erc-with-buffer
erc-with-buffer is a Lisp macro in `erc.el
'.
(erc-with-buffer (TARGET [PROCESS]) BODY...)
Execute BODY in the buffer associated with SPEC.
SPEC should have the form
(TARGET [PROCESS])
If TARGET is a buffer, use it. Otherwise, use the buffer
matching TARGET in the process specified by PROCESS.
If PROCESS is nil, use the current `erc-server-process'.
See `erc-get-buffer' for details.
See also `with-current-buffer'.