Re: eval-when-compile vs defconst

["Stuart D. Herring" <herring@lanl.gov>]

>     (defvar ada-block-start-re
>       (eval-when-compile
> 	(concat "\\<\\(" (regexp-opt '("begin" "declare" "else"
> 				       "exception" "generic" "loop" "or"
> 				       "private" "select" ))
> 		"\\|\\(\\(limited\\|abstract\\|tagged\\)[ \t\n]+\\)*record\\)\\>"))
>       "Regexp for keywords starting Ada blocks.")
>
> It would not be worth any extra complexity just to avoid one call to
> concat when the file is loaded.  So even if eval-when-compile were not
> a no-op here, I'd say take it out.

Surely it's there to avoid calling (and loading) `regexp-opt' at load
time, and the concat is merely along for the ride?  Unless the optimizer
already evaluates calls to `regexp-opt' on quoted lists, it seems useful
to me.

Davis

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