---
name: "Template::Namespace::Constants"
section: "3pm"
platform: "linux"
package: "perl-template-toolkit"
version: "3.106-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/Template::Namespace::Constants"
---

# Template::Namespace::Constants(3pm)

Compile time constant folding

## NAME

Template::Namespace::Constants - Compile time constant folding

## SYNOPSIS

```
    # easy way to define constants
    use Template;
    my $tt = Template->new({
        CONSTANTS => {
            pi => 3.14,
            e  => 2.718,
        },
    });
    # nitty-gritty, hands-dirty way
    use Template::Namespace::Constants;
    my $tt = Template->new({
        NAMESPACE => {
            constants => Template::Namespace::Constants->new({
                pi => 3.14,
                e  => 2.718,
            },
        },
    });
```

## DESCRIPTION

The `"Template::Namespace::Constants"` module implements a namespace handler which is plugged into the `"Template::Directive"` compiler module.  This then performs compile time constant folding of variables in a particular namespace.

## METHODS

### new(\\%constants)

The **new()** constructor method creates and returns a reference to a new Template::Namespace::Constants object.  This creates an internal stash to store the constant variable definitions passed as arguments.

```
    my $handler = Template::Namespace::Constants->new({
        pi => 3.14,
        e  => 2.718,
    });
```

### ident(\\@ident)

Method called to resolve a variable identifier into a compiled form.  In this case, the method fetches the corresponding constant value from its internal stash and returns it.

## AUTHOR

Andy Wardley \<abw@wardley.org\> \<http://wardley.org/\>

## COPYRIGHT

Copyright (C) 1996-2022 Andy Wardley.  All Rights Reserved.

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

## SEE ALSO

Template::Directive