Simple wrapper for set trace

[Michael Harris differentiated]

Edit: After some testing, it appears to be a scope issue; set trace on applies only to the context of the wrapper program. So, is there any way to make the effect of set trace apply globally?

I am attempting to write wrapper programs that allow me to type ston and stoff instead of set trace on and set trace off. I am using Stata 16 for unix. I have created the following files:
ston.ado:

program ston
    version 16
    set trace on
end

stoff.ado:

program stoff
    version 16
    set trace off
end

However, these do not have the desired effect. Starting with trace set to off, I can issue the command ston as many times as I like and no output is produced. If I instead set trace on[/CODE], then I can call either ston or stoff as many times as I like and I get the output:

------------------------------------------------------------------------------------------------------------ begin ston ---
- version 16
- set trace on
-------------------------------------------------------------------------------------------------------------- end ston ---

or

----------------------------------------------------------------------------------------------------------- begin stoff ---
- version 16
- set trace off
------------------------------------------------------------------------------------------------------------- end stoff ---

every time. [Edit: So the programs are acknowledged and executed but with no apparent effect, at least with respect to the command window where I am typing interactively. Could it be a scope issue? That would surprise me.]
I have searched for answers about simple wrappers and wrappers for set trace to no avail. Why doesn't this work as expected? Is there a better solution?

[daniel klein]

See sto and tr both from SSC.

Best
Daniel

[Nick Cox]

Daniel Klein documents my sto package on SSC with identical intent. It was broken utterly by a change of the form you fear in a new release of Stata, perhaps two or three versions ago.

[Michael Harris differentiated]

Thanks for those references. The behavior I want is closest to sto, and I was able to get something close by putting the commands in a local macro like

loc ston set trace on
loc stoff set trace off

and then typing `ston' and `stoff' as needed.
A final request: I'd like to be able to type `sto' instead as a toggle. Can I access the state (on or off) of trace somehow, for making the local macro store an if command?

[Michael Harris differentiated]

I see how to do it from Nick's sto code from SSC. The command local onoff : set trace is wonderful. Where is that kind of command documented? I do not see anything about : set trace in the documentation for macro in the Programming Reference Manual.

[Michael Harris differentiated]

My solution is

loc sto set trace \`=cond("\`: set trace'" == "on", "off", "on")'

which is messy but works. It delays substitution so the status of trace can be determined interactively.
The command to invoke the toggle is `sto'.
I put the line in a separate file and then used include, but it could also be pasted in a do-file directly.

[daniel klein]

Nick wrote that quite a while ago. My guess is that this was once documented. In modern Stata, type

display c(trace)

and

help creturn

for more information.

Best
Daniel

[daniel klein]

Why do you want this in the first place?

If you are looking for a quick way to set trace on and off, try

global F4 set trace on;
global F5 set trace off;

You can then set trace on and off by pressing the F4 and F5 buttons, respectively.

Best
Daniel

[Michael Harris differentiated]

Thank you, Daniel. I had forgotten that trace information is stored in the c-class. I also was unaware that I could assign macros to the keyboard. I created a toggle key by combining your #8 and my #6.