Provide generalized variables in core Elisp.

[bpt/emacs.git] / lisp / emacs-lisp / macroexp.el

diff --git a/lisp/emacs-lisp/macroexp.el b/lisp/emacs-lisp/macroexp.el
index 95fe43a..6275fd1 100644 (file)
--- a/lisp/emacs-lisp/macroexp.el
+++ b/lisp/emacs-lisp/macroexp.el
@@ -263,7 +263,7 @@ definitions to shadow the loaded ones for use in file byte-compilation."
    ((memq (car-safe then) '(if cond)) (macroexp-if `(not ,test) else then))
    (t `(if ,test ,then ,else))))
 
-(defmacro macroexp-let² (test var exp &rest exps)
+(defmacro macroexp-let2 (test var exp &rest exps)
   "Bind VAR to a copyable expression that returns the value of EXP.
 This is like `(let ((v ,EXP)) ,EXPS) except that `v' is a new generated
 symbol which EXPS can find in VAR.
@@ -280,6 +280,27 @@ be skipped; if nil, as is usual, `macroexp-const-p' is used."
          (macroexp-let* (list (list ,var ,expsym))
                         ,bodysym)))))
 
+(defun macroexp--maxsize (exp size)
+  (cond ((< size 0) size)
+        ((symbolp exp) (1- size))
+        ((stringp exp) (- size (/ (length exp) 16)))
+        ((vectorp exp)
+         (dotimes (i (length exp))
+           (setq size (macroexp--maxsize (aref exp i) size)))
+         (1- size))
+        ((consp exp)
+         ;; We could try to be more clever with quote&function,
+         ;; but it is difficult to do so correctly, and it's not obvious that
+         ;; it would be worth the effort.
+         (dolist (e exp)
+           (setq size (macroexp--maxsize e size)))
+         (1- size))
+        (t -1)))
+
+(defun macroexp-small-p (exp)
+  "Return non-nil if EXP can be considered small."
+  (> (macroexp--maxsize exp 10) 0))
+
 (defsubst macroexp--const-symbol-p (symbol &optional any-value)
   "Non-nil if SYMBOL is constant.
 If ANY-VALUE is nil, only return non-nil if the value of the symbol is the