automatic code loading system (acls)

The Automatic Code Loading System (ACLS) is a Ruby library intended to help speed up and simplify development time by allowing developers to define pathes and patterns of files that should be autoloaded when their application runs.

Rails does something like this. In a Rails application you would change your autoloading paths as such:

config.autoload_paths += ['lib', 'other/lib', 'etc'].map { |folder| "#{config.root}/#{folder}" }

Rails will then look for all Ruby files in those directory trees and load them for immediate use into your application. However, Rails does this in a very complex manner by taking over the flow for when a constant isn't found. ACLS does not do that. I have chosen a more straight-forward solution, which simply generates an autoload statement for all Ruby files in a set of paths.

As an example, assume the following directory structure:

- lib
| - one.rb
| - two.rb
| - sub
| | - three.rb
- other
| - four.rb

Pass in the desired directory paths into the ACLS module:

ACLS::Loader.auto(['lib', 'other'])

That one line with ACLS is equivalent to hand-writing the following Ruby code:

autoload :One, 'lib/one.rb'
autoload :Two, 'lib/two.rb'
module Sub
  autoload :Three, 'lib/sub/three.rb'
end
autoload :Four, 'other/four.rb'

The simplest way is to use:

ACLS::Loader.auto(['path', 'to/one/or/more', 'directories'])

ACLS will automatically generate new module constants if it needs to. This method of autoloading, however, makes assumptions about the directory structure. The top-level directory is assumed to carry no namespace but every sub-directory under that does imply a namespace. To customize bits of the behavior, an options hash can be passed in as a second argument:

ACLS::Loader.auto('lib', {root_ns: true})

Options available:

• root_ns: When true, this will use the top-level directory name as the root namespace for all files and folders in the tree. When a string is supplied, this will use the string as the name of the root namespace. For all other values, the root directory is not a namespace and everything falls under the Object namespace.
• exclude: Must be a collection of strings and/or regexps. For each string in the collection, files are excluded from autoloading if they match the name exactly. For each regexp in the collection, files are excluded from autoloading if the path results in a successful match on the regexp.
• immediate: Must be a collection of strings and/or regexps. Follows the same conditional pattern as exclude, but on a match this will immediate load the file via load instead of deferring it using autoload.

When talking about matching, there are two attributes: names and paths.

A name is the base file or directory name, without the Ruby file extension (if it has one). e.g. lib/foobar.rb would have a name of foobar.

A path is the full path to a file or directory. e.g. lib/foobar.rb, lib/sub/directory.

Strings tend to match against names, because names are shorter and strings are meant for simple matching. Regexps tend to match against paths because a path contains more information and regexps allow you to have more detailed control over the matching conditions.

• Generate autoload statements based on a set of directory paths.
• Generate static autoload file to be used for quicker application startup in production deployments.

• Implement root_ns.
• Implement exclude.
• Implement immediate.