[asterisk-dev] Better pattern matching

[Clive Nicolson]

On Wed, 1 Aug 2007, Clod Patry wrote:

> you probably are searching for RFC 2705 ?
>
> That would be great if Asterisk could support that kind of
> digitmaps/patterns.
>
>

Hi,

I have some code which roughly translates rfc 2705 digitmaps into a posix 
extended regexpression:

The DigitMap is translated to a posix extended regexpression. The dialplan 
regexression is then placed between ^( and )$ so that is is anchored at both 
ends. The DigitMap is case insensitive. A posix_extended_regexpression is 
case sensitive.

dialplan syntax in YACC/Bison format:

dialplan	: 0:DigitMap
 		| 1:posix_extended_regexpression
 		;

DigitMap	: DigitStringT
 		| '(' DigitStringTList ')'
 		;

DigitStringTList: DigitStringT
 		| DigitStringT '|' DigitStringTList
 		;

DigitStringT	: DigitString
 		| DigitString 't'
 		;

DigitString	: DigitStringElement
 		| DigitString DigitStringElement
 		;

DigitStringElement	: DigitPosition
 		| DigitPosition '.'
 		;

DigitPosition	: DigitMapLetter
 		| DigitMapRange
 		;

DigitMapRange	: 'x'
 		| '[' DigitLetters ']'
 		;

DigitLetters	: DigitLetter
 		| DigitLetter DigitLetters
 		;

DigitLetter	: DigitMapLetter
 		| DIGIT '-' DIGIT
 		;

DigitMapLetter	: DIGIT
 		| '#' | '*' | 'a' | 'b' | 'c' | 'd'
 		;

DIGIT		: '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
 		;

Example:

0:(0T|8[1-3]xx)

Matches digit string of the form 0 or 8 followed by 1,2 or and 2 more digits.

If anyone would like the code I can post it to the bug tracker.

Clive