diff options
Diffstat (limited to 'doc/emacs/search.texi')
| -rw-r--r-- | doc/emacs/search.texi | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/doc/emacs/search.texi b/doc/emacs/search.texi index e997e1b2fe4..9ba425f2d21 100644 --- a/doc/emacs/search.texi +++ b/doc/emacs/search.texi @@ -953,8 +953,8 @@ features used mainly in Lisp programs. @dfn{special constructs} and the rest are @dfn{ordinary}. An ordinary character matches that same character and nothing else. The special characters are @samp{$^.*+?[\}. The character @samp{]} is special if -it ends a character alternative (see below). The character @samp{-} -is special inside a character alternative. Any other character +it ends a bracket expression (see below). The character @samp{-} +is special inside a bracket expression. Any other character appearing in a regular expression is ordinary, unless a @samp{\} precedes it. (When you use regular expressions in a Lisp program, each @samp{\} must be doubled, see the example near the end of this @@ -1036,11 +1036,12 @@ you search for @samp{a.*?$} against the text @samp{abbab} followed by a newline, it matches the whole string. Since it @emph{can} match starting at the first @samp{a}, it does. +@cindex bracket expression @cindex set of alternative characters, in regular expressions @cindex character set, in regular expressions @item @kbd{[ @dots{} ]} -is a @dfn{set of alternative characters}, or a @dfn{character set}, -beginning with @samp{[} and terminated by @samp{]}. +is a @dfn{bracket expression} (a.k.a.@: @dfn{set of alternative +characters}), which matches one of a set of characters. In the simplest case, the characters between the two brackets are what this set can match. Thus, @samp{[ad]} matches either one @samp{a} or @@ -1060,7 +1061,7 @@ Greek letters. @cindex character classes, in regular expressions You can also include certain special @dfn{character classes} in a character set. A @samp{[:} and balancing @samp{:]} enclose a -character class inside a set of alternative characters. For instance, +character class inside a bracket expression. For instance, @samp{[[:alnum:]]} matches any letter or digit. @xref{Char Classes,,, elisp, The Emacs Lisp Reference Manual}, for a list of character classes. @@ -1128,7 +1129,7 @@ no preceding expression on which the @samp{*} can act. It is poor practice to depend on this behavior; it is better to quote the special character anyway, regardless of where it appears. -As a @samp{\} is not special inside a set of alternative characters, it can +As a @samp{\} is not special inside a bracket expression, it can never remove the special meaning of @samp{-}, @samp{^} or @samp{]}. You should not quote these characters when they have no special meaning. This would not clarify anything, since backslashes |