* gnus-clfns.el (subseq, merge, coerce, butlast): New compiler macros.

[elisp/gnus.git-] / lisp / gnus-clfns.el

diff --git a/lisp/gnus-clfns.el b/lisp/gnus-clfns.el
index 6fed527..e5b2e01 100644 (file)
--- a/lisp/gnus-clfns.el
+++ b/lisp/gnus-clfns.el
@@ -1,5 +1,5 @@
 ;;; gnus-clfns.el --- compiler macros for emulating cl functions
-;; Copyright (C) 2000 Free Software Foundation, Inc.
+;; Copyright (C) 2000, 2001 Free Software Foundation, Inc.
 
 ;; Author: Kastsumi Yamaoka <yamaoka@jpl.org>
 ;; Keywords: cl, compile
@@ -31,6 +31,47 @@
     nil
   (require 'cl)
 
+  (define-compiler-macro butlast (&whole form x &optional n)
+    (if (and (fboundp 'butlast)
+            (subrp (symbol-function 'butlast)))
+       form
+      (if n
+         `(let ((x ,x)
+                (n ,n))
+            (if (and n (<= n 0))
+                x
+              (let ((m (length x)))
+                (or n (setq n 1))
+                (and (< n m)
+                     (progn
+                       (if (> n 0) (setcdr (nthcdr (- (1- m) n) x) nil))
+                       x)))))
+       `(let* ((x ,x)
+               (m (length x)))
+          (and (< 1 m)
+               (progn
+                 (setcdr (nthcdr (- m 2) x) nil)
+                 x))))))
+
+  (define-compiler-macro coerce (&whole form x type)
+    (if (and (fboundp 'coerce)
+            (subrp (symbol-function 'coerce)))
+       form
+      `(let ((x ,x)
+            (type ,type))
+        (cond ((eq type 'list) (if (listp x) x (append x nil)))
+              ((eq type 'vector) (if (vectorp x) x (vconcat x)))
+              ((eq type 'string) (if (stringp x) x (concat x)))
+              ((eq type 'array) (if (arrayp x) x (vconcat x)))
+              ((and (eq type 'character) (stringp x) (= (length x) 1))
+               (aref x 0))
+              ((and (eq type 'character) (symbolp x)
+                    (= (length (symbol-name x)) 1))
+               (aref (symbol-name x) 0))
+              ((eq type 'float) (float x))
+              ((typep x type) x)
+              (t (error "Can't coerce %s to type %s" x type))))))
+
   (define-compiler-macro last (&whole form x &optional n)
     (if (and (fboundp 'last)
             (subrp (symbol-function 'last)))
@@ -53,23 +94,73 @@
             (pop x))
           x))))
 
-  (define-compiler-macro mapc (&whole form fn seq &rest rest)
-    (if (and (fboundp 'mapc)
-            (subrp (symbol-function 'mapc)))
+  (define-compiler-macro merge (&whole form type seq1 seq2 pred &rest keys)
+    (if (and (fboundp 'merge)
+            (subrp (symbol-function 'merge)))
+       form
+      `(let ((type ,type)
+            (seq1 ,seq1)
+            (seq2 ,seq2)
+            (pred ,pred))
+        (or (listp seq1) (setq seq1 (append seq1 nil)))
+        (or (listp seq2) (setq seq2 (append seq2 nil)))
+        (let ((res nil))
+          (while (and seq1 seq2)
+            (if (funcall pred (car seq2) (car seq1))
+                (push (pop seq2) res)
+              (push (pop seq1) res)))
+          (coerce (nconc (nreverse res) seq1 seq2) type)))))
+
+  (define-compiler-macro subseq (&whole form seq start &optional end)
+    (if (and (fboundp 'subseq)
+            (subrp (symbol-function 'subseq)))
        form
-      (if rest
-         `(let* ((fn ,fn)
-                 (seq ,seq)
-                 (args (list seq ,@rest))
-                 (m (apply (function min) (mapcar (function length) args)))
-                 (n 0))
-            (while (< n m)
-              (apply fn (mapcar (function (lambda (arg) (nth n arg))) args))
-              (setq n (1+ n)))
-            seq)
-       `(let ((seq ,seq))
-          (mapcar ,fn seq)
-          seq))))
+      (if end
+         `(let ((seq ,seq)
+                (start ,start)
+                (end ,end))
+            (if (stringp seq)
+                (substring seq start end)
+              (let (len)
+                (if (< end 0)
+                    (setq end (+ end (setq len (length seq)))))
+                (if (< start 0)
+                    (setq start (+ start (or len (setq len (length seq))))))
+                (cond ((listp seq)
+                       (if (> start 0)
+                           (setq seq (nthcdr start seq)))
+                       (let ((res nil))
+                         (while (>= (setq end (1- end)) start)
+                           (push (pop seq) res))
+                         (nreverse res)))
+                      (t
+                       (let ((res (make-vector (max (- end start) 0) nil))
+                             (i 0))
+                         (while (< start end)
+                           (aset res i (aref seq start))
+                           (setq i (1+ i)
+                                 start (1+ start)))
+                         res))))))
+       `(let ((seq ,seq)
+              (start ,start))
+          (if (stringp seq)
+              (substring seq start)
+            (let (len)
+              (if (< start 0)
+                  (setq start (+ start (or len (setq len (length seq))))))
+              (cond ((listp seq)
+                     (if (> start 0)
+                         (setq seq (nthcdr start seq)))
+                     (copy-sequence seq))
+                    (t
+                     (let* ((end (or len (length seq)))
+                            (res (make-vector (max (- end start) 0) nil))
+                            (i 0))
+                       (while (< start end)
+                         (aset res i (aref seq start))
+                         (setq i (1+ i)
+                               start (1+ start)))
+                       res)))))))))
   )
 
 (provide 'gnus-clfns)