1
Download GNU Emacs Manual
Transcript
Chapter 23: Editing Programs C-M-e Move to end of current or following defun (end-of-defun). C-M-h Put region around whole current or following defun (mark-defun). 516 The commands to move to the beginning and end of the current defun are C-M-a (beginning-of-defun) and C-M-e (end-of-defun). If you repeat one of these commands, or use a positive numeric argument, each repetition moves to the next defun in the direction of motion. C-M-a with a negative argument −n moves forward n times to the next beginning of a defun. This is not exactly the same place that C-M-e with argument n would move to; the end of this defun is not usually exactly the same place as the beginning of the following defun. (Whitespace, comments, and perhaps declarations can separate them.) Likewise, C-M-e with a negative argument moves back to an end of a defun, which is not quite the same as C-M-a with a positive argument. To operate on the current defun, use C-M-h (mark-defun), which sets the mark at the end of the current defun and puts point at its beginning. See Section 8.2 [Marking Objects], page 90. This is the easiest way to get ready to kill the defun in order to move it to a different place in the file. If you use the command while point is between defuns, it uses the following defun. If you use the command while the mark is already active, it sets the mark but does not move point; furthermore, each successive use of C-M-h extends the end of the region to include one more defun. In C mode, C-M-h runs the function c-mark-function, which is almost the same as mark-defun; the difference is that it backs up over the argument declarations, function name and returned data type so that the entire C function is inside the region. This is an example of how major modes adjust the standard key bindings so that they do their standard jobs in a way better fitting a particular language. Other major modes may replace any or all of these key bindings for that purpose. 23.2.3 Imenu The Imenu facility offers a way to find the major definitions in a file by name. It is also useful in text formatter major modes, where it treats each chapter, section, etc., as a definition. (See Section 25.3 [Tags], page 571, for a more powerful feature that handles multiple files together.) If you type M-x imenu, it reads the name of a definition using the minibuffer, then moves point to that definition. You can use completion to specify the name; the command always displays the whole list of valid names. Alternatively, you can bind the command imenu to a mouse click. Then it displays mouse menus for you to select a definition name. You can also add the buffer’s index to the menu bar by calling imenu-add-menubar-index. If you want to have this menu bar item available for all buffers in a certain major mode, you can do this by adding imenu-addmenubar-index to its mode hook. But if you have done that, you will have to wait a little while each time you visit a file in that mode, while Emacs finds all the definitions in that buffer. When you change the contents of a buffer, if you add or delete definitions, you can update the buffer’s index based on the new contents by invoking the ‘*Rescan*’ item in the menu. Rescanning happens automatically if you set imenu-auto-rescan to a non-nil value. There is no need to rescan because of small changes in the text.
