Commit 6b4a327f authored by Joerg-Cyril Hoehle's avatar Joerg-Cyril Hoehle
Browse files

first-time-p bugfix: return-code :body must return list of forms

if-first-time not declared obsolete
documentation strings for (iter:display-iterate-clauses) complete

parent 42fc807b
......@@ -1251,7 +1251,7 @@ not part of Jonathan Amsterdam's original design.
@deffn Clause first-iteration-p
Returns @code{t} in the first cycle of the loop, otherwise @code{nil}.
Returns @code{t} in the first iteration of the loop, otherwise @code{nil}.
@end deffn
......@@ -2354,16 +2354,23 @@ e.g. (DSETQ (VALUES (a . b) nil c) form)"
(mapc #'local-binding-check forms)
(return-code :final-protected (copy-list forms)))
;;; (if (FIRST-TIME-P) ...) returns true for the first time it is evaluated
;;; (IF-FIRST-TIME then &optional else)
(def-special-clause if-first-time (then &optional else)
"Evaluate branch depending on whether this clause if met for the first time"
(return-code :body (list
(if-1st-time (list (walk-expr then))
(if else (list (walk-expr else)))))))
(def-special-clause FIRST-TIME-P ()
(let ((first-time-var (make-var-and-binding 'first-time t :type 'boolean)))
(return-code :body `(if ,first-time-var
(setf ,first-time-var nil)
"True when evaluated for the first time"
(return-code :body (list (if-1st-time '(t)))))
;;; (if (FIRST-ITERATION-P) ...) returns true in the first iteration of the loop
(def-special-clause FIRST-ITERATION-P ()
"True within first iteration through the body"
;; Like (with ,var = t) (after-each (setq ,var nil))
;; except all these clauses shares a single binding.
(let* ((entry (make-shared-binding 'first-iteration t :type 'boolean))
(step-body nil)
(first-usage (not (cddr entry)))
......@@ -3597,12 +3604,6 @@ e.g. (DSETQ (VALUES (a . b) nil c) form)"
;;; Junk.
;;; Obsolete, use (if (first-time-p) ...)
;;; (IF-FIRST-TIME then &optional else)
(def-special-clause if-first-time (then &optional else)
(warn "if-first-time is obsolete, use (if (first-time-p) ...) instead")
(return-code :body (list (if-1st-time (list (walk-expr then))
(list (walk-expr else))))))
;;;;;;; For Gnu Emacs ;;;;;;;
;;; Local variables:
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