File Coverage

blib/lib/Math/SymbolicX/Calculator/Command.pm

Criterion	Covered	Total	%
statement	19	25	76.0
branch	1	4	25.0
condition	0	3	0.0
subroutine	6	7	85.7
pod	1	1	100.0
total	27	40	67.5

package Math::SymbolicX::Calculator::Command;

use 5.006;
use strict;
use warnings;
use Carp qw/croak/;

our $VERSION = '0.02';

use vars qw/@CMDS/;

# load the command classes.
BEGIN {
    @CMDS = qw(
        Assignment
        Transformation
        DerivativeApplication
        Insertion
    );
    foreach (@CMDS) {
        eval "require Math::SymbolicX::Calculator::Command::$_;";
        die "Could not load Math::SymbolicX::Calculator::Command::$_. Error: $@"
          if $@;
    }
}

=encoding utf8

=head1 NAME

Math::SymbolicX::Calculator::Command - Base class for Calculator commands

=head1 SYNOPSIS

  use Math::SymbolicX::Calculator;
  my $calc = Math::SymbolicX::Calculator->new();

  # setup formula to be a Math::Symbolic tree or a transformation...

  my $assignment = $calc->new_command(
    type => 'Assignment', symbol => 'foo', object => $formula,
  );

  $calc->execute($assignment);

=head1 DESCRIPTION

This class is a base class for commands to the a
L object. Various commands are implemented as
subclasses. See below for a list of core Commands and their usage.

=head1 AVAILABLE COMMANDS

=head2 Assignment

L is an assignment
of a formula or transformation to a symbol table slot.

Parameters to the constructor:

  symbol => the symbol name to assign to
  object => Math::Symbolic tree or
            Math::Symbolic::Custom::Transformation to assign
            to the symbol

Execution of this command returns the following list:
C<$sym, '==', $func> where C<$sym> is the name of the modified symbol
and C<$func> is its new value.

=head2 Transformation

L is a transformation
application to a formula stored in a symbol table slot.

Parameters to the constructor:

  symbol  => the name of the symbol to modify
  trafo   => Math::Symbolic::Custom::Transformation object to apply
  shallow => boolean: Set this to true to apply shallowly or to
             false to apply recursively (default)

Execution of this command returns the following list:
C<$sym, '==', $func> where C<$sym> is the name of the modified symbol
and C<$func> is its new value.

=head2 Insertion

L is a replacement
of all variables in a formula (in a symbol table slot) by what's found
in the symbol table under the corresponding variable names.

Parameters to the constructor:

  symbol => the name of the symbol to modify
  optional:
  what   => the name of the variable to replace with its symbol
            table value or '*' for everything
            Defaults to everything.

Execution of this command returns the following list:
C<$sym, '==', $func> where C<$sym> is the name of the modified symbol
and C<$func> is its new value.

=head2 DerivativeApplication

L
is the application of all derivatives in a function in a
symbol table slot.

Parameters to the constructor:

  symbol => the name of the symbol to modify
  optional:
  level  => the number of nested derivatives to apply.
            Defaults to all/any (undef).

Execution of this command returns the following list:
C<$sym, '==', $func> where C<$sym> is the name of the modified symbol
and C<$func> is its new value.

=head1 METHODS

=cut

=head2 new

Returns a new Command object. Takes named parameters. The only
universally mandatory parameter is the C of the command to
create. All paramaters are passed thorugh to the constructed
of the implementing subclass. That means if C is C,
then C will call
Cnew()>
with its arguments.

=cut


sub new {
    my $proto = shift;
    my $class = ref($proto)||$proto;

    my %args = @_;

    croak("Need 'type' argument to " . __PACKAGE__ . "->new()")
      if not defined $args{type};
    $class .= "::" . $args{type};
    return $class->new(@_);
}


1;
__END__