Ideas for future Syntax enhancements

Here are some ideas for work to be done in this area:

• Extend OptionSetSyntax to support "--" as meaning everything after here is not an option.
• Make OptionSetSyntax smarter in its handling of repeated options. For example completing "cp --recursive " should not offer "--recursive" as a completion.
• Improve "help", including improving the output, incorporating more descriptions from the syntax, in preference to descriptions from the Command class, and supporting multi-lingual descriptions. (In fact, we need to go a lot further ... including supporting full documentation complete with a way to specify markup and cross-references. But that's a different problem really.)
• Extend the Argument APIs so that we can specify (for example) that a FileArgument should match an existing file, an existing directory, a path to an object that does not exist, etc. This potentially applies to all name arguments over dynamic namespaces.
• Extend the Argument APIs to support expansion of patterns against the FS and other namespaces. This needs to be done in a way that allows the user, shell and command to control whether or not expansion occurs. We don't want commands to have to understand that there are patterns at all .... except in cases where the command needs to know (e.g. some flavours of rename command). And we also need to cater for shell languages (e.g. UNIX derived ones) where FS pattern expansion is clearly a shell responsibility.
• Add support for command-specific Syntax classes; e.g. to support complex command syntaxes like UNIX style "expr" and "test" commands.
• Add command syntax support for command-line interactive commands like old-school UNIX ftp and nslookup. (In JNode, we already have a tftp client that runs this way.)
• Implement a compatibility library to allow JNode commands to be executed in the class Java world.