This section describes two commands that indent the current line based on the contents of previous lines.
This command inserts whitespace at point, extending to the same column as the next indent point of the previous nonblank line. An indent point is a non-whitespace character following whitespace. The next indent point is the first one at a column greater than the current column of point. For example, if point is underneath and to the left of the first non-blank character of a line of text, it moves to that column by inserting whitespace.
If the previous nonblank line has no next indent point (i.e., none at a
great enough column position), indent-relative either does
nothing (if unindented-ok is non-nil) or calls
tab-to-tab-stop. Thus, if point is underneath and to the right
of the last column of a short line of text, this command ordinarily
moves point to the next tab stop by inserting whitespace.
If first-only is non-nil, only the first indent point is
considered.
The return value of indent-relative is unpredictable.
In the following example, point is at the beginning of the second line:
This line is indented twelve spaces. ∗The quick brown fox jumped.
Evaluation of the expression (indent-relative nil) produces the
following:
This line is indented twelve spaces.
∗The quick brown fox jumped.
In this next example, point is between the ‘m’ and ‘p’ of ‘jumped’:
This line is indented twelve spaces. The quick brown fox jum∗ped.
Evaluation of the expression (indent-relative nil) produces the
following:
This line is indented twelve spaces. The quick brown fox jum ∗ped.
This command indents the current line like the previous nonblank line,
by calling indent-relative with t as the
first-only argument. The return value is unpredictable.
If the previous nonblank line has no indent points beyond the current column, this command does nothing.