0005259: Support for extended regular expressions

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Date Submitted

Last Update

0005259

OCaml

OCaml general

public

2011-04-28 13:28

2011-04-29 11:22

Reporter

gerd

Assigned To

Priority

normal

Severity

feature

Reproducibility

N/A

Status

acknowledged

Resolution

open

Platform

all

OS Version

all

Product Version

3.12.0

Target Version

Fixed in Version

Summary

0005259: Support for extended regular expressions

Description

The idea is to have a new function Str.eregexp that parses the "extended" syntax. The main difference so far looks tiny, but has a lot of impact on the readability of code. Essentially, ( ) | no longer need a backslash. The reference standard here are POSIX extended regular expressions. It also defines the {bound} construct.

The extended syntax is nowadays used in most other programming languages. It feels like stepping back when using ocaml.

When introducing this, it might also be a good idea to define/reserve a generic way for extending the syntax later, e.g. for additional assertions and non-capturing groups, as suggested by other bug reporters. Using more backslash sequences does not look very elegant. More readable seems to be:

- Character classes like [[:name:]]
- Group with modifiers: (?switches:regexp), e.g.
(?i:regexp) for a case-insensitive non-capturing group
- Named option or assertion (*NAME)

Additional Information

One would also need Str.equote.

A good reference comparing regexp flavors by syntax: http://www.regular-expressions.info/refflavors.html [^]

Issue History
Date Modified	Username	Field	Change
2011-04-28 13:28	gerd	New Issue
2011-04-29 11:22	doligez	Status	new => acknowledged

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