diff --git a/lib/puppet/pops/model/model_label_provider.rb b/lib/puppet/pops/model/model_label_provider.rb
index 543d83d49..63c24d484 100644
--- a/lib/puppet/pops/model/model_label_provider.rb
+++ b/lib/puppet/pops/model/model_label_provider.rb
@@ -1,106 +1,106 @@
 # A provider of labels for model object, producing a human name for the model object.
 # As an example, if object is an ArithmeticExpression with operator +, `#a_an(o)` produces "a '+' Expression",
 # #the(o) produces "the + Expression", and #label produces "+ Expression".
 #
 class Puppet::Pops::Model::ModelLabelProvider < Puppet::Pops::LabelProvider
   def initialize
     @@label_visitor ||= Puppet::Pops::Visitor.new(self,"label",0,0)
   end
 
   # Produces a label for the given objects type/operator without article.
   # If a Class is given, its name is used as label
   #
   def label o
     @@label_visitor.visit(o)
   end
 
   def label_Factory o                     ; label(o.current)                    end
   def label_Array o                       ; "Array"                             end
   def label_LiteralInteger o              ; "Literal Integer"                   end
   def label_LiteralFloat o                ; "Literal Float"                     end
   def label_ArithmeticExpression o        ; "'#{o.operator}' expression"        end
   def label_AccessExpression o            ; "'[]' expression"                   end
   def label_MatchExpression o             ; "'#{o.operator}' expression"        end
   def label_CollectExpression o           ; label(o.query)                      end
   def label_EppExpression o               ; "Epp Template"                      end
   def label_ExportedQuery o               ; "Exported Query"                    end
   def label_VirtualQuery o                ; "Virtual Query"                     end
   def label_QueryExpression o             ; "Collect Query"                     end
   def label_ComparisonExpression o        ; "'#{o.operator}' expression"        end
   def label_AndExpression o               ; "'and' expression"                  end
   def label_OrExpression o                ; "'or' expression"                   end
   def label_InExpression o                ; "'in' expression"                   end
   def label_AssignmentExpression o        ; "'#{o.operator}' expression"        end
   def label_AttributeOperation o          ; "'#{o.operator}' expression"        end
   def label_LiteralList o                 ; "Array Expression"                  end
   def label_LiteralHash o                 ; "Hash Expression"                   end
   def label_KeyedEntry o                  ; "Hash Entry"                        end
   def label_LiteralBoolean o              ; "Boolean"                           end
   def label_TrueClass o                   ; "Boolean"                           end
   def label_FalseClass o                  ; "Boolean"                           end
   def label_LiteralString o               ; "String"                            end
   def label_LambdaExpression o            ; "Lambda"                            end
   def label_LiteralDefault o              ; "'default' expression"              end
   def label_LiteralUndef o                ; "'undef' expression"                end
   def label_LiteralRegularExpression o    ; "Regular Expression"                end
   def label_Nop o                         ; "Nop Expression"                    end
   def label_NamedAccessExpression o       ; "'.' expression"                    end
-  def label_NilClass o                    ; "Nil Object"                        end
+  def label_NilClass o                    ; "Undef Value"                       end
   def label_NotExpression o               ; "'not' expression"                  end
   def label_VariableExpression o          ; "Variable"                          end
   def label_TextExpression o              ; "Expression in Interpolated String" end
   def label_UnaryMinusExpression o        ; "Unary Minus"                       end
   def label_UnfoldExpression o            ; "Unfold"                            end
   def label_BlockExpression o             ; "Block Expression"                  end
   def label_ConcatenatedString o          ; "Double Quoted String"              end
   def label_HeredocExpression o           ; "'@(#{o.syntax})' expression"       end
   def label_HostClassDefinition o         ; "Host Class Definition"             end
   def label_NodeDefinition o              ; "Node Definition"                   end
   def label_ResourceTypeDefinition o      ; "'define' expression"               end
   def label_ResourceOverrideExpression o  ; "Resource Override"                 end
   def label_Parameter o                   ; "Parameter Definition"              end
   def label_ParenthesizedExpression o     ; "Parenthesized Expression"          end
   def label_IfExpression o                ; "'if' statement"                    end
   def label_UnlessExpression o            ; "'unless' Statement"                end
   def label_CallNamedFunctionExpression o ; "Function Call"                     end
   def label_CallMethodExpression o        ; "Method call"                       end
   def label_CaseExpression o              ; "'case' statement"                  end
   def label_CaseOption o                  ; "Case Option"                       end
   def label_RenderStringExpression o      ; "Epp Text"                          end
   def label_RenderExpression o            ; "Epp Interpolated Expression"       end
   def label_RelationshipExpression o      ; "'#{o.operator}' expression"        end
   def label_ResourceBody o                ; "Resource Instance Definition"      end
   def label_ResourceDefaultsExpression o  ; "Resource Defaults Expression"      end
   def label_ResourceExpression o          ; "Resource Statement"                end
   def label_SelectorExpression o          ; "Selector Expression"               end
   def label_SelectorEntry o               ; "Selector Option"                   end
   def label_Integer o                     ; "Integer"                           end
   def label_Fixnum o                      ; "Integer"                           end
   def label_Bignum o                      ; "Integer"                           end
   def label_Float o                       ; "Float"                             end
   def label_String o                      ; "String"                            end
   def label_Regexp o                      ; "Regexp"                            end
   def label_Object o                      ; "Object"                            end
   def label_Hash o                        ; "Hash"                              end
   def label_QualifiedName o               ; "Name"                              end
   def label_QualifiedReference o          ; "Type-Name"                         end
   def label_PAnyType o                    ; "#{Puppet::Pops::Types::TypeCalculator.string(o)}-Type" end
   def label_ReservedWord o                ; "Reserved Word '#{o.word}'"         end
 
   def label_PResourceType o
     if o.title
       "#{Puppet::Pops::Types::TypeCalculator.string(o)} Resource-Reference"
     else
       "#{Puppet::Pops::Types::TypeCalculator.string(o)}-Type"
     end
   end
 
   def label_Class o
     if o <= Puppet::Pops::Types::PAnyType
       simple_name = o.name.split('::').last
       simple_name[1..-5] + "-Type"
     else
       o.name
     end
   end
 end
diff --git a/lib/puppet/pops/validation/checker4_0.rb b/lib/puppet/pops/validation/checker4_0.rb
index 079710d59..8e0c4f93a 100644
--- a/lib/puppet/pops/validation/checker4_0.rb
+++ b/lib/puppet/pops/validation/checker4_0.rb
@@ -1,760 +1,762 @@
 # A Validator validates a model.
 #
 # Validation is performed on each model element in isolation. Each method should validate the model element's state
 # but not validate its referenced/contained elements except to check their validity in their respective role.
 # The intent is to drive the validation with a tree iterator that visits all elements in a model.
 #
 #
 # TODO: Add validation of multiplicities - this is a general validation that can be checked for all
 #       Model objects via their metamodel. (I.e an extra call to multiplicity check in polymorph check).
 #       This is however mostly valuable when validating model to model transformations, and is therefore T.B.D
 #
 class Puppet::Pops::Validation::Checker4_0
   Issues = Puppet::Pops::Issues
   Model = Puppet::Pops::Model
 
   attr_reader :acceptor
   # Initializes the validator with a diagnostics producer. This object must respond to
   # `:will_accept?` and `:accept`.
   #
   def initialize(diagnostics_producer)
     @@check_visitor       ||= Puppet::Pops::Visitor.new(nil, "check", 0, 0)
     @@rvalue_visitor      ||= Puppet::Pops::Visitor.new(nil, "rvalue", 0, 0)
     @@hostname_visitor    ||= Puppet::Pops::Visitor.new(nil, "hostname", 1, 2)
     @@assignment_visitor  ||= Puppet::Pops::Visitor.new(nil, "assign", 0, 1)
     @@query_visitor       ||= Puppet::Pops::Visitor.new(nil, "query", 0, 0)
     @@top_visitor         ||= Puppet::Pops::Visitor.new(nil, "top", 1, 1)
     @@relation_visitor    ||= Puppet::Pops::Visitor.new(nil, "relation", 0, 0)
     @@idem_visitor        ||= Puppet::Pops::Visitor.new(self, "idem", 0, 0)
 
