Function: completion-table-with-cache

completion-table-with-cache is a byte-compiled function defined in minibuffer.el.gz.

Signature

(completion-table-with-cache FUN &optional IGNORE-CASE)

Documentation

Create dynamic completion table from function FUN, with cache.

This is a wrapper for completion-table-dynamic that saves the last argument-result pair from FUN, so that several lookups with the same argument (or with an argument that starts with the first one) only need to call FUN once. This can be useful when FUN performs a relatively slow operation, such as calling an external process.

When IGNORE-CASE is non-nil, FUN is expected to be case-insensitive.

View in manual

Probably introduced at or before Emacs version 24.4.

Source Code

;; Defined in /usr/src/emacs/lisp/minibuffer.el.gz
(defun completion-table-with-cache (fun &optional ignore-case)
  "Create dynamic completion table from function FUN, with cache.
This is a wrapper for `completion-table-dynamic' that saves the last
argument-result pair from FUN, so that several lookups with the
same argument (or with an argument that starts with the first one)
only need to call FUN once.  This can be useful when FUN performs a
relatively slow operation, such as calling an external process.

When IGNORE-CASE is non-nil, FUN is expected to be case-insensitive."
  ;; See eg bug#11906.
  (let* (last-arg last-result
         (new-fun
          (lambda (arg)
            (if (and last-arg (string-prefix-p last-arg arg ignore-case))
                last-result
              (prog1
                  (setq last-result (funcall fun arg))
                (setq last-arg arg))))))
    (completion-table-dynamic new-fun)))