19.2 Tab Stops

For typing in tables, you can use Text mode’s definition of TAB, tab-to-tab-stop. This command inserts indentation before point, enough to reach the next tab stop column. Even if you are not in Text mode, this function is associated with M-i anyway.

You can arbitrarily set the tab stops used by M-i. They are stored as a list of column-numbers in increasing order in the variable tab-stop-list.

The convenient way to set the tab stops is using M-x edit-tab-stops, which creates and selects a buffer containing a description of the tab stop settings. You can edit this buffer to specify different tab stops, and then type C-c C-c to make those new tab stops take effect. In the tab stop buffer, C-c C-c runs the function edit-tab-stops-note-changes rather than the default save-buffer. edit-tab-stops records which buffer was current when you invoked it, and stores the tab stops in that buffer. Normally all buffers share the same tab stops and changing them in one buffer affects all. If you make tab-stop-list local in one buffer edit-tab-stops in that buffer edits only the local settings.

Below is the text representing ordinary tab stops every eight columns:

        :       :       :       :       :       :
0         1         2         3         4
0123456789012345678901234567890123456789012345678
To install changes, type C-c C-c

The first line contains a colon at each tab stop. The remaining lines help you see where the colons are and tell you what to do.

Note that the tab stops that control tab-to-tab-stop have nothing to do with displaying tab characters in the buffer. See Display Vars, for more information on that.