Ado file, syntax for several variable groups

Question

I wish to create an ado file, which has four categories of variables.

The idea is that the user can input something like:

myprog depvar biggroup, ingroup(varlist1) outgroup(varlist2)

In this example depvar and biggroup are single variables, while ingroup is at least two variables and the outgroup is the same but optional.

So far i have attempted the following:

program myprog, rclass
    version 15
    syntax varlist(min=2 max=2), ingroup(min=2) [outgroup]
    local depvar: word 1 of `varlist'
    ...
end

I can pull apart varlist based on word count to create the depvar and biggroup variables as I did for depvar.

However, I am unsure how to create the additional lists for ingroup and outgroup. The issue is that they can both include a varied number of variables and I do not know how to differentiate them with either the syntax or args commands.

Answer 1

You can also use a varlist for each option. Or alternatively you could pass them as strings.

Here's the solution using a varlist:

capture program drop myprog
program define myprog, rclass
    version 14
    syntax varlist(min=2 max=2), ingroup(varlist min=2) [outgroup(varlist min=2)]
    display ""
    display "`varlist'"
    display ""
    display "`ingroup'"
    display ""
    display "`outgroup'"
end

. clear

. generate one = runiform()
. generate two = runiform()
. generate three = runiform()
. generate four = runiform()
. generate five = runiform()
. generate six = runiform()
. generate seven = runiform()

. myprog one two, ingroup(three four) outgroup(five six seven)

one two

three four

five six seven