bug#36237: Support (rx (and (regexp EXPR) (regexp-quote EXPR)))

["Mattias Engdegård" <mattiase@acm.org>]

20 juni 2019 kl. 02.29 skrev Noam Postavsky <npostavs@gmail.com>:
> 
> <0001-Support-rx-and-regexp-EXPR-literal-EXPR-Bug-36237.patch>

Things I didn't notice earlier:

-;; (rx (and line-start (eval something-else))), statically or
-;; (rx-to-string '(and line-start ,something-else)), dynamically.
+;; (rx (seq line-start (regexp something-else)))

You can actually drop the `seq' form entirely, since it's implicit in `rx'.
It was only needed for `rx-to-string' which is now gone.

+`(literal STRING)'
+     matches STRING literally, where STRING is any lisp
+     expression that evaluates to a string.

It's better to name the metavariable EXPR, STRING-EXPR or LISP-EXPR to make it clear that it's an arbitrary lisp expression, especially since STRING is used for a constant string just above.

The same goes for `regexp', since it can now be a lisp expression; this should be mentioned in the describing paragraph, using a similar phrasing. The `literal' item should probably be moved next to `regexp', since they are closely related.

The paragraph on `eval' uses FORM, which is too generic; presumably it should become EXPR too (but not STRING-EXPR, since it can be any rx value).