Re: Regexp to match 't' in a nested list?

[Jambunathan K]

\_<t\_>

See (info "(elisp) Regexp Backslash")

Thorsten Jolitz <tjolitz@gmail.com> writes:

> Hi List, 
>
> for making Emacs Lisp talk to PicoLisp, I have to upcase t and nil (T
> and NIL in PicoLisp) in nested lists that contain all kinds of strings
> and keywords in possibly many languages. Using the more difficult 't'
> case as example, so far I came up with this regexp that doesn't seem to
> give false positives: 
>
> ,------------------------------------------
> | "\\( t \\|(t \\| t)\\|(t)\\|^t \\| t$\\)"
> `------------------------------------------
>
> (same thing for nil, just replace t with nil)
>
> But the regexp misses at least one case: a string like 
>
> ,----------------
> | " t t nil nil "
> `----------------
>
> will be converted to 
>
> ,----------------
> | " T t NIL nil "
> `----------------
>
> I cannot find a solution for this case that does not immediately results
> in false positives when applied to a string like 
>
> ,------------------------------------------------
> | " t t nil nil total albanil nilonga tat mitat "
> `------------------------------------------------
>
> Any tips/hints would be appreciated.