Variable: whitespace-indentation-regexp
whitespace-indentation-regexp is a customizable variable defined in
whitespace.el.gz.
Value
("^ *\\(\\( \\{%d\\}\\)+\\)[^\n ]" . "^ *\\( +\\)[^\n]")
Documentation
Specify regexp for tab-width or more SPACEs at beginning of line.
It is a cons where the cons car is used for SPACEs visualization and the cons cdr is used for TABs visualization.
Used when whitespace-style includes indentation,
indentation::tab or indentation::space.
Source Code
;; Defined in /usr/src/emacs/lisp/whitespace.el.gz
(defcustom whitespace-indentation-regexp
'("^\t*\\(\\( \\{%d\\}\\)+\\)[^\n\t]"
. "^ *\\(\t+\\)[^\n]")
"Specify regexp for `tab-width' or more SPACEs at beginning of line.
It is a cons where the cons car is used for SPACEs visualization
and the cons cdr is used for TABs visualization.
Used when `whitespace-style' includes `indentation',
`indentation::tab' or `indentation::space'."
:type '(cons (string :tag "Indentation SPACEs")
(regexp :tag "Indentation TABs"))
:group 'whitespace)