     @acceptor = diagnostics_producer
   end
 
   # Validates the entire model by visiting each model element and calling `check`.
   # The result is collected (or acted on immediately) by the configured diagnostic provider/acceptor
   # given when creating this Checker.
   #
   def validate(model)
     # tree iterate the model, and call check for each element
     check(model)
     model.eAllContents.each {|m| check(m) }
   end
 
   # Performs regular validity check
   def check(o)
     @@check_visitor.visit_this_0(self, o)
   end
 
   # Performs check if this is a vaid hostname expression
   # @param single_feature_name [String, nil] the name of a single valued hostname feature of the value's container. e.g. 'parent'
   def hostname(o, semantic, single_feature_name = nil)
     @@hostname_visitor.visit_this_2(self, o, semantic, single_feature_name)
   end
 
   # Performs check if this is valid as a query
   def query(o)
     @@query_visitor.visit_this_0(self, o)
   end
 
   # Performs check if this is valid as a relationship side
   def relation(o)
     @@relation_visitor.visit_this_0(self, o)
   end
 
   # Performs check if this is valid as a rvalue
   def rvalue(o)
     @@rvalue_visitor.visit_this_0(self, o)
   end
 
   # Performs check if this is valid as a container of a definition (class, define, node)
   def top(o, definition)
     @@top_visitor.visit_this_1(self, o, definition)
   end
 
   # Checks the LHS of an assignment (is it assignable?).
   # If args[0] is true, assignment via index is checked.
   #
   def assign(o, via_index = false)
     @@assignment_visitor.visit_this_1(self, o, via_index)
   end
 
   # Checks if the expression has side effect ('idem' is latin for 'the same', here meaning that the evaluation state
   # is known to be unchanged after the expression has been evaluated). The result is not 100% authoritative for
   # negative answers since analysis of function behavior is not possible.
   # @return [Boolean] true if expression is known to have no effect on evaluation state
   #
   def idem(o)
     @@idem_visitor.visit_this_0(self, o)
   end
 
   # Returns the last expression in a block, or the expression, if that expression is idem
   def ends_with_idem(o)
     if o.is_a?(Puppet::Pops::Model::BlockExpression)
       last = o.statements[-1]
       idem(last) ? last : nil
     else
       idem(o) ? o : nil
     end
   end
 
   #---ASSIGNMENT CHECKS
 
   def assign_VariableExpression(o, via_index)
     varname_string = varname_to_s(o.expr)
     if varname_string =~ Puppet::Pops::Patterns::NUMERIC_VAR_NAME
       acceptor.accept(Issues::ILLEGAL_NUMERIC_ASSIGNMENT, o, :varname => varname_string)
     end
     # Can not assign to something in another namespace (i.e. a '::' in the name is not legal)
     if acceptor.will_accept? Issues::CROSS_SCOPE_ASSIGNMENT
       if varname_string =~ /::/
         acceptor.accept(Issues::CROSS_SCOPE_ASSIGNMENT, o, :name => varname_string)
       end
     end
     # TODO: Could scan for reassignment of the same variable if done earlier in the same container
     #       Or if assigning to a parameter (more work).
     # TODO: Investigate if there are invalid cases for += assignment
   end
 
   def assign_AccessExpression(o, via_index)
     # Are indexed assignments allowed at all ? $x[x] = '...'
     if acceptor.will_accept? Issues::ILLEGAL_INDEXED_ASSIGNMENT
       acceptor.accept(Issues::ILLEGAL_INDEXED_ASSIGNMENT, o)
     else
       # Then the left expression must be assignable-via-index
       assign(o.left_expr, true)
     end
   end
 
   def assign_Object(o, via_index)
     # Can not assign to anything else (differentiate if this is via index or not)
     # i.e. 10 = 'hello' vs. 10['x'] = 'hello' (the root is reported as being in error in both cases)
     #
     acceptor.accept(via_index ? Issues::ILLEGAL_ASSIGNMENT_VIA_INDEX : Issues::ILLEGAL_ASSIGNMENT, o)
   end
 
   #---CHECKS
 
   def check_Object(o)
   end
 
   def check_Factory(o)
     check(o.current)
   end
 
   def check_AccessExpression(o)
     # Only min range is checked, all other checks are RT checks as they depend on the resulting type
     # of the LHS.
     if o.keys.size < 1
       acceptor.accept(Issues::MISSING_INDEX, o)
     end
   end
 
   def check_AssignmentExpression(o)
     case o.operator
     when :'='
       assign(o.left_expr)
       rvalue(o.right_expr)
     when :'+=', :'-='
       acceptor.accept(Issues::APPENDS_DELETES_NO_LONGER_SUPPORTED, o, {:operator => o.operator})
     else
       acceptor.accept(Issues::UNSUPPORTED_OPERATOR, o, {:operator => o.operator})
     end
   end
 
   # Checks that operation with :+> is contained in a ResourceOverride or Collector.
   #
   # Parent of an AttributeOperation can be one of:
   # * CollectExpression
   # * ResourceOverride
   # * ResourceBody (ILLEGAL this is a regular resource expression)
   # * ResourceDefaults (ILLEGAL)
   #
   def check_AttributeOperation(o)
     if o.operator == :'+>'
       # Append operator use is constrained
       parent = o.eContainer
       unless parent.is_a?(Model::CollectExpression) || parent.is_a?(Model::ResourceOverrideExpression)
         acceptor.accept(Issues::ILLEGAL_ATTRIBUTE_APPEND, o, {:name=>o.attribute_name, :parent=>parent})
       end
     end
     rvalue(o.value_expr)
   end
 
   def check_AttributesOperation(o)
     # Append operator use is constrained
     parent = o.eContainer
     parent = parent.eContainer unless parent.nil?
     unless parent.is_a?(Model::ResourceExpression)
       acceptor.accept(Issues::UNSUPPORTED_OPERATOR_IN_CONTEXT, o, :operator=>'* =>')
     end
 
     rvalue(o.expr)
   end
 
   def check_BinaryExpression(o)
     rvalue(o.left_expr)
     rvalue(o.right_expr)
   end
 
   def check_BlockExpression(o)
     o.statements[0..-2].each do |statement|
       if idem(statement)
         acceptor.accept(Issues::IDEM_EXPRESSION_NOT_LAST, statement)
         break # only flag the first
       end
     end
   end
 
   def check_CallNamedFunctionExpression(o)
     case o.functor_expr
     when Puppet::Pops::Model::QualifiedName
       # ok
       nil
     when Puppet::Pops::Model::RenderStringExpression
       # helpful to point out this easy to make Epp error
       acceptor.accept(Issues::ILLEGAL_EPP_PARAMETERS, o)
     else
       acceptor.accept(Issues::ILLEGAL_EXPRESSION, o.functor_expr, {:feature=>'function name', :container => o})
     end
   end
 
   def check_EppExpression(o)
     if o.eContainer.is_a?(Puppet::Pops::Model::LambdaExpression)
       internal_check_no_capture(o.eContainer, o)
     end
   end
 
   def check_MethodCallExpression(o)
     unless o.functor_expr.is_a? Model::QualifiedName
       acceptor.accept(Issues::ILLEGAL_EXPRESSION, o.functor_expr, :feature => 'function name', :container => o)
     end
   end
 
   def check_CaseExpression(o)
     rvalue(o.test)
     # There should only be one LiteralDefault case option value
     # TODO: Implement this check
   end
 
   def check_CaseOption(o)
     o.values.each { |v| rvalue(v) }
   end
 
   def check_CollectExpression(o)
     unless o.type_expr.is_a? Model::QualifiedReference
       acceptor.accept(Issues::ILLEGAL_EXPRESSION, o.type_expr, :feature=> 'type name', :container => o)
     end
 
     # If a collect expression tries to collect exported resources and storeconfigs is not on
     # then it will not work... This was checked in the parser previously. This is a runtime checking
     # thing as opposed to a language thing.
     if acceptor.will_accept?(Issues::RT_NO_STORECONFIGS) && o.query.is_a?(Model::ExportedQuery)
       acceptor.accept(Issues::RT_NO_STORECONFIGS, o)
     end
   end
 
