Tags: patch

ERC could really benefit from a more efficient, convenient, and flexible
means of modifying how words (mainly nicks) are buttonized in messages.

The approach being proposed here involves replacing the preferred type
of the third, "form" field in `erc-button-alist' entries. It's currently
an arbitrary "guard"-like sexp, which I'd like to deprecate in favor of
a function capable of rewriting the button itself. The deprecated form
would still be usable but would trigger a warning, going forward. A
special accommodation would be made for the constant t as well as for
special variables, whose values would be treated as booleans. This would
cover all existing default entries as currently used in client code.

The idea is for this new "rewriter" function to expect the bounds of the
button under consideration as input and to return something similar, or
nil, to indicate that the candidate ought to be skipped (as in not
buttonized). A separate variant with a different signature will be
required for nicknames since they're already treated specially. It'll be
passed additional arguments, such as `erc-server-user' and
`erc-channel-user' objects and a casemapped nickname, all of which are
already present in the caller's environment. Additionally, the values of
user options containing faces to be applied, such as
`erc-button-nickname-face' and `erc-button-face' will be free for the
changing, with all damage limited to the current button alone.

As an example of a possible application for this, I have included a
helper for displaying messages involving `substitute-command-keys'.
Other applications include button colorization and alternate display
text. Practical implementations of both are available on request.

The second patch contains the actual changes proposed above. The first
is only somewhat related but trivial enough to smuggle in with this set
(IMO). The last one I threw in on a whim. It adds additional flexibility
for third parties but will most likely be dropped or held back because
there's no immediate use for it in ERC's client code.

Thanks.


In GNU Emacs 30.0.50 (build 2, x86_64-pc-linux-gnu, GTK+ Version
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