Is arbitrary buffer position at the beginning of a line?

Question

What's the simplest way to check whether a given point value p is at the beginning of some line or not? Is there anything simpler than (save-excursion (goto-char p) (= p (point-at-bol))) or (member (char-before p) '(nil \n))?

Answer 1

You can also use the function bolp:

bolp is a built-in function in `../editfns.c'.

(bolp)

Return t if point is at the beginning of a line.

This function does not change global state, including the match data.

Usually you get a buffer position via (point), thus simply issuing (bolp) will be enough. If the point has been moved, use goto-char in advance.