   # Only used for function names, grammar should not be able to produce something faulty, but
   # check anyway if model is created programatically (it will fail in transformation to AST for sure).
   def check_NamedAccessExpression(o)
     name = o.right_expr
     unless name.is_a? Model::QualifiedName
       acceptor.accept(Issues::ILLEGAL_EXPRESSION, name, :feature=> 'function name', :container => o.eContainer)
     end
   end
 
   RESERVED_TYPE_NAMES = {
     'type' => true,
     'any' => true,
     'unit' => true,
     'scalar' => true,
     'boolean' => true,
     'numeric' => true,
     'integer' => true,
     'float' => true,
     'collection' => true,
     'array' => true,
     'hash' => true,
     'tuple' => true,
     'struct' => true,
     'variant' => true,
     'optional' => true,
     'enum' => true,
     'regexp' => true,
     'pattern' => true,
     'runtime' => true,
   }
 
   # for 'class', 'define', and function
   def check_NamedDefinition(o)
     top(o.eContainer, o)
     if o.name !~ Puppet::Pops::Patterns::CLASSREF
       acceptor.accept(Issues::ILLEGAL_DEFINITION_NAME, o, {:name=>o.name})
     end
 
     if RESERVED_TYPE_NAMES[o.name()]
       acceptor.accept(Issues::RESERVED_TYPE_NAME, o, {:name => o.name})
     end
 
     if violator = ends_with_idem(o.body)
       acceptor.accept(Issues::IDEM_NOT_ALLOWED_LAST, violator, {:container => o})
     end
   end
 
   def check_HostClassDefinition(o)
     check_NamedDefinition(o)
     internal_check_no_capture(o)
     internal_check_reserved_params(o)
   end
 
   def check_ResourceTypeDefinition(o)
     check_NamedDefinition(o)
     internal_check_no_capture(o)
     internal_check_reserved_params(o)
   end
 
   def internal_check_capture_last(o)
     accepted_index = o.parameters.size() -1
     o.parameters.each_with_index do |p, index|
       if p.captures_rest && index != accepted_index
         acceptor.accept(Issues::CAPTURES_REST_NOT_LAST, p, {:param_name => p.name})
       end
     end
   end
 
   def internal_check_no_capture(o, container = o)
     o.parameters.each do |p|
       if p.captures_rest
         acceptor.accept(Issues::CAPTURES_REST_NOT_SUPPORTED, p, {:container => container, :param_name => p.name})
       end
     end
   end
 
   RESERVED_PARAMETERS = {
     'name' => true,
     'title' => true,
   }
 
   def internal_check_reserved_params(o)
     o.parameters.each do |p|
       if RESERVED_PARAMETERS[p.name]
         acceptor.accept(Issues::RESERVED_PARAMETER, p, {:container => o, :param_name => p.name})
       end
     end
   end
 
   def check_IfExpression(o)
     rvalue(o.test)
   end
 
   def check_KeyedEntry(o)
     rvalue(o.key)
     rvalue(o.value)
     # In case there are additional things to forbid than non-rvalues
     # acceptor.accept(Issues::ILLEGAL_EXPRESSION, o.key, :feature => 'hash key', :container => o.eContainer)
   end
 
   def check_LambdaExpression(o)
     internal_check_capture_last(o)
   end
 
   def check_LiteralList(o)
     o.values.each {|v| rvalue(v) }
   end
 
   def check_NodeDefinition(o)
     # Check that hostnames are valid hostnames (or regular expressions)
     hostname(o.host_matches, o)
     hostname(o.parent, o, 'parent') unless o.parent.nil?
     top(o.eContainer, o)
     if violator = ends_with_idem(o.body)
       acceptor.accept(Issues::IDEM_NOT_ALLOWED_LAST, violator, {:container => o})
     end
     unless o.parent.nil?
       acceptor.accept(Issues::ILLEGAL_NODE_INHERITANCE, o.parent)
     end
   end
 
   # No checking takes place - all expressions using a QualifiedName need to check. This because the
   # rules are slightly different depending on the container (A variable allows a numeric start, but not
   # other names). This means that (if the lexer/parser so chooses) a QualifiedName
   # can be anything when it represents a Bare Word and evaluates to a String.
   #
   def check_QualifiedName(o)
   end
 
   # Checks that the value is a valid UpperCaseWord (a CLASSREF), and optionally if it contains a hypen.
   # DOH: QualifiedReferences are created with LOWER CASE NAMES at parse time
   def check_QualifiedReference(o)
     # Is this a valid qualified name?
     if o.value !~ Puppet::Pops::Patterns::CLASSREF
       acceptor.accept(Issues::ILLEGAL_CLASSREF, o, {:name=>o.value})
     end
   end
 
   def check_QueryExpression(o)
     query(o.expr) if o.expr  # is optional
   end
 
   def relation_Object(o)
     rvalue(o)
   end
 
   def relation_CollectExpression(o); end
 
   def relation_RelationshipExpression(o); end
 
   def check_Parameter(o)
     if o.name =~ /^(?:0x)?[0-9]+$/
       acceptor.accept(Issues::ILLEGAL_NUMERIC_PARAMETER, o, :name => o.name)
     end
   end
 
   #relationship_side: resource
   #  | resourceref
   #  | collection
   #  | variable
   #  | quotedtext
   #  | selector
   #  | casestatement
   #  | hasharrayaccesses
 
   def check_RelationshipExpression(o)
     relation(o.left_expr)
     relation(o.right_expr)
   end
 
   def check_ResourceExpression(o)
     # The expression for type name cannot be statically checked - this is instead done at runtime
     # to enable better error message of the result of the expression rather than the static instruction.
     # (This can be revised as there are static constructs that are illegal, but require updating many
     # tests that expect the detailed reporting).
   end
 
   def check_ResourceBody(o)
     seenUnfolding = false
     o.operations.each do |ao|
       if ao.is_a?(Puppet::Pops::Model::AttributesOperation)
         if seenUnfolding
           acceptor.accept(Issues::MULTIPLE_ATTRIBUTES_UNFOLD, ao)
         else
           seenUnfolding = true
         end
       end
     end
   end
 
   def check_ResourceDefaultsExpression(o)
     if o.form && o.form != :regular
       acceptor.accept(Issues::NOT_VIRTUALIZEABLE, o)
     end
   end
 
   def check_ResourceOverrideExpression(o)
     if o.form && o.form != :regular
       acceptor.accept(Issues::NOT_VIRTUALIZEABLE, o)
     end
   end
 
   def check_ReservedWord(o)
     acceptor.accept(Issues::RESERVED_WORD, o, :word => o.word)
   end
 
   def check_SelectorExpression(o)
     rvalue(o.left_expr)
   end
 
   def check_SelectorEntry(o)
     rvalue(o.matching_expr)
   end
 
   def check_UnaryExpression(o)
     rvalue(o.expr)
   end
 
   def check_UnlessExpression(o)
     rvalue(o.test)
     # TODO: Unless may not have an else part that is an IfExpression (grammar denies this though)
   end
 
   # Checks that variable is either strictly 0, or a non 0 starting decimal number, or a valid VAR_NAME
   def check_VariableExpression(o)
-    # The expression must be a qualified name
-    if !o.expr.is_a?(Model::QualifiedName)
+    # The expression must be a qualified name or an integer
+    name_expr = o.expr
+    return if name_expr.is_a?(Model::LiteralInteger)
+    if !name_expr.is_a?(Model::QualifiedName)
       acceptor.accept(Issues::ILLEGAL_EXPRESSION, o, :feature => 'name', :container => o)
     else
-      # name must be either a decimal value, or a valid NAME
+      # name must be either a decimal string value, or a valid NAME
       name = o.expr.value
       if name[0,1] =~ /[0-9]/
         unless name =~ Puppet::Pops::Patterns::NUMERIC_VAR_NAME
           acceptor.accept(Issues::ILLEGAL_NUMERIC_VAR_NAME, o, :name => name)
         end
       else
         unless name =~ Puppet::Pops::Patterns::VAR_NAME
           acceptor.accept(Issues::ILLEGAL_VAR_NAME, o, :name => name)
         end
       end
     end
   end
 
