Raku Config files

Using Raku code to write configuration files.

Author Richard Hainsworth, aka finanalyst

Table of Contents

LicensePurposeInstallation and useSubs Only one sub is exportedget-configTesting

LICENSE

Artist 2

Purpose

Lots of modules need configuration files. Many Raku modules use JSON, or YAML. But neither YAML nor JSON is not Raku, and a configuration file has to be brought in and assigned to a data structure, typically a HASH.

But writing JSON or YAML means memorising the syntax of that language, then mapping it to Raku.

So, why not simply write the file in Raku and use EVALFILE to assign it to a Hash?

This module uses that idea, but allows for the configuration module to be anywhere.

When reading in a configuration file, any Raku code is possible, so configuration files can look at Environment variables, or slurp in local files.

When writing a configuration file, there are many caveats relating to what can be serialised, but for static data, not closures, writing a config file is easy.

Installation and use

Simply

zef install RakuConfig

then

use RakuConfig;
my %config = get-config;
# assumes that 'config.raku' exists in the current directory.
my %big-config = get-config( 'config-files' );
# assumes multiple files of the for config-files/*.raku
# files are evaluated in lexical order
# detects whether keys in one file overwrite a previously set key
# throws an Exception if an overwrite is attempted.

Subs Only one sub is exported

get-config

#| :path is an existing file, or a current directory,
#| if a directory, it should contain .raku files
#| :required are the keys needed in a config after all .raku files are evaluated
#| If :required is not given, or empty, no keys will be tested for existence
#| With no parameters, the file 'config.raku' in the current directory is assumed
#| Previous value of config is not used when :no-cache(True)
multi sub get-config(:$path = 'config.raku', :@required, :no-cache = False)

Testing

To reduce testing and installation hassle, the following have been removed from Test-depends: 'Test::META', 'Test::Deeply::Relaxed', 'File::Directory::Tree'". They will need to be installed to prove the xt/ tests.

Rendered from README at 2022-07-08T22:50:54Z