NAME
    Chemistry::MolecularMass - Perl extension for calculating molecular mass of a chemical compound given its chemical formula.

VERSION
    0.1

AUTHOR AND COPYRIGHT
    Copyright (C) 2000, Maksim A. Khrapov maksim@recursivemind.com http://www.recursivemind.com

    This program is distributed under Perl Artistic Lisence. No warranty. Use at your own risk.

SYNOPSIS
       use Chemistry::MolecularMass;
       my $mm = new Chemistry::MolecularMass;
       my $mass = $mm->calc_mass("C2H5OH");
       print $mass if defined($mass);

       my %default_macros = $mm->all_macros;
       $mm->add_macros("Ts" => "CH3C6H4SO2", "Bs" => "BrC6H4SO2");
       $mass = $mm->calc_mass("TsOEt");
       $mass = $mm->calc_mass("{[(CH3)3Si]2N}2CHCH<CH2Br>2");

       ### if you are an organic chemist, you might want to do this:
       $mm->add_macros("Pr" => "C3H7", "Ac" => "CH3COO");

       my %elements = $mm->all_elements;
       $mm->replace_elements("Na" => 24.00, "Cl" => 37.00);
       $mass = $mm->calc_mass("NaCl");

DESCRIPTION
       Chemistry::MolecularMass is an Object Oriented Perl module for calculating
       molcular mass of chemical compounds implemented with Perl and C.
       Molecular masses of elements stored in the module follow recommendations
       of IUPAC (1995). The module includes elements from H(1) through
       Uuu(113) and isotopes of hydrogen: deuterium and tritium. The module
       also allows a programmer to change the default masses of elements
       for work with isotopes. It also includes some of the more common
       chemical abbreviations as macros and allows to add new macros and
       change the values of old macros. A hash of all macros and a hash
       of all elements can be returned.

       Arbitrary element names can be added, they are expected, however, to
       start with an upper case letter followed by zero or more lower case
       letters. Macros can be any string of characters. Macros are substituted
       only once, so a macro should not evaluate to another macro. Legal
       characters in a formula are: A-Za-z0-9<>{}[]()
       Spaces are not allowed. Parentheses can be nested arbitrarily deep.

       Each MolecularMass object has its own hashes of macros and element 
       masses, so modifications made to one MolecularMass object do NOT
       affect another. The whole thing was programmed with reentrancy
       in mind, so it should be thread safe as well.