+(defun notmuch-remove-if-not (predicate list)
+ "Return a copy of LIST with all items not satisfying PREDICATE removed."
+ (let (out)
+ (while list
+ (when (funcall predicate (car list))
+ (push (car list) out))
+ (setq list (cdr list)))
+ (nreverse out)))
+
+; This lets us avoid compiling these replacement functions when emacs
+; is sufficiently new enough to supply them alone. We do the macro
+; treatment rather than just wrapping our defun calls in a when form
+; specifically so that the compiler never sees the code on new emacs,
+; (since the code is triggering warnings that we don't know how to get
+; rid of.
+;
+; A more clever macro here would accept a condition and a list of forms.
+(defmacro compile-on-emacs-prior-to-23 (form)
+ "Conditionally evaluate form only on emacs < emacs-23."
+ (list 'when (< emacs-major-version 23)
+ form))
+