[augeas-devel] [Augeas] #19: Enhance XPath notation

[Augeas]

#19: Enhance XPath notation
-------------------------+--------------------------------------------------
 Reporter:  lutter       |       Owner:  lutter  
     Type:  enhancement  |      Status:  new     
 Priority:  major        |   Milestone:  wishlist
Component:  Augeas       |     Version:  0.3.0   
 Keywords:               |  
-------------------------+--------------------------------------------------
 Enhance the path expressions that Augeas understands to include constructs
 like


 {{{
          /files/etc/hosts/*[ipaddr = "127.0.0.1"]
          /files/etc/hosts/*[ipaddr = "127.0.0.1"]/alias[last() - 1]
          /augeas/files//error
          /files/etc/puppet/puppet.conf/section[value() = "main"]/vardir
 }}}

 A very rough sketch at a grammar is

 {{{
 PathExpr      ::= (("/" | "//") StepExpr)+
 StepExpr      ::= (Name | "*" | "..") PredicateList
 PredicateList ::= "[" PredExpr "]" *
 PredExpr      ::= ValueTest | PositionTest
 ValueTest     ::= (Name | "value()") "=" ValueLiteral
 PositionTest  ::= Number | "last()" ( "-" Number )
 Name          ::= /[^/[()]+/
 ValueLiteral  ::= '"' /[^"]*/ '"' | "'" /[^']*/ "'" | "nil"
 Number        ::= /[0-9]+/
 }}}

-- 
Ticket URL: <https://fedorahosted.org/augeas/ticket/19>
Augeas <http://augeas.net/>
a configuration API