   #--- HOSTNAME CHECKS
 
   # Transforms Array of host matching expressions into a (Ruby) array of AST::HostName
   def hostname_Array(o, semantic, single_feature_name)
     if single_feature_name
       acceptor.accept(Issues::ILLEGAL_EXPRESSION, o, {:feature=>single_feature_name, :container=>semantic})
     end
     o.each {|x| hostname(x, semantic, false) }
   end
 
   def hostname_String(o, semantic, single_feature_name)
     # The 3.x checker only checks for illegal characters - if matching /[^-\w.]/ the name is invalid,
     # but this allows pathological names like "a..b......c", "----"
     # TODO: Investigate if more illegal hostnames should be flagged.
     #
     if o =~ Puppet::Pops::Patterns::ILLEGAL_HOSTNAME_CHARS
       acceptor.accept(Issues::ILLEGAL_HOSTNAME_CHARS, semantic, :hostname => o)
     end
   end
 
   def hostname_LiteralValue(o, semantic, single_feature_name)
     hostname_String(o.value.to_s, o, single_feature_name)
   end
 
   def hostname_ConcatenatedString(o, semantic, single_feature_name)
     # Puppet 3.1. only accepts a concatenated string without interpolated expressions
     if the_expr = o.segments.index {|s| s.is_a?(Model::TextExpression) }
       acceptor.accept(Issues::ILLEGAL_HOSTNAME_INTERPOLATION, o.segments[the_expr].expr)
     elsif o.segments.size() != 1
       # corner case, bad model, concatenation of several plain strings
       acceptor.accept(Issues::ILLEGAL_HOSTNAME_INTERPOLATION, o)
     else
       # corner case, may be ok, but lexer may have replaced with plain string, this is
       # here if it does not
       hostname_String(o.segments[0], o.segments[0], false)
     end
   end
 
   def hostname_QualifiedName(o, semantic, single_feature_name)
     hostname_String(o.value.to_s, o, single_feature_name)
   end
 
   def hostname_QualifiedReference(o, semantic, single_feature_name)
     hostname_String(o.value.to_s, o, single_feature_name)
   end
 
   def hostname_LiteralNumber(o, semantic, single_feature_name)
     # always ok
   end
 
   def hostname_LiteralDefault(o, semantic, single_feature_name)
     # always ok
   end
 
   def hostname_LiteralRegularExpression(o, semantic, single_feature_name)
     # always ok
   end
 
   def hostname_Object(o, semantic, single_feature_name)
     acceptor.accept(Issues::ILLEGAL_EXPRESSION, o, {:feature=> single_feature_name || 'hostname', :container=>semantic})
   end
 
   #---QUERY CHECKS
 
   # Anything not explicitly allowed is flagged as error.
   def query_Object(o)
     acceptor.accept(Issues::ILLEGAL_QUERY_EXPRESSION, o)
   end
 
   # Puppet AST only allows == and !=
   #
   def query_ComparisonExpression(o)
     acceptor.accept(Issues::ILLEGAL_QUERY_EXPRESSION, o) unless [:'==', :'!='].include? o.operator
   end
 
   # Allows AND, OR, and checks if left/right are allowed in query.
   def query_BooleanExpression(o)
     query o.left_expr
     query o.right_expr
   end
 
   def query_ParenthesizedExpression(o)
     query(o.expr)
   end
 
   def query_VariableExpression(o); end
 
   def query_QualifiedName(o); end
 
   def query_LiteralNumber(o); end
 
   def query_LiteralString(o); end
 
   def query_LiteralBoolean(o); end
 
   #---RVALUE CHECKS
 
   # By default, all expressions are reported as being rvalues
   # Implement specific rvalue checks for those that are not.
   #
   def rvalue_Expression(o); end
 
   def rvalue_CollectExpression(o)         ; acceptor.accept(Issues::NOT_RVALUE, o) ; end
 
   def rvalue_Definition(o)                ; acceptor.accept(Issues::NOT_RVALUE, o) ; end
 
   def rvalue_NodeDefinition(o)            ; acceptor.accept(Issues::NOT_RVALUE, o) ; end
 
   def rvalue_UnaryExpression(o)           ; rvalue o.expr                 ; end
 
   #---TOP CHECK
 
   def top_NilClass(o, definition)
     # ok, reached the top, no more parents
   end
 
   def top_Object(o, definition)
     # fail, reached a container that is not top level
     acceptor.accept(Issues::NOT_TOP_LEVEL, definition)
   end
 
   def top_BlockExpression(o, definition)
     # ok, if this is a block representing the body of a class, or is top level
     top o.eContainer, definition
   end
 
   def top_HostClassDefinition(o, definition)
     # ok, stop scanning parents
   end
 
   def top_Program(o, definition)
     # ok
   end
 
   # A LambdaExpression is a BlockExpression, and this method is needed to prevent the polymorph method for BlockExpression
   # to accept a lambda.
   # A lambda can not iteratively create classes, nodes or defines as the lambda does not have a closure.
   #
   def top_LambdaExpression(o, definition)
     # fail, stop scanning parents
     acceptor.accept(Issues::NOT_TOP_LEVEL, definition)
   end
 
   #--IDEM CHECK
   def idem_Object(o)
     false
   end
 
   def idem_Nop(o)
     true
   end
 
   def idem_NilClass(o)
     true
   end
 
   def idem_Literal(o)
     true
   end
 
   def idem_LiteralList(o)
     true
   end
 
   def idem_LiteralHash(o)
     true
   end
 
   def idem_Factory(o)
     idem(o.current)
   end
 
   def idem_AccessExpression(o)
     true
   end
 
   def idem_BinaryExpression(o)
     true
   end
 
   def idem_RelationshipExpression(o)
     # Always side effect
     false
   end
 
   def idem_AssignmentExpression(o)
     # Always side effect
     false
   end
 
   # Handles UnaryMinusExpression, NotExpression, VariableExpression
   def idem_UnaryExpression(o)
     true
   end
 
   # Allow (no-effect parentheses) to be used around a productive expression
   def idem_ParenthesizedExpression(o)
     idem(o.expr)
   end
 
   def idem_RenderExpression(o)
     false
   end
 
   def idem_RenderStringExpression(o)
     false
   end
 
   def idem_BlockExpression(o)
     # productive if there is at least one productive expression
     ! o.statements.any? {|expr| !idem(expr) }
   end
 
   # Returns true even though there may be interpolated expressions that have side effect.
   # Report as idem anyway, as it is very bad design to evaluate an interpolated string for its
   # side effect only.
   def idem_ConcatenatedString(o)
     true
   end
 
   # Heredoc is just a string, but may contain interpolated string (which may have side effects).
   # This is still bad design and should be reported as idem.
   def idem_HeredocExpression(o)
     true
   end
 
   # May technically have side effects inside the Selector, but this is bad design - treat as idem
   def idem_SelectorExpression(o)
     true
   end
 
   def idem_IfExpression(o)
     [o.test, o.then_expr, o.else_expr].all? {|e| idem(e) }
   end
 
   # Case expression is idem, if test, and all options are idem
   def idem_CaseExpression(o)
     return false if !idem(o.test)
     ! o.options.any? {|opt| !idem(opt) }
   end
 
   # An option is idem if values and the then_expression are idem
   def idem_CaseOption(o)
     return false if o.values.any? { |value| !idem(value) }
     idem(o.then_expr)
   end
 
