/ 
Graphics-Grid-0.0000_03
River stage zero No dependents
/ Graphics::Grid::UnitArithmetic

NAME

Graphics::Grid::UnitArithmetic - Expression created from Graphics::Grid::Unit objects

VERSION

version 0.0000_03

SYNOPSIS

use Graphics::Grid::UnitArithmetic;
use Graphics::Grid::Unit;

my $ua1 = Graphics::Grid::UnitArithmetic->new(
    node     => '+',
    children => [
        Graphics::Grid::Unit->new( [ 1, 2, 3 ], "cm" ),
        Graphics::Grid::Unit->new(0.5),
    ],
);
my $ua2 = Graphics::Grid::UnitArithmetic->new(
    Graphics::Grid::Unit->new(0.1, "npc")
);
my $ua3 = $ua1 - $ua2;
my $ua4 = $ua1 * 2;

# or use the function interface
use Graphics::Grid::Functions qw(:all);
my $ua = unit(@params) * 2;

DESCRIPTION

You would mostly never directly use this class. See Graphics::Grid::Unit for unit arithmetic on unit objects.

This class Graphics::Grid::UnitArithmetic represents arithmetic on Graphics::Grid::Unit objects. It provides a way to create a unit-like value that combines both relative and absolute values.

Supported operators are +, -, and *. A plus or minus operation requires both its binary operands are consumers of Graphics::Grid::UnitLike. The multiply operation requires one of its operands is consumer of Graphics::Grid::UnitLike, the other a number or array ref of numbers.

ATTRIBUTES

node

It can be one of the followings,

  • A number or an array ref of numbers. If a single number is given it will be coerced to an array ref that contains the number. This is used for operands of multiplications.

  • One of "+", "-", "*". In this case the children attr should contain the operands.

  • A Graphics::Grid::Unit object. This is used for operands of plus and minus.

children

When the object represents an arithmetic operation, this children attribute has the operands.

METHODS

at($idx)

This method returns an object of the same Graphics::Grid::UnitArithmetic class. The returned object represents the data at given index, and has at only one value at each node.

# $ua1 has 3 elems: 1cm+0.5npc, 2cm+0.5npc, 3cm+0.5npc
my $ua1 = Graphics::Grid::UnitArithmetic->new(
    node     => '+',
    children => [
        Graphics::Grid::Unit->new( [ 1, 2, 3 ], "cm" ),
        Graphics::Grid::Unit->new(0.5),
    ],
);

# $ua2 has only 2cm+0.5npc
my $ua2 = $u1->at(1);

$idx is applied like wrap-indexing. So below is same as above.

my $ua3 = $ua1->at(4);

elems

Return the number of effective elements in the object.

is_unit

Checks if the object is a Graphics::Grid::Unit.

is_number

Checks if the object is an array ref of numbers.

is_arithmetic

Check is the object is an arithmetic operation. It is equivalent to !($obj-≥is_unit() or $obj-≥is_number()).

stringify

Stringify the object.

SEE ALSO

Graphics::Grid

Graphics::Grid::UnitLike

Graphics::Grid::Unit

Forest::Tree

AUTHOR

Stephan Loyd <sloyd@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2018 by Stephan Loyd.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.