Add a doc attribute to AST nodes and fill it with the last seen comments

The lexer maintains a stack of last seen comments.
On blank lines the lexer flush the comments.
On each opening brace the lexer enters a new stack level.
On each block AST nodes, the stack is popped.

Each AST nodes has a doc property that is filled with the
last seen comments on node creation (in fact only on important node
creation representing statements).

Signed-off-by: Brice Figureau <brice-puppet@daysofwonder.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/lib/puppet/parser/ast.rb b/lib/puppet/parser/ast.rb
index ddf88521c..303d75bac 100644
--- a/lib/puppet/parser/ast.rb
+++ b/lib/puppet/parser/ast.rb
@@ -12,8 +12,23 @@ class Puppet::Parser::AST
 
     include Puppet::Util::Errors
     include Puppet::Util::MethodHelper
+    include Puppet::Util::Docs
+
     attr_accessor :line, :file, :parent, :scope
 
+    # don't fetch lexer comment by default
+    def use_docs
+        self.class.use_docs
+    end
+
+    # allow our subclass to specify they want documentation
+    class << self
+       attr_accessor :use_docs
+       def associates_doc
+         self.use_docs = true
+       end
+    end
+
     # Does this ast object set something?  If so, it gets evaluated first.
     def self.settor?
         if defined? @settor