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This section describes some variables that hold regular expressions used for certain purposes in editing:
This is the regular expression describing line-beginnings that separate pages. The default value is
"^\014"
(i.e.,"^^L"
or"^\C-l"
); this matches a line that starts with a formfeed character.
The following two regular expressions should not assume the match always starts at the beginning of a line; they should not use ‘^’ to anchor the match. Most often, the paragraph commands do check for a match only at the beginning of a line, which means that ‘^’ would be superfluous. When there is a nonzero left margin, they accept matches that start after the left margin. In that case, a ‘^’ would be incorrect. However, a ‘^’ is harmless in modes where a left margin is never used.
This is the regular expression for recognizing the beginning of a line that separates paragraphs. (If you change this, you may have to change
paragraph-start
also.) The default value is"[ \t\f]*$"
, which matches a line that consists entirely of spaces, tabs, and form feeds (after its left margin).
This is the regular expression for recognizing the beginning of a line that starts or separates paragraphs. The default value is
"[ \t\n\f]"
, which matches a line starting with a space, tab, newline, or form feed (after its left margin).
This is the regular expression describing the end of a sentence. (All paragraph boundaries also end sentences, regardless.) The default value is:
"[.?!][]\"')}]*\\($\\| $\\|\t\\| \\)[ \t\n]*"This means a period, question mark or exclamation mark, followed optionally by a closing parenthetical character, followed by tabs, spaces or new lines.
For a detailed explanation of this regular expression, see Regexp Example.