Re: thunk.el: Document that thunk-force == funcall?

[Michael Heerdegen]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> I don't have any concrete real-life examples. [...]

Actually I have one real-life example:

#+begin_src emacs-lisp
(defun el-search--change-p (posn revision)
  ;; Non-nil when sexp after POSN is part of a change
  (if (buffer-modified-p)
      (if (eq this-command 'el-search-pattern)
          (user-error "Buffer is modified - please save")
        nil)
    (save-restriction
      (widen)
      (let ((changes (el-search--changes-from-diff-hl revision))
            (sexp-end (el-search--end-of-sexp posn))
            (atomic? (thunk-delay (el-search--atomic-p
                                   (save-excursion (goto-char posn)
                                                   (el-search-read 
(current-buffer)))))))
        (while (and changes (or (< (cdar changes) posn)
                                (and
                                 ;; a string spanning multiple lines is a 
change even when not all
                                 ;; lines are changed
                                 (< (cdar changes) sexp-end)
                                 (not (thunk-force atomic?)))))
          (pop changes))
        (and changes (or (<= (caar changes) posn)
                         (and (thunk-force atomic?)
                              (<= (caar changes) sexp-end))))))))
#+end_src

I can live with `thunk-force' here; being able to use it as a function
would make the code a bit more readable.  Although, hiding the
function's nature as a thunk might not be good OTOH.

A thunk or fbound function have the advantage that they can be passed
without forcing.  Contrary to symbols bound with `thunk-let'; a thunk
passed to a function this way is forced before that function is called,
even when the thunk's result is never used.  That's why I'm wondering
whether `thunk-let' is as cool as I had thought.

Ok, anything else to say, apart from the empty string?


Regards,

Michael.