(sh-prev-thing): Massage to untangle the

control flow a bit, simplify another bit, and add comments.

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 582bf3f93b247b183ce8b57405d52ed2df1d2b56..6c00cbada7ab5853aa60138917c7e5a0969290d5 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2006-10-03  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+       * progmodes/sh-script.el (sh-prev-thing): Massage to untangle the
+       control flow a bit, simplify another bit, and add comments.
+
 2006-10-03  David Kastrup  <dak@gnu.org>
 
        * help.el (describe-mode): For clicks on mode-line, use "@"

diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index 089715b4836117bc6fac15cf614f799b285a3fba..e1c175489590edfa443f196810b1c014c3e548fc 100644 (file)
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -2460,55 +2460,49 @@ we go to the end of the previous line and do not check for continuations."
   ;;
   (if (bolp)
       nil
-    (let (c min-point
-         (start (point)))
-      (save-restriction
-       (narrow-to-region
-       (if (sh-this-is-a-continuation)
-           (setq min-point (sh-prev-line nil))
-         (save-excursion
-           (beginning-of-line)
-           (setq min-point (point))))
-       (point))
-       (skip-chars-backward " \t;")
-       (unless (looking-at "\\s-*;;")
-         (skip-chars-backward "^)}];\"'`({[")
-         (setq c (char-before)))
-       (sh-debug "stopping at %d c is %s  start=%d min-point=%d"
-                 (point) c start min-point)
-       (if (< (point) min-point)
-           (error "point %d < min-point %d" (point) min-point))
-       (cond
-        ((looking-at "\\s-*;;")
-         ;; (message "Found ;; !")
-         ";;")
-        ((or (eq c ?\n)
-             (eq c nil)
-             (eq c ?\;))
-        (let (done kwd next
-              (boundary (point)))
-          (skip-chars-forward " \t\n\\\\")
-          (while (and (not done) (not (eobp)))
-            (if next (setq boundary next))
-            ;; skip forward over white space newline and \ at eol
-            (sh-debug "Now at %d   start=%d" (point) start)
-            (if (>= (point) start)
-                (progn
-                  (sh-debug "point: %d >= start: %d" (point) start)
-                  nil)
-              (setq kwd (sh-get-word))
-              (unless (eobp) (forward-char 1))
-              (if (member kwd (sh-feature sh-leading-keywords))
-                  (setq next (point))
-                (setq done t)))
-            (skip-chars-forward " \t\n\\\\"))
-          (goto-char boundary)
-          kwd))
-        (t
-         ;; c  -- return a string
-         (char-to-string c)
-         ))
-       ))))
+    (let ((start (point))
+          (min-point (if (sh-this-is-a-continuation)
+                         (sh-prev-line nil)
+                       (line-beginning-position))))
+      (skip-chars-backward " \t;" min-point)
+      (if (looking-at "\\s-*;;")
+          ;; (message "Found ;; !")
+          ";;"
+        (skip-chars-backward "^)}];\"'`({[" min-point)
+        (let ((c (if (> (point) min-point) (char-before))))
+          (sh-debug "stopping at %d c is %s  start=%d min-point=%d"
+                    (point) c start min-point)
+          (if (not (memq c '(?\n nil ?\;)))
+              ;; c     -- return a string
+              (char-to-string c)
+            ;; Return the leading keyword of the "command" we supposedly
+            ;; skipped over.  Maybe we skipped too far (e.g. past a `do' or
+            ;; `then' that precedes the actual command), so check whether
+            ;; we're looking at such a keyword and if so, move back forward.
+            (let ((boundary (point))
+                  kwd next)
+              (while
+                  (progn
+                    ;; Skip forward over white space newline and \ at eol.
+                    (skip-chars-forward " \t\n\\\\" start)
+                    (if (>= (point) start)
+                        (progn
+                          (sh-debug "point: %d >= start: %d" (point) start)
+                          nil)
+                      (if next (setq boundary next))
+                      (sh-debug "Now at %d   start=%d" (point) start)
+                      (setq kwd (sh-get-word))
+                      ;; The reason for this next line is unclear.
+                      ;; <md5i@cs.cmu.edu> says "the need for this was
+                      ;; expermientally determined".  --Stef
+                      (when (< (point) start) (forward-char 1))
+                      (if (member kwd (sh-feature sh-leading-keywords))
+                          (progn
+                            (setq next (point))
+                            t)
+                        nil))))
+              (goto-char boundary)
+              kwd)))))))
 
 
 (defun sh-this-is-a-continuation ()