$tab-width - Global tab character width
$tab-width integer; Default is 8
-0 < integer <= n
$tab-width defines the default width of a tab character specified in spaces. The default value is used when new files are loaded and created and seeds the variable $buffer-tab-width(5).
Setting tabs to arbitrary widths is possible in MicroEmacs 2009 but you must be aware of a subtle difference that it makes to your file and hence to your editing. When you start MicroEmacs 2009, the tab width is set to the default (usually every 8th column) for the tab character (CTRL-I). As long as you stay with the default, every time you insert the tab character, a CTRL-I get inserted. Hence, you logically have a single character which might appear to be several spaces on the screen (or the output) depending upon the column location of the tab character. This means that to remove the spacing you have to delete a single character -- the tab character.
On the other hand, the moment you explicitly set the tab interval (even if it is to the default value), MicroEmacs 2009 handles the tab character by expanding the character into the required number of spaces to move you to the appropriate column. In this case, to remove the spacing you have to delete the appropriate number of spaces inserted by M-e to get you to the right column.
The operating mode of the tab expansion is controlled by the tab(2m) mode.
The November 2004 version of MicroEmacs removed the existing variables $tabwidth and $tabsize which were ambiguous. The existing variable scope was global which caused problems when moving to buffers with different tab width properties. The variables have been replaced with $tab-width and $buffer-tab-width(5). The indentation which was previously controlled by the tab width has been replaced with $indent-width(5) and $buffer-indent-width(5).
(c) Copyright JASSPA 2009
Last Modified: 2009/08/29
Generated On: 2009/10/12