Wheel Factory

This is just a placeholder repo for future library.

Wheel factory is a thing for those who likes reinventing wheels - creating CLI applications from scratch. It all started with absence of good CLI frameworks in Java, so i thought it would be cool to implement one-size-fits-all C library.

Features

The forthcoming project is implied to have those features:

Namespaces and commands

All commands reside in namespaces, including root empty namespace. Command builder dependency tree visualize should decode following tree:

<root>: namespace
  dependency: namespace
    tree: namespace
      visualize: command

Commands

Commands have handlers attached to them, which receive two parameters:

• Parsed configuration
• void*, which is implied to contain user-provided context (if any).

Namespace options

Namespace may declare it's own options. It is quite common to have option for all commands at once, e.g. -p for profile:

application -p staging serve

At the same time, library should allow end user to specify same-named options for other namespaces and commands. Following command:

application -p staging serve -p 8080

Should produce following tree:

<root>:
  options:
    -p: staging
  

At the same time, if serve command doesn't have -p configured, it should be propagated to upper level, then, if nothing has been found on upper level, to lower level, i.e. library should recognize both examples:

# serve doesn't have -p configured
application serve -p staging

# root namespace doesn't have -p configured
application -p 8080 serve

Namespace arguments

Namespace may declare arguments as well. Following command:

steward release 0.1.0 push

should recognize 0.1.0 as argument.

At current moment it seems reasonable that namespace must have a fixed number of arguments.

Arguments & Options

Argument arity

Library should support argument arity, except for ambiguous cases. E.g. it should be safe to declare executable command {arg1 x 2} {arg2 x 2}, but executable command

Option decoding

End user should be able to enable or disable following options:

• Decoding -tulpn in same way as -t -u -l -p -n
• Decoding -t4 and -tttt as -t 4
• Combination: decoding -at4 as -a -t 4
• Decoding multi-symbol shortcut options: -at4 can be -at 4 if such option exists

Global overrides

End user should be able to supply global overrides that take precedence over command handlers

Custom validations

It should be possible for end user to provide custom validators for options and arguments.

Predefined functionality

Help command

Good old help command that can be used with -h or --help flag or with help <command>.