 0 or -1 (as a string, obviously).
negative
Returns whether the supplied string is negative or not
invert
Takes a reference to a number, inverts it.
AUTHOR
Sam Kington, sam@illuminated.co.uk
SEE ALSO
perl(1).