mailund/cli

Command line parsing for go

cli's Issues

Document argument tags

I'm not sure where in the source I can add documentation for the tags, but it has to go somewhere.

Document callbacks

The README doesn't describe that a struct can have a callback field.

Choices from maps

Ideally, we should get the options in a choice from the keys of a map, but then I need to handle all kinds of maps or use reflection, which gives the user an ugly interface. I'll wait for generics before I do that. A generic map[string]T will make it easy, and generics shouldn't be far away now...

Passing options from parents to subcommands

This is doable in various ways, but I don't know if I can do it without making too strong a coupling between commands, that I might not want to have.

Posix/gnu flags

Go's flags start with a single dash but almost everyone else use double dashes for flags with more than one character in the name. Check if there is a replacement package I can use instead of flag.

Better 'value' text for more of the types

Flag help shows "--flag value", but the types can change "value", and since I autogenerate them, I should do that. Same for the files. Choices already do this.

Choice-parameters (and maybe flags)

When a parameter must be one of a set of options, the user shouldn't have to use a string parameter and then check the result him/herself. It is simple to create a set of options, so that should be part of params.ParamSet. I can't insert the same in flag module, but with a callback function it should be easy to add the functionality.


Add one or two complete programs to the README documentation

Show how the commands are used in a complete program, and show the usage information they print.

Add file types to specs

If an argument is a reader or writer, the parser can open the files automatically. For flags, the default can easily be set to stdin/out/err

Simplify and refactor paramset

I don't need the non-Var functions with the new commands, so I can cut the interface in half.

With the callback interface, I really only need two functions, one for installing a positional argument and one for a variadic. They should then call a callback.

The different types of variables leads to some duplicated code, but maybe I can generate that code automatically.

Value interface for fields.

Flags have a Value interface that can work as a callback interface. If I can check if the field implements that, then I can do the same. It might be a simpler interface for extending the module.

Don't allow variadic arguments for commands with subcommands

The subcommans always gobble up the rest of a command-line, so we can't have variadic parameters as well...