I only played a little with PetitParser but I think the answer is in PetitXml>>#element. You see in the action block that it compares the "qualified" of the open and close tags and if they're different it returns a PPFailure. It also takes care of the inlineTag in the same block by asking if the fifth node is '/>'. element "[39] element ::= EmptyElemTag | STag content ETag" ^ $< asParser , qualified , attributes , whitespace optional , ('/>' asParser / ($> asParser , content , [ :stream | stream position ] asParser , '</' asParser , qualified , whitespace optional , $> asParser)) ==> [ :nodes | *nodes fifth = '/>'* ifTrue: [ Array with: nodes second with: nodes third with: #() ] ifFalse: [ *nodes second = nodes fifth fifth* ifTrue: [ Array with: nodes second with: nodes third with: nodes fifth second ] ifFalse: [ PPFailure message: 'Expected </' , nodes second qualifiedName , '>' at: nodes fifth third ] ] ] I hope this helps. Cheers, Richo On Mon, Apr 25, 2011 at 6:42 PM, Esteban Lorenzano <estebanlm@gmail.com>wrote:
Hi Lukas, all I'm finally working on a HTML petit parser (a very basic one, based on XML petit parser) and I have a serious problem (well... besides my complete ignorance about petit parser, he...) I need to match this pattern:
openTag, contents, closeTag (that will be something like "<html> ... </html>") inlineTag (that will be something like "<br/>") openTag (that will be something like "<link ...>" or "<img src='anUrl'>")
so, after try some variants... I came with this construct:
element "[39] element ::= EmptyElemTag | STag content ETag"
^(self inlineTag / (self openTag, content, self closeTag) / self openTag) ==> [ :nodes | ].
openTag ^ $< asParser, qualified, whitespace optional, attributes, whitespace optional, $> asParser
inlineTag ^ $< asParser, qualified, whitespace optional, attributes, whitespace optional, '/>' asParser
closeTag ^'</' asParser , qualified , whitespace optional , $> asParser
so... the problem here is that the statement
self openTag, contents, self closeTag
matchs with
... <link ...> </html>
and for that reason, the resulting tree is invalid.
So, I need a way to ensure the openTag name is equal to the closeTag name.
How can I do that?
Cheers, Esteban