Regex BNF Grammar
You can see one for Perl regexp (displayed a little more in detail here, as posted by edg)
http://web.archive.org/web/20090129224504/http://faqts.com/knowledge_base/view.phtml/aid/25718/fid/200
To post them on-site:
CMPT 384 Lecture Notes Robert D. Cameron November 29 - December 1, 1999
BNF Grammar of Regular Expressions
Following the precedence rules given previously, a BNF grammar for Perl-style regular expressions can be constructed as follows.
<RE> ::= <union> | <simple-RE>
<union> ::= <RE> "|" <simple-RE>
<simple-RE> ::= <concatenation> | <basic-RE>
<concatenation> ::= <simple-RE> <basic-RE>
<basic-RE> ::= <star> | <plus> | <elementary-RE>
<star> ::= <elementary-RE> "*"
<plus> ::= <elementary-RE> "+"
<elementary-RE> ::= <group> | <any> | <eos> | <char> | <set>
<group> ::= "(" <RE> ")"
<any> ::= "."
<eos> ::= "$"
<char> ::= any non metacharacter | "\" metacharacter
<set> ::= <positive-set> | <negative-set>
<positive-set> ::= "[" <set-items> "]"
<negative-set> ::= "[^" <set-items> "]"
<set-items> ::= <set-item> | <set-item> <set-items>
<set-items> ::= <range> | <char>
<range> ::= <char> "-" <char>
via VonC.
--- Knud van Eeden --- 21 October 2003 - 03:22 am --------------------
PERL:Search/Replace:Regular Expression:Backus Naur Form:What is possible BNF for regular expression?
expression = term
term | expression
term = factor
factor term
factor = atom
atom metacharacter
atom = character
.
( expression )
[ characterclass ]
[ ^ characterclass ]
{ min }
{ min , }
{ min , max }
characterclass = characterrange
characterrange characterclass
characterrange = begincharacter
begincharacter - endcharacter
begincharacter = character
endcharacter = character
character =
anycharacterexceptmetacharacters
\ anycharacterexceptspecialcharacters
metacharacter = ?
* {=0 or more, greedy}
*? {=0 or more, non-greedy}
+ {=1 or more, greedy}
+? {=1 or more, non-greedy}
^ {=begin of line character}
$ {=end of line character}
$` {=the characters to the left of the match}
$' {=the characters to the right of the match}
$& {=the characters that are matched}
\t {=tab character}
\n {=newline character}
\r {=carriage return character}
\f {=form feed character}
\cX {=control character CTRL-X}
\N {=the characters in Nth tag (if on match side)}
$N{=the characters in Nth tag (if not on match side)}
\NNN {=octal code for character NNN}
\b {=match a 'word' boundary}
\B {=match not a 'word' boundary}
\d {=a digit, [0-9]}
\D {=not a digit, [^0-9]}
\s {=whitespace, [ \t\n\r\f]}
\S {=not a whitespace, [^ \t\n\r\f]}
\w {='word' character, [a-zA-Z0-9_]}
\W {=not a 'word' character, [^a-zA-Z0-9_]}
\Q {=put a quote (de-meta) on characters, until \E}
\U {=change characters to uppercase, until \E}
\L {=change characters to uppercase, until \E}
min = integer
max = integer
integer = digit
digit integer
anycharacter = ! " # $ % & ' ( ) * + , - . / :
; < = > ? @ [ \ ] ^ _ ` { | } ~
0 1 2 3 4 5 6 7 8 9
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
a b c d e f g h i j k l m n o p q r s t u v w x y z
---
[book: see also: Bucknall, Julian - the Tomes of Delphi: Algorithms
and Datastructures - p. 37 - 'Using regular expressions' -
http://www.amazon.com/exec/obidos/tg/detail/-
/1556227361/qid=1065748783/sr=1-1/ref=sr_1_1/002-0122962-7851254?
v=glance&s=books]
---
---
Internet: see also:
---
Compiler: Grammar: Expression: Regular: Which grammar defines set of
all regular expressions? [BNF]
http://www.faqts.com/knowledge_base/view.phtml/aid/25950/fid/1263
---
Perl Regular Expression: Quick Reference 1.05
http://www.erudil.com/preqr.pdf
---
Top: Computers: Programming: Languages: Regular Expressions: Perl
http://dmoz.org/Computers/Programming/Languages/Regular_Expressions/Per
l/
---
TSE: Search/Replace:Regular Expression:Backus Naur Form:What is
possible BNF for regular expression?
http://www.faqts.com/knowledge_base/view.phtml/aid/25714/fid/1236
---
Delphi: Search: Regular expression: Create: How to create a regular
expression parser in Delphi?
http://www.faqts.com/knowledge_base/view.phtml/aid/25645/fid/175
---
Delphi: Search: Regular expression: How to add regular expression
searching to Delphi? [Systools]
http://www.faqts.com/knowledge_base/view.phtml/aid/25295/fid/175
----------------------------------------------------------------------
via Ed Guinness.