   #--- NON POLYMORPH, NON CHECKING CODE
 
   # Produces string part of something named, or nil if not a QualifiedName or QualifiedReference
   #
   def varname_to_s(o)
     case o
     when Model::QualifiedName
       o.value
     when Model::QualifiedReference
       o.value
     else
       nil
     end
   end
 end
diff --git a/spec/unit/pops/evaluator/evaluating_parser_spec.rb b/spec/unit/pops/evaluator/evaluating_parser_spec.rb
index e22e1342f..37dd2e8cb 100644
--- a/spec/unit/pops/evaluator/evaluating_parser_spec.rb
+++ b/spec/unit/pops/evaluator/evaluating_parser_spec.rb
@@ -1,1337 +1,1357 @@
 require 'spec_helper'
 
 require 'puppet/pops'
 require 'puppet/pops/evaluator/evaluator_impl'
 require 'puppet/loaders'
 require 'puppet_spec/pops'
 require 'puppet_spec/scope'
 require 'puppet/parser/e4_parser_adapter'
 
 
 # relative to this spec file (./) does not work as this file is loaded by rspec
 #require File.join(File.dirname(__FILE__), '/evaluator_rspec_helper')
 
 describe 'Puppet::Pops::Evaluator::EvaluatorImpl' do
   include PuppetSpec::Pops
   include PuppetSpec::Scope
   before(:each) do
     Puppet[:strict_variables] = true
 
     # These must be set since the 3x logic switches some behaviors on these even if the tests explicitly
     # use the 4x parser and evaluator.
     #
     Puppet[:parser] = 'future'
 
     # Puppetx cannot be loaded until the correct parser has been set (injector is turned off otherwise)
     require 'puppetx'
 
     # Tests needs a known configuration of node/scope/compiler since it parses and evaluates
     # snippets as the compiler will evaluate them, butwithout the overhead of compiling a complete
     # catalog for each tested expression.
     #
     @parser  = Puppet::Pops::Parser::EvaluatingParser.new
     @node = Puppet::Node.new('node.example.com')
     @node.environment = Puppet::Node::Environment.create(:testing, [])
     @compiler = Puppet::Parser::Compiler.new(@node)
     @scope = Puppet::Parser::Scope.new(@compiler)
     @scope.source = Puppet::Resource::Type.new(:node, 'node.example.com')
     @scope.parent = @compiler.topscope
   end
 
   let(:parser) {  @parser }
   let(:scope) { @scope }
   types = Puppet::Pops::Types::TypeFactory
 
   context "When evaluator evaluates literals" do
     {
       "1"             => 1,
       "010"           => 8,
       "0x10"          => 16,
       "3.14"          => 3.14,
       "0.314e1"       => 3.14,
       "31.4e-1"       => 3.14,
       "'1'"           => '1',
       "'banana'"      => 'banana',
       '"banana"'      => 'banana',
       "banana"        => 'banana',
       "banana::split" => 'banana::split',
       "false"         => false,
       "true"          => true,
       "Array"         => types.array_of_data(),
       "/.*/"          => /.*/
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
   end
 
   context "When the evaluator evaluates Lists and Hashes" do
     {
       "[]"                                              => [],
       "[1,2,3]"                                         => [1,2,3],
       "[1,[2.0, 2.1, [2.2]],[3.0, 3.1]]"                => [1,[2.0, 2.1, [2.2]],[3.0, 3.1]],
       "[2 + 2]"                                         => [4],
       "[1,2,3] == [1,2,3]"                              => true,
       "[1,2,3] != [2,3,4]"                              => true,
       "[1,2,3] == [2,2,3]"                              => false,
       "[1,2,3] != [1,2,3]"                              => false,
       "[1,2,3][2]"                                      => 3,
       "[1,2,3] + [4,5]"                                 => [1,2,3,4,5],
       "[1,2,3] + [[4,5]]"                               => [1,2,3,[4,5]],
       "[1,2,3] + 4"                                     => [1,2,3,4],
       "[1,2,3] << [4,5]"                                => [1,2,3,[4,5]],
       "[1,2,3] << {'a' => 1, 'b'=>2}"                   => [1,2,3,{'a' => 1, 'b'=>2}],
       "[1,2,3] << 4"                                    => [1,2,3,4],
       "[1,2,3,4] - [2,3]"                               => [1,4],
       "[1,2,3,4] - [2,5]"                               => [1,3,4],
       "[1,2,3,4] - 2"                                   => [1,3,4],
       "[1,2,3,[2],4] - 2"                               => [1,3,[2],4],
       "[1,2,3,[2,3],4] - [[2,3]]"                       => [1,2,3,4],
       "[1,2,3,3,2,4,2,3] - [2,3]"                       => [1,4],
       "[1,2,3,['a',1],['b',2]] - {'a' => 1, 'b'=>2}"    => [1,2,3],
       "[1,2,3,{'a'=>1,'b'=>2}] - [{'a' => 1, 'b'=>2}]"  => [1,2,3],
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     {
       "[1,2,3] + {'a' => 1, 'b'=>2}"                    => [1,2,3,['a',1],['b',2]],
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           # This test must be done with match_array since the order of the hash
           # is undefined and Ruby 1.8.7 and 1.9.3 produce different results.
           expect(parser.evaluate_string(scope, source, __FILE__)).to match_array(result)
         end
       end
 
     {
       "[1,2,3][a]" => :error,
     }.each do |source, result|
         it "should parse and raise error for '#{source}'" do
           expect { parser.evaluate_string(scope, source, __FILE__) }.to raise_error(Puppet::ParseError)
         end
       end
 
     {
       "{}"                                       => {},
       "{'a'=>1,'b'=>2}"                          => {'a'=>1,'b'=>2},
       "{'a'=>1,'b'=>{'x'=>2.1,'y'=>2.2}}"        => {'a'=>1,'b'=>{'x'=>2.1,'y'=>2.2}},
       "{'a'=> 2 + 2}"                            => {'a'=> 4},
       "{'a'=> 1, 'b'=>2} == {'a'=> 1, 'b'=>2}"   => true,
       "{'a'=> 1, 'b'=>2} != {'x'=> 1, 'b'=>2}"   => true,
       "{'a'=> 1, 'b'=>2} == {'a'=> 2, 'b'=>3}"   => false,
       "{'a'=> 1, 'b'=>2} != {'a'=> 1, 'b'=>2}"   => false,
       "{a => 1, b => 2}[b]"                      => 2,
       "{2+2 => sum, b => 2}[4]"                  => 'sum',
       "{'a'=>1, 'b'=>2} + {'c'=>3}"              => {'a'=>1,'b'=>2,'c'=>3},
       "{'a'=>1, 'b'=>2} + {'b'=>3}"              => {'a'=>1,'b'=>3},
       "{'a'=>1, 'b'=>2} + ['c', 3, 'b', 3]"      => {'a'=>1,'b'=>3, 'c'=>3},
       "{'a'=>1, 'b'=>2} + [['c', 3], ['b', 3]]"  => {'a'=>1,'b'=>3, 'c'=>3},
       "{'a'=>1, 'b'=>2} - {'b' => 3}"            => {'a'=>1},
       "{'a'=>1, 'b'=>2, 'c'=>3} - ['b', 'c']"    => {'a'=>1},
       "{'a'=>1, 'b'=>2, 'c'=>3} - 'c'"           => {'a'=>1, 'b'=>2},
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     {
       "{'a' => 1, 'b'=>2} << 1" => :error,
     }.each do |source, result|
         it "should parse and raise error for '#{source}'" do
           expect { parser.evaluate_string(scope, source, __FILE__) }.to raise_error(Puppet::ParseError)
         end
       end
   end
 
