regular expression engine
- perlre - Perl regular expressions
- Regular Expressions/Perl-Compatible Regular Expressions
- Regular Expressions/POSIX-Extended Regular Expressions
- Understanding Regular Expressions
- faqts : Computers : Programming : Languages : Tse : Parser
- PERL:Search/Replace:Regular Expression:Backus Naur Form:What is possible BNF for regular expression?
- Perl Style Regular Expressions in Prolog
- Regex BNF Grammar
- Lecture 32: BNF Describing Language Syntax
- Discussion 12: Regular Expressions & BNF
- Regex BNF Grammar
- MarpaX-Regex Public
- Perl Compatible Regular Expressions (PCRE) Documentation
- translate BNF grammar to sequence of RegEx'es
- BNF Notation in Compiler Design
- Regular Expressions and BNF (Backus Naur Form)
- Introduction to Grammars and BNF
- 0:16 / 7:50 How to write BNF and EBNF grammar
- Backus-Naur Form
- 0:09 / 38:45 BNF, EBNF & Syntax Graphs
- Programming Language Syntax 1 - Backus-Naur Form (BNF)
- 22. BNF (BACKUS NAUR FORM)
- 0:02 / 8:36 • Purpose of a Parse Tree Parse Trees
- 0:54 / 14:57 Parsing Explained - Computerphile
- 0:30 / 14:01 Building a Parser from scratch. Lecture [1/18]: Tokenizer | Parser
perlre - Perl regular expressions
Perl has a richer and more predictable syntax than even the POSIX Extended Regular Expressions syntax. An example of its predictability is that \ always quotes a non-alphanumeric character. An example of something that is possible to specify with Perl but not POSIX is whether part of the match wanted to be greedy or not. For instance in the pattern /a.*b/, the .* will match as much as it can, while in the pattern /a.*?b/, .*? will match as little. So given the string "a bad dab", the first pattern will match the whole string, and the second will only match "a b".
The more advanced "extended" regular expressions can sometimes be used with Unix utilities by including the command line flag "-E". Other Unix utilities, like awk, use it by default. The main difference is that some backslashes are removed: \{…\} becomes {…} and \(…\) becomes (…). Examples:
I'd like to tell you a story about a friend of mine, Fred. Because of the nature of the story, I'll talk a lot about Perl regular expressions and how they really work behind the scenes. To follow the story, I'll assume that you know Perl at least as well as Fred (which is not saying a lot, since he doesn't know it all that well, although he thinks he does).
TSE: Search/Replace:Regular Expression:Backus Naur Form:What is possible BNF for regular expression?
PERL:Search/Replace:Regular Expression:Backus Naur Form:What is possible BNF for regular expression?
Case Study: Implementing Perl Style Regular Expressions
Is there any BNF grammar for regular expression?
Lecture 32: BNF Describing Language Syntax
This is an online worksheet that you can work on during discussions. Your work is not graded and you do not need to submit anything.
Is there any BNF grammar for regular expression?
MarpaX-Regex Public
Perl Compatible Regular Expressions (PCRE) Documentation
Simple program to read in a BNF grammar and create a regular expression for the root element. This can be used to create a validator.
BNF Notation in Compiler Design
Video - BNF
An introduction to Regular Expressions, the use of Formal Language and BNF including Syntax Diagrams. Suitable for AQA A-Level Computer Science
An introduction to grammars and specifically Backus Naur Form (BNF)
How to write BNF and EBNF grammar for a given language
BNF, or Backus-Naur form is an elegant and succinct way of expressing a grammar in very few lines. Find out more about how this works in today's random Wednesday tutorial!
This video is having an analysis of BNF, EBNF & Syntax Graphs. This is a live recorded video tutorial. So you can easily understand how to write BNF & EBNF grammar rules and conversion parts of them with examples. Also you can study how to visualize the BNF & EBNF grammar rules in Syntax Graphs.
his is a short introduction to the Backus-Naur Form of describing a Context-Free Grammar, with some simple examples.
This explain the notation used for representing Grammar i.e BNF Form.
An explanation of parse trees intended for students learning about BNF grammars and programming languages.
How ambiguity is dangerous! Professor Brailsford simplifies parsing.
0:30 / 14:01 Building a Parser from scratch. Lecture [1/18]: Tokenizer | Parser
