4 Customizing Indentation

The vhdl-offsets-alist variable is where you customize all your indentations. You simply need to decide what additional offset you want to add for every syntactic symbol. You can use the command C-c O (vhdl-set-offset) as the way to set offsets, both interactively and from your mode hook. Also, you can set up styles of indentation. Most likely, you’ll find one of the pre-defined styles will suit your needs, but if not, this section will describe how to set up basic editing configurations. See Styles, for an explanation of how to set up named styles.

As mentioned previously, the variable vhdl-offsets-alist is an association list between syntactic symbols and the offsets to be applied for those symbols. In fact, these offset values can be an integer, a function or variable name, or one of the following symbols: +, -, ++, --, *, or /. The symbol values have the following meanings:

• + – 1 x vhdl-basic-offset
• - – -1 x vhdl-basic-offset
• ++ – 2 x vhdl-basic-offset
• -- – -2 x vhdl-basic-offset
• * – 0.5 x vhdl-basic-offset
• / – -0.5 x vhdl-basic-offset

So, for example, because most of the default offsets are defined in terms of +, -, and 0, if you like the general indentation style, but you use 2 spaces instead of 4 spaces per level, you can probably achieve your style just by changing vhdl-basic-offset like so (in your .emacs file):

(setq vhdl-basic-offset 2)

To change indentation styles more radically, you will want to change the value associated with the syntactic symbols in the vhdl-offsets-alist variable. First, I’ll show you how to do that interactively, then I’ll describe how to make changes to your .emacs file so that your changes are more permanent.