   context "When the evaluator perform comparisons" do
     {
       "'a' == 'a'"     => true,
       "'a' == 'b'"     => false,
       "'a' != 'a'"     => false,
       "'a' != 'b'"     => true,
       "'a' < 'b' "     => true,
       "'a' < 'a' "     => false,
       "'b' < 'a' "     => false,
       "'a' <= 'b'"     => true,
       "'a' <= 'a'"     => true,
       "'b' <= 'a'"     => false,
       "'a' > 'b' "     => false,
       "'a' > 'a' "     => false,
       "'b' > 'a' "     => true,
       "'a' >= 'b'"     => false,
       "'a' >= 'a'"     => true,
       "'b' >= 'a'"     => true,
       "'a' == 'A'"     => true,
       "'a' != 'A'"     => false,
       "'a' >  'A'"     => false,
       "'a' >= 'A'"     => true,
       "'A' <  'a'"     => false,
       "'A' <= 'a'"     => true,
       "1 == 1"         => true,
       "1 == 2"         => false,
       "1 != 1"         => false,
       "1 != 2"         => true,
       "1 < 2 "         => true,
       "1 < 1 "         => false,
       "2 < 1 "         => false,
       "1 <= 2"         => true,
       "1 <= 1"         => true,
       "2 <= 1"         => false,
       "1 > 2 "         => false,
       "1 > 1 "         => false,
       "2 > 1 "         => true,
       "1 >= 2"         => false,
       "1 >= 1"         => true,
       "2 >= 1"         => true,
       "1 == 1.0 "      => true,
       "1 < 1.1  "      => true,
       "1.0 == 1 "      => true,
       "1.0 < 2  "      => true,
       "'1.0' < 'a'"    => true,
       "'1.0' < '' "    => false,
       "'1.0' < ' '"    => false,
       "'a' > '1.0'"    => true,
       "/.*/ == /.*/ "  => true,
       "/.*/ != /a.*/"  => true,
       "true  == true " => true,
       "false == false" => true,
       "true == false"  => false,
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
    {
      "a > 1" => /String > Integer/,
      "a >= 1" => /String >= Integer/,
      "a < 1" => /String < Integer/,
      "a <= 1" => /String <= Integer/,
      "1 > a" => /Integer > String/,
      "1 >= a" => /Integer >= String/,
      "1 < a" => /Integer < String/,
      "1 <= a" => /Integer <= String/,
    }.each do | source, error|
      it "should not allow comparison of String and Number '#{source}'" do
        expect { parser.evaluate_string(scope, source, __FILE__)}.to raise_error(error)
      end
    end
 
    {
       "'a' =~ /.*/"                     => true,
       "'a' =~ '.*'"                     => true,
       "/.*/ != /a.*/"                   => true,
       "'a' !~ /b.*/"                    => true,
       "'a' !~ 'b.*'"                    => true,
       '$x = a; a =~ "$x.*"'             => true,
       "a =~ Pattern['a.*']"             => true,
       "a =~ Regexp['a.*']"              => false, # String is not subtype of Regexp. PUP-957
       "$x = /a.*/ a =~ $x"              => true,
       "$x = Pattern['a.*'] a =~ $x"     => true,
       "1 =~ Integer"                    => true,
       "1 !~ Integer"                    => false,
       "[1,2,3] =~ Array[Integer[1,10]]" => true,
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     {
       "666 =~ /6/"    => :error,
       "[a] =~ /a/"    => :error,
       "{a=>1} =~ /a/" => :error,
        "/a/ =~ /a/"    => :error,
       "Array =~ /A/"  => :error,
     }.each do |source, result|
         it "should parse and raise error for '#{source}'" do
           expect { parser.evaluate_string(scope, source, __FILE__) }.to raise_error(Puppet::ParseError)
         end
       end
 
     {
       "1 in [1,2,3]"                  => true,
       "4 in [1,2,3]"                  => false,
       "a in {x=>1, a=>2}"             => true,
       "z in {x=>1, a=>2}"             => false,
       "ana in bananas"                => true,
       "xxx in bananas"                => false,
       "/ana/ in bananas"              => true,
       "/xxx/ in bananas"              => false,
       "ANA in bananas"                => false, # ANA is a type, not a String
       "String[1] in bananas"          => false, # Philosophically true though :-)
       "'ANA' in bananas"              => true,
       "ana in 'BANANAS'"              => true,
       "/ana/ in 'BANANAS'"            => false,
       "/ANA/ in 'BANANAS'"            => true,
       "xxx in 'BANANAS'"              => false,
       "[2,3] in [1,[2,3],4]"          => true,
       "[2,4] in [1,[2,3],4]"          => false,
       "[a,b] in ['A',['A','B'],'C']"  => true,
       "[x,y] in ['A',['A','B'],'C']"  => false,
       "a in {a=>1}"                   => true,
       "x in {a=>1}"                   => false,
       "'A' in {a=>1}"                 => true,
       "'X' in {a=>1}"                 => false,
       "a in {'A'=>1}"                 => true,
       "x in {'A'=>1}"                 => false,
       "/xxx/ in {'aaaxxxbbb'=>1}"     => true,
       "/yyy/ in {'aaaxxxbbb'=>1}"     => false,
       "15 in [1, 0xf]"                => true,
       "15 in [1, '0xf']"              => false,
       "'15' in [1, 0xf]"              => false,
       "15 in [1, 115]"                => false,
       "1 in [11, '111']"              => false,
       "'1' in [11, '111']"            => false,
       "Array[Integer] in [2, 3]"      => false,
       "Array[Integer] in [2, [3, 4]]" => true,
       "Array[Integer] in [2, [a, 4]]" => false,
       "Integer in { 2 =>'a'}"         => true,
       "Integer[5,10] in [1,5,3]"      => true,
       "Integer[5,10] in [1,2,3]"      => false,
       "Integer in {'a'=>'a'}"         => false,
       "Integer in {'a'=>1}"           => false,
     }.each do |source, result|
       it "should parse and evaluate the expression '#{source}' to #{result}" do
         parser.evaluate_string(scope, source, __FILE__).should == result
       end
     end
 
     {
       "if /(ana)/ in bananas {$1}" => 'ana',
       "if /(xyz)/ in bananas {$1} else {$1}" => nil,
       "$a = bananas =~ /(ana)/; $b = /(xyz)/ in bananas; $1" => 'ana',
       "$a = xyz =~ /(xyz)/; $b = /(ana)/ in bananas; $1" => 'ana',
       "if /p/ in [pineapple, bananas] {$0}" => 'p',
       "if /b/ in [pineapple, bananas] {$0}" => 'b',
     }.each do |source, result|
       it "sets match variables for a regexp search using in such that '#{source}' produces '#{result}'" do
           parser.evaluate_string(scope, source, __FILE__).should == result
       end
     end
 
     {
       'Any'  => ['Data', 'Scalar', 'Numeric', 'Integer', 'Float', 'Boolean', 'String', 'Pattern', 'Collection',
                     'Array', 'Hash', 'CatalogEntry', 'Resource', 'Class', 'Undef', 'File', 'NotYetKnownResourceType'],
 
       # Note, Data > Collection is false (so not included)
       'Data'    => ['Scalar', 'Numeric', 'Integer', 'Float', 'Boolean', 'String', 'Pattern', 'Array', 'Hash',],
       'Scalar' => ['Numeric', 'Integer', 'Float', 'Boolean', 'String', 'Pattern'],
       'Numeric' => ['Integer', 'Float'],
       'CatalogEntry' => ['Class', 'Resource', 'File', 'NotYetKnownResourceType'],
       'Integer[1,10]' => ['Integer[2,3]'],
     }.each do |general, specials|
       specials.each do |special |
         it "should compute that #{general} > #{special}" do
           parser.evaluate_string(scope, "#{general} > #{special}", __FILE__).should == true
         end
         it "should compute that  #{special} < #{general}" do
           parser.evaluate_string(scope, "#{special} < #{general}", __FILE__).should == true
         end
         it "should compute that #{general} != #{special}" do
           parser.evaluate_string(scope, "#{special} != #{general}", __FILE__).should == true
         end
       end
     end
 
     {
       'Integer[1,10] > Integer[2,3]'   => true,
       'Integer[1,10] == Integer[2,3]'  => false,
       'Integer[1,10] > Integer[0,5]'   => false,
       'Integer[1,10] > Integer[1,10]'  => false,
       'Integer[1,10] >= Integer[1,10]' => true,
       'Integer[1,10] == Integer[1,10]' => true,
     }.each do |source, result|
         it "should parse and evaluate the integer range comparison expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
   end
 
   context "When the evaluator performs arithmetic" do
     context "on Integers" do
       {  "2+2"    => 4,
          "2 + 2"  => 4,
          "7 - 3"  => 4,
          "6 * 3"  => 18,
          "6 / 3"  => 2,
          "6 % 3"  => 0,
          "10 % 3" =>  1,
          "-(6/3)" => -2,
          "-6/3  " => -2,
          "8 >> 1" => 4,
          "8 << 1" => 16,
       }.each do |source, result|
           it "should parse and evaluate the expression '#{source}' to #{result}" do
             parser.evaluate_string(scope, source, __FILE__).should == result
           end
         end
 
     context "on Floats" do
       {
         "2.2 + 2.2"  => 4.4,
         "7.7 - 3.3"  => 4.4,
         "6.1 * 3.1"  => 18.91,
         "6.6 / 3.3"  => 2.0,
         "-(6.0/3.0)" => -2.0,
         "-6.0/3.0 "  => -2.0,
       }.each do |source, result|
           it "should parse and evaluate the expression '#{source}' to #{result}" do
             parser.evaluate_string(scope, source, __FILE__).should == result
           end
         end
 
