Re: st: Recursively build local macro with "" around each addition

[Nick Cox <njcoxstata@gmail.com>]

The problem is that Stata has a default meaning that "  " are string
delimiters. They are not part of a string by default.

It follows that if you wish Stata to treat " " as literal characters
to be included within a string, you need other string delimiters and
Stata provides `" "' for this purpose.

You know this, but the one quoted example you give that doesn't work
fails because it doesn't satisfy this rule. That is, although the last
"' could be a string delimiter its partner `" can't be because it
occurs _within_ the string.

At least, that's my interpretation; and in any case the code below
seems to do what you want.

* begin code
local output
local arg1 ten
local arg2 one two
local state lo hi

foreach a1 of local arg1 {
   foreach a2 of local arg2 {
       foreach s1 of local state {
           foreach s2 of local state {
               local output `" `output' "`a1' `s1', `a2' `s2'" "'
           }
       }
   }
}
display `"`output'"'
* end code

Nick

On Mon, Feb 13, 2012 at 8:01 PM, Richard Herron
<richard.c.herron@gmail.com> wrote:
> I would like to recursively build a local macro that wraps each
> addition in double quotes.
>
> For example, I loop slowly over "lo" and "hi" states of words in the
> first local macro, and quickly over "lo" and "hi" states of the second
> local macro. The following code generates a local macro that properly
> orders the states, but doesn't wrap each addition in double quotes.
>
> * begin code
> local output
> local arg1 ten
> local arg2 one two
> local state lo hi
>
> foreach a1 of local arg1 {
>    foreach a2 of local arg2 {
>        foreach s1 of local state {
>            foreach s2 of local state {
>                local output "`output'" "`a1' `s1', `a2' `s2' "
>            }
>        }
>    }
> }
> display "`output'"
> * end code
>
> The output is in the correct order, but doesn't have double quotes
> around each addition.
>
> . ten lo, one lo ten lo, one hi ten hi, one lo ten hi, one hi ten lo, two
>> lo ten lo, two hi ten hi, two lo ten hi, two hi
>
> Instead, I would like the following.
>
> . "ten lo, one lo" "ten lo, one hi" "ten hi, one lo" "ten hi, one hi"
> "ten lo, two
>> lo" "ten lo, two hi" "ten hi, two lo" "ten hi, two hi"
>
> I will use this string as an argument for the -mtitles()- option in
> -esttab- in SSC's -estout- package (-ssc install estout-).
>
> I tried combinations of `' and "" that seemed logical, but got either
> -invalid syntax- or only the last addition without double quotes and
> -lo not found-. (E.g., I thought that -local output "`output'" `""`a1'
> `s1', `a2' `s2' ""'- would provide double quotes, but this also yields
> -invalid syntax-).
>

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