syntax [varname] and syntax [varlist] with no argument give "too many variables specified error'

[Joseph Coveney]

What am I doing wrong here? It's undoubtedly something too obvious for me to see.

.ÿversionÿ14.2

.ÿ
.ÿclearÿ*

.ÿsetÿmoreÿoff

.ÿ
.ÿprogramÿdefineÿshowm
ÿÿ1.ÿÿÿÿÿÿÿÿÿversionÿ14.2
ÿÿ2.ÿÿÿÿÿÿÿÿÿsyntaxÿ[varname]
ÿÿ3.ÿ
.ÿend

.ÿ
.ÿsysuseÿauto
(1978ÿAutomobileÿData)

.ÿ
.ÿshowmÿforeign

.ÿ
.ÿshowm
tooÿmanyÿvariablesÿspecified
r(103);

endÿofÿdo-file

r(103);

.

The help file for syntax indicates that optional variable name and variable list are acceptable, but it seems not to work unless a variable is supplied.

[Nick Cox]

Joseph: I can't copy and paste your code without strange fill characters being imported: please use CODE delimiters.

How about this? Optional varname means that all variables are used by default, but that clashes with the prescription of a single variable name. Otherwise put, there can't be an obvious default variable name unless the dataset consists of a single variable. This works:

clear

program showm
version 14.2
syntax [varname]
end

sysuse auto, clear
keep foreign 
showm

[Joseph Coveney]

Optional varname means that all variables are used by default

That's it; thanks Nick. I thought that if no variable is specified, then varlist would be empty.

[Jesse Wursten]

The code below works for me.

    syntax [varlist(default=none)]

From help syntax, "default= specifies how the varlist is to be filled in when the varlist is optional and the user does not specify it. The default is to fill it in with all the variables. If default=none is specified, it is left empty."
I have to admit, it's not my first intuition either.

[Nick Cox]

Jesse: Joseph's title implied that such syntax is problematic, but he did not follow that up in his post. I agree with you: it's not problematic.

[Joseph Coveney]

From help syntax, "default= specifies how the varlist is to be filled in when the varlist is optional and the user does not specify it. The default is to fill it in with all the variables. If default=none is specified, it is left empty."
I have to admit, it's not my first intuition either.

I went back to the help file and saw that after reading Nick's reply, but I didn't get that far in the help file before posting—my apologies to the list.

Yeah, it would seem more consistent with, say,

local varlist

to have had the default default as an empty macro, and allow the user to specify something like

syntax [varlist(default=_all)]

And especially with

syntax [varname]

it is difficult to imagine that the typical case would be for the user to want all variables in the dataset as the default.