       {
         "3.14 << 2" => :error,
         "3.14 >> 2" => :error,
         "6.6 % 3.3"  => 0.0,
         "10.0 % 3.0" =>  1.0,
       }.each do |source, result|
           it "should parse and raise error for '#{source}'" do
             expect { parser.evaluate_string(scope, source, __FILE__) }.to raise_error(Puppet::ParseError)
           end
         end
     end
 
     context "on strings requiring boxing to Numeric" do
       {
         "'2' + '2'"       => 4,
         "'-2' + '2'"      => 0,
         "'- 2' + '2'"     => 0,
         '"-\t 2" + "2"'   => 0,
         "'+2' + '2'"      => 4,
         "'+ 2' + '2'"     => 4,
         "'2.2' + '2.2'"   => 4.4,
         "'-2.2' + '2.2'"  => 0.0,
         "'0xF7' + '010'"  => 0xFF,
         "'0xF7' + '0x8'"  => 0xFF,
         "'0367' + '010'"  => 0xFF,
         "'012.3' + '010'" => 20.3,
         "'-0x2' + '0x4'"  => 2,
         "'+0x2' + '0x4'"  => 6,
         "'-02' + '04'"    => 2,
         "'+02' + '04'"    => 6,
       }.each do |source, result|
           it "should parse and evaluate the expression '#{source}' to #{result}" do
             parser.evaluate_string(scope, source, __FILE__).should == result
           end
         end
 
       {
         "'0888' + '010'"   => :error,
         "'0xWTF' + '010'"  => :error,
         "'0x12.3' + '010'" => :error,
         "'0x12.3' + '010'" => :error,
         '"-\n 2" + "2"'    => :error,
         '"-\v 2" + "2"'    => :error,
         '"-2\n" + "2"'     => :error,
         '"-2\n " + "2"'    => :error,
       }.each do |source, result|
           it "should parse and raise error for '#{source}'" do
             expect { parser.evaluate_string(scope, source, __FILE__) }.to raise_error(Puppet::ParseError)
           end
         end
       end
     end
   end # arithmetic
 
   context "When the evaluator evaluates assignment" do
     {
       "$a = 5"                     => 5,
       "$a = 5; $a"                 => 5,
       "$a = 5; $b = 6; $a"         => 5,
       "$a = $b = 5; $a == $b"      => true,
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     {
       "[a,b,c] = [1,2,3]"               => /attempt to assign to 'an Array Expression'/,
       "[a,b,c] = {b=>2,c=>3,a=>1}"      => /attempt to assign to 'an Array Expression'/,
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to error with #{result}" do
           expect { parser.evaluate_string(scope, source, __FILE__)}.to raise_error(Puppet::ParseError, result)
         end
       end
   end
 
   context "When the evaluator evaluates conditionals" do
     {
       "if true {5}"                     => 5,
       "if false {5}"                    => nil,
       "if false {2} else {5}"           => 5,
       "if false {2} elsif true {5}"     => 5,
       "if false {2} elsif false {5}"    => nil,
       "unless false {5}"                => 5,
       "unless true {5}"                 => nil,
       "unless true {2} else {5}"        => 5,
       "$a = if true {5} $a"                     => 5,
       "$a = if false {5} $a"                    => nil,
       "$a = if false {2} else {5} $a"           => 5,
       "$a = if false {2} elsif true {5} $a"     => 5,
       "$a = if false {2} elsif false {5} $a"    => nil,
       "$a = unless false {5} $a"                => 5,
       "$a = unless true {5} $a"                 => nil,
       "$a = unless true {2} else {5} $a"        => 5,
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     {
       "case 1 { 1 : { yes } }"                               => 'yes',
       "case 2 { 1,2,3 : { yes} }"                            => 'yes',
       "case 2 { 1,3 : { no } 2: { yes} }"                    => 'yes',
       "case 2 { 1,3 : { no } 5: { no } default: { yes }}"    => 'yes',
       "case 2 { 1,3 : { no } 5: { no } }"                    => nil,
       "case 'banana' { 1,3 : { no } /.*ana.*/: { yes } }"    => 'yes',
       "case 'banana' { /.*(ana).*/: { $1 } }"                => 'ana',
       "case [1] { Array : { yes } }"                         => 'yes',
       "case [1] {
          Array[String] : { no }
          Array[Integer]: { yes }
       }"                                                     => 'yes',
       "case 1 {
          Integer : { yes }
          Type[Integer] : { no } }"                           => 'yes',
       "case Integer {
          Integer : { no }
          Type[Integer] : { yes } }"                          => 'yes',
       # supports unfold
       "case ringo {
          *[paul, john, ringo, george] : { 'beatle' } }"       => 'beatle',
 
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     {
       "2 ? { 1 => no, 2 => yes}"                          => 'yes',
       "3 ? { 1 => no, 2 => no, default => yes }"          => 'yes',
       "3 ? { 1 => no, default => yes, 3 => no }"          => 'no',
       "3 ? { 1 => no, 3 => no, default => yes }"          => 'no',
       "4 ? { 1 => no, default => yes, 3 => no }"          => 'yes',
       "4 ? { 1 => no, 3 => no, default => yes }"          => 'yes',
       "'banana' ? { /.*(ana).*/  => $1 }"                 => 'ana',
       "[2] ? { Array[String] => yes, Array => yes}"       => 'yes',
       "ringo ? *[paul, john, ringo, george] => 'beatle'"  => 'beatle',
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     it 'fails if a selector does not match' do
       expect{parser.evaluate_string(scope, "2 ? 3 => 4")}.to raise_error(/No matching entry for selector parameter with value '2'/)
     end
   end
 
   context "When evaluator evaluated unfold" do
     {
       "*[1,2,3]"             => [1,2,3],
       "*1"                   => [1],
       "*'a'"                 => ['a']
     }.each do |source, result|
       it "should parse and evaluate the expression '#{source}' to #{result}" do
         parser.evaluate_string(scope, source, __FILE__).should == result
       end
     end
 
     it "should parse and evaluate the expression '*{a=>10, b=>20} to [['a',10],['b',20]]" do
       result = parser.evaluate_string(scope, '*{a=>10, b=>20}', __FILE__)
       expect(result).to include(['a', 10])
       expect(result).to include(['b', 20])
     end
 
   end
 
   context "When evaluator performs [] operations" do
     {
       "[1,2,3][0]"      => 1,
       "[1,2,3][2]"      => 3,
       "[1,2,3][3]"      => nil,
       "[1,2,3][-1]"     => 3,
       "[1,2,3][-2]"     => 2,
       "[1,2,3][-4]"     => nil,
       "[1,2,3,4][0,2]"  => [1,2],
       "[1,2,3,4][1,3]"  => [2,3,4],
       "[1,2,3,4][-2,2]"  => [3,4],
       "[1,2,3,4][-3,2]"  => [2,3],
       "[1,2,3,4][3,5]"   => [4],
       "[1,2,3,4][5,2]"   => [],
       "[1,2,3,4][0,-1]"  => [1,2,3,4],
       "[1,2,3,4][0,-2]"  => [1,2,3],
       "[1,2,3,4][0,-4]"  => [1],
       "[1,2,3,4][0,-5]"  => [],
       "[1,2,3,4][-5,2]"  => [1],
       "[1,2,3,4][-5,-3]" => [1,2],
       "[1,2,3,4][-6,-3]" => [1,2],
       "[1,2,3,4][2,-3]"  => [],
       "[1,*[2,3],4]"     => [1,2,3,4],
       "[1,*[2,3],4][1]"  => 2,
     }.each do |source, result|
       it "should parse and evaluate the expression '#{source}' to #{result}" do
         parser.evaluate_string(scope, source, __FILE__).should == result
       end
     end
 
