forward-paragraph: a Goldmine of FunctionsThe forward-paragraph function moves point forward to the end
of the paragraph. It is usually bound to M-} and makes use of a
number of functions that are important in themselves, including
let*, match-beginning, and looking-at.
The function definition for forward-paragraph is considerably
longer than the function definition for forward-sentence
because it works with a paragraph, each line of which may begin with a
fill prefix.
A fill prefix consists of a string of characters that are repeated at the beginning of each line. For example, in Lisp code, it is a convention to start each line of a paragraph-long comment with ‘;;; ’. In Text mode, four blank spaces make up another common fill prefix, creating an indented paragraph. (See Fill Prefix, for more information about fill prefixes.)
The existence of a fill prefix means that in addition to being able to
find the end of a paragraph whose lines begin on the left-most
column, the forward-paragraph function must be able to find the
end of a paragraph when all or many of the lines in the buffer begin
with the fill prefix.
Moreover, it is sometimes practical to ignore a fill prefix that exists, especially when blank lines separate paragraphs. This is an added complication.