{smcl}
{bf:Mata course:  Ado-file programming}
{hline}

{title:Basic outline}

	{hline}
	{cmd}program ...
		syntax varlist [if] [in] ...
		marksample touse
		....
		mata:  myfunction("`varlist'", "`touse'")
		...
	end

	mata:
	void myfunction(string scalar varnames, string scalar touse)
	{c -(}
		real matrix	x
		...

		...
		st_view(x, ., tokens(varnames), touse)
		...
	{c )-}
	end{txt}
	{hline}

{p 4 4 2}
This was the outline we used in {bf:{view varsum.ado}}.


{title:Improved outline}

	{hline}
	{cmd}program ...
		syntax varlist [if] [in] ...
		marksample touse
		....
		mata:  myfunction("varlist", "`touse'")
		...
	end

	mata:
	void myfunction(string scalar varmac, string scalar touse)
	{c -(}
		real matrix	x
		string scalar	varnames
		...

		...
		varnames = st_global(varmac)
		st_view(x, ., tokens(varnames), touse)
		...
	{c )-}
	end{txt}
	{hline}

{p 4 4 2}
We can shorten {cmd:myfunction}:

	{cmd}void myfunction(string scalar varmac, string scalar touse)
	{c -(}
		real matrix	x
		...

		...
		st_view(x, ., tokens(st_global(varmac)), touse)
		...
	{c )-}{txt}

{p 4 4 2}
That is, 

{p 8 8 2}
If a macro is long

{p 12 12 2}
do not pass {cmd:"`macro'"} 

{p 12 12 2}
pass {cmd:"macro"}

{p 8 8 2}
and then take {cmd:st_global()} of it.


{title:Another example}

{p 4 4 2}
See 
{bf:{view hsearch.ado}}.




{hline}
{bf:{view talk.smcl:Top}}