How to specify that an optional argument requires 2 arguments in a zsh competition script?

Question

I am writing a custom competition function for zsh. Currently, I have the following code

_arguments \
...
'(-G --glitchpct)'{-G+,--glitchpct=}'[Controls how often the characters on screen glitch]'

I am currently specifying that -G VALUE or glitchpct=VALUE or --glitchpct VALUE are acceptable(mutually exclusive as they are part of the same group).

What if I need to have 2 argument values instead of one? That is, I expect to have -G VALUE1 VALUE2 or --glitchpct=VALUE1,VALUE2. How could I specify this? Also, how would it be different if there are 3, etc. arguments?

Additionally, would it be possible to display a custom message for each argument? Say VALUE1 should display 'float from 0 to 50', and VALUE2 should display 'float from 100 to 150' on the screen. I assume it is possible to do that through the _message builtin but I am unsure how to make it work. I tried specifying the state like this(this is for only 1 value as I haven't figured out how to use two):

_arguments \
...
'(-G --glitchpct)'{-G+,--glitchpct=}'[Controls how often the characters on screen glitch]:float:->display_float'
...
case "$state" in
        (display_float)
            _message "sample message"
        ;;
    esac

but this didn't see to display anything. The following form didn't work either:

'(-G --glitchpct)'{-G+,--glitchpct=}'[Controls how often the characters on screen glitch]:float:_message "sample message"

Answer 1

I provided the comment above in hopes it would lead you to the example containing an argument array. Here's the example copied directly from the link:

_arguments '-m[music file]:filename:->files' '-f[flags]:flag:->flags'
case "$state" in
    files)
        local -a music_files
        music_files=( Music/**/*.{mp3,wav,flac,ogg} )
        _multi_parts / music_files
        ;;
    flags)
        _values -s , 'flags' a b c d e
        ;;
esac

The above example taken from the Howto shows how to treat the argument passing as an array. Breaking apart the example:

1. The argument -m may also be -ma. Including the a lists all music files removing the need for filename.
2. The flags section while not as fleshed out allows -f to be initialized as -fs with possible values of -fa through -fe

Relating to your code: Consider Something Like the code above in the following format:

_arguments '-G[glitchpercentage]:gpercent:->percents' '-f[flags]:flag:->flags'
case "$state" in
    percents)
        local -a percents
        glitchpercentage=\\do something to set to 100%
        _message "Some message for all option"
        local -h percents
        glitchpercentage=//do something to set to 50%
        _message "Some message for half option"
        ;;
    flags)
         // Add these to control the program, i.e. use these options
         // if they dont control something in the percents array.
        _values -s , 'flags' a b c d e
        ;;
esac

The above hasn't been tested so please treat it as psuedo-code. Using an array as above is what I think you're looking for.