[4638] Cleanup of plurals and inheritance relationships in AST

Changed the grammar so that the following "plural" constructs always
parse as an ASTArray:

- funcvalues
- rvalues
- resourceinstances
- anyparams
- params
- caseopts
- casevalues

And the following "singluar" construct never parses as an ASTArray:

- statement

The previous behavior was for these constructs to parse as a scalar
when they represented a single item and an ASTArray when they
contained zero or multiple items.  ("Statement" could sometimes
represent a single item because a single resource declaration could
represent multiple resources).  This complicated other grammar rules
and caused ambiguous handling of nested arrays.

Also made these changes to the AST class hierarchy:

- ResourceInstance no longer derives from ASTArray.  This relationship
  was not meaningful because a ResourceInstance is a (title,
  parameters) pair, not an array, and it produced complications when
  we wanted to represent an array of ResourceInstance objects.

- Resource no longer derives from ResourceReference.  No significant
  functionality was being inherited and the relationship doesn't make
  sense in an AST context.

- ResourceOverride no longer derives from Resource.  No significant
  functionality was being inherited and the relationship doesn't make
  sense in an AST context.

- Resource can now represent a compound resource instance such as
  "notify { foo: ; bar: }".  This saves the parser from having to
  use represent a statement as an array of objects.

- ASTArray's evaluate method never flattens out arrays of arrays.

1 files changed, 16 insertions, 33 deletions

diff --git a/spec/unit/parser/ast/astarray_spec.rb b/spec/unit/parser/ast/astarray_spec.rb
index f79d6c533..8794848b6 100755
--- a/spec/unit/parser/ast/astarray_spec.rb
+++ b/spec/unit/parser/ast/astarray_spec.rb
@@ -23,43 +23,26 @@ describe Puppet::Parser::AST::ASTArray do
     operator.evaluate(@scope)
   end
 
-  it "should evaluate childrens of type ASTArray" do
-    item1 = stub "item1", :is_a? => true
-    item2 = stub "item2"
-    item2.stubs(:is_a?).with(Puppet::Parser::AST).returns(true)
-    item2.stubs(:instance_of?).with(Puppet::Parser::AST::ASTArray).returns(true)
-    item2.stubs(:each).yields(item1)
-
-    item1.expects(:safeevaluate).with(@scope).returns(123)
-
-    operator = Puppet::Parser::AST::ASTArray.new :children => [item2]
-    operator.evaluate(@scope).should == [123]
-  end
-
-  it "should flatten children coming from children ASTArray" do
-    item1 = stub "item1", :is_a? => true
-    item2 = stub "item2"
-    item2.stubs(:is_a?).with(Puppet::Parser::AST).returns(true)
-    item2.stubs(:instance_of?).with(Puppet::Parser::AST::ASTArray).returns(true)
-    item2.stubs(:each).yields([item1])
-
-    item1.expects(:safeevaluate).with(@scope).returns(123)
-
-    operator = Puppet::Parser::AST::ASTArray.new :children => [item2]
-    operator.evaluate(@scope).should == [123]
+  it "should not flatten children coming from children ASTArray" do
+    item = Puppet::Parser::AST::String.new :value => 'foo'
+    inner_array = Puppet::Parser::AST::ASTArray.new :children => [item, item]
+    operator = Puppet::Parser::AST::ASTArray.new :children => [inner_array, inner_array]
+    operator.evaluate(@scope).should == [['foo', 'foo'], ['foo', 'foo']]
   end
 
   it "should not flatten the results of children evaluation" do
-    item1 = stub "item1", :is_a? => true
-    item2 = stub "item2"
-    item2.stubs(:is_a?).with(Puppet::Parser::AST).returns(true)
-    item2.stubs(:instance_of?).with(Puppet::Parser::AST::ASTArray).returns(true)
-    item2.stubs(:each).yields([item1])
-
-    item1.expects(:safeevaluate).with(@scope).returns([123])
+    item = Puppet::Parser::AST::String.new :value => 'foo'
+    item.stubs(:evaluate).returns(['foo'])
+    operator = Puppet::Parser::AST::ASTArray.new :children => [item, item]
+    operator.evaluate(@scope).should == [['foo'], ['foo']]
+  end
 
-    operator = Puppet::Parser::AST::ASTArray.new :children => [item2]
-    operator.evaluate(@scope).should == [[123]]
+  it "should discard nil results from children evaluation" do
+    item1 = Puppet::Parser::AST::String.new :value => 'foo'
+    item2 = Puppet::Parser::AST::String.new :value => 'foo'
+    item2.stubs(:evaluate).returns(nil)
+    operator = Puppet::Parser::AST::ASTArray.new :children => [item1, item2]
+    operator.evaluate(@scope).should == ['foo']
   end
 
   it "should return a valid string with to_s" do