     {
       "{a=>1, b=>2, c=>3}[a]"                => 1,
       "{a=>1, b=>2, c=>3}[c]"                => 3,
       "{a=>1, b=>2, c=>3}[x]"                => nil,
       "{a=>1, b=>2, c=>3}[c,b]"              => [3,2],
       "{a=>1, b=>2, c=>3}[a,b,c]"            => [1,2,3],
       "{a=>{b=>{c=>'it works'}}}[a][b][c]"   => 'it works',
       "$a = {undef => 10} $a[free_lunch]"     => nil,
       "$a = {undef => 10} $a[undef]"          => 10,
       "$a = {undef => 10} $a[$a[free_lunch]]" => 10,
       "$a = {} $a[free_lunch] == undef"       => true,
     }.each do |source, result|
       it "should parse and evaluate the expression '#{source}' to #{result}" do
         parser.evaluate_string(scope, source, __FILE__).should == result
       end
     end
 
     {
       "'abc'[0]"      => 'a',
       "'abc'[2]"      => 'c',
       "'abc'[-1]"     => 'c',
       "'abc'[-2]"     => 'b',
       "'abc'[-3]"     => 'a',
       "'abc'[-4]"     => '',
       "'abc'[3]"      => '',
       "abc[0]"        => 'a',
       "abc[2]"        => 'c',
       "abc[-1]"       => 'c',
       "abc[-2]"       => 'b',
       "abc[-3]"       => 'a',
       "abc[-4]"       => '',
       "abc[3]"        => '',
       "'abcd'[0,2]"   => 'ab',
       "'abcd'[1,3]"   => 'bcd',
       "'abcd'[-2,2]"  => 'cd',
       "'abcd'[-3,2]"  => 'bc',
       "'abcd'[3,5]"   => 'd',
       "'abcd'[5,2]"   => '',
       "'abcd'[0,-1]"  => 'abcd',
       "'abcd'[0,-2]"  => 'abc',
       "'abcd'[0,-4]"  => 'a',
       "'abcd'[0,-5]"  => '',
       "'abcd'[-5,2]"  => 'a',
       "'abcd'[-5,-3]" => 'ab',
       "'abcd'[-6,-3]" => 'ab',
       "'abcd'[2,-3]"  => '',
    }.each do |source, result|
       it "should parse and evaluate the expression '#{source}' to #{result}" do
         parser.evaluate_string(scope, source, __FILE__).should == result
       end
     end
 
     # Type operations (full set tested by tests covering type calculator)
     {
       "Array[Integer]"                  => types.array_of(types.integer),
       "Array[Integer,1]"                => types.constrain_size(types.array_of(types.integer),1, :default),
       "Array[Integer,1,2]"              => types.constrain_size(types.array_of(types.integer),1, 2),
       "Array[Integer,Integer[1,2]]"     => types.constrain_size(types.array_of(types.integer),1, 2),
       "Array[Integer,Integer[1]]"       => types.constrain_size(types.array_of(types.integer),1, :default),
       "Hash[Integer,Integer]"           => types.hash_of(types.integer, types.integer),
       "Hash[Integer,Integer,1]"         => types.constrain_size(types.hash_of(types.integer, types.integer),1, :default),
       "Hash[Integer,Integer,1,2]"       => types.constrain_size(types.hash_of(types.integer, types.integer),1, 2),
       "Hash[Integer,Integer,Integer[1,2]]" => types.constrain_size(types.hash_of(types.integer, types.integer),1, 2),
       "Hash[Integer,Integer,Integer[1]]"   => types.constrain_size(types.hash_of(types.integer, types.integer),1, :default),
       "Resource[File]"                  => types.resource('File'),
       "Resource['File']"                => types.resource(types.resource('File')),
       "File[foo]"                       => types.resource('file', 'foo'),
       "File[foo, bar]"                  => [types.resource('file', 'foo'), types.resource('file', 'bar')],
       "Pattern[a, /b/, Pattern[c], Regexp[d]]"  => types.pattern('a', 'b', 'c', 'd'),
       "String[1,2]"                     => types.constrain_size(types.string,1, 2),
       "String[Integer[1,2]]"            => types.constrain_size(types.string,1, 2),
       "String[Integer[1]]"              => types.constrain_size(types.string,1, :default),
     }.each do |source, result|
       it "should parse and evaluate the expression '#{source}' to #{result}" do
         parser.evaluate_string(scope, source, __FILE__).should == result
       end
     end
 
     # LHS where [] not supported, and missing key(s)
     {
       "Array[]"                    => :error,
       "'abc'[]"                    => :error,
       "Resource[]"                 => :error,
       "File[]"                     => :error,
       "String[]"                   => :error,
       "1[]"                        => :error,
       "3.14[]"                     => :error,
       "/.*/[]"                     => :error,
       "$a=[1] $a[]"                => :error,
     }.each do |source, result|
       it "should parse and evaluate the expression '#{source}' to #{result}" do
         expect { parser.evaluate_string(scope, source, __FILE__)}.to raise_error(/Syntax error/)
       end
     end
 
     # Errors when wrong number/type of keys are used
     {
       "Array[0]"                    => 'Array-Type[] arguments must be types. Got Fixnum',
       "Hash[0]"                     => 'Hash-Type[] arguments must be types. Got Fixnum',
       "Hash[Integer, 0]"            => 'Hash-Type[] arguments must be types. Got Fixnum',
       "Array[Integer,1,2,3]"        => 'Array-Type[] accepts 1 to 3 arguments. Got 4',
       "Array[Integer,String]"       => "A Type's size constraint arguments must be a single Integer type, or 1-2 integers (or default). Got a String-Type",
       "Hash[Integer,String, 1,2,3]" => 'Hash-Type[] accepts 2 to 4 arguments. Got 5',
       "'abc'[x]"                    => "The value 'x' cannot be converted to Numeric",
       "'abc'[1.0]"                  => "A String[] cannot use Float where Integer is expected",
       "'abc'[1,2,3]"                => "String supports [] with one or two arguments. Got 3",
       "Resource[0]"                 => 'First argument to Resource[] must be a resource type or a String. Got Integer',
       "Resource[a, 0]"              => 'Error creating type specialization of a Resource-Type, Cannot use Integer where a resource title String is expected',
       "File[0]"                     => 'Error creating type specialization of a File-Type, Cannot use Integer where a resource title String is expected',
       "String[a]"                   => "A Type's size constraint arguments must be a single Integer type, or 1-2 integers (or default). Got a String",
       "Pattern[0]"                  => 'Error creating type specialization of a Pattern-Type, Cannot use Integer where String or Regexp or Pattern-Type or Regexp-Type is expected',
       "Regexp[0]"                   => 'Error creating type specialization of a Regexp-Type, Cannot use Integer where String or Regexp is expected',
       "Regexp[a,b]"                 => 'A Regexp-Type[] accepts 1 argument. Got 2',
       "true[0]"                     => "Operator '[]' is not applicable to a Boolean",
       "1[0]"                        => "Operator '[]' is not applicable to an Integer",
       "3.14[0]"                     => "Operator '[]' is not applicable to a Float",
       "/.*/[0]"                     => "Operator '[]' is not applicable to a Regexp",
       "[1][a]"                      => "The value 'a' cannot be converted to Numeric",
       "[1][0.0]"                    => "An Array[] cannot use Float where Integer is expected",
       "[1]['0.0']"                  => "An Array[] cannot use Float where Integer is expected",
       "[1,2][1, 0.0]"               => "An Array[] cannot use Float where Integer is expected",
       "[1,2][1.0, -1]"              => "An Array[] cannot use Float where Integer is expected",
       "[1,2][1, -1.0]"              => "An Array[] cannot use Float where Integer is expected",
     }.each do |source, result|
       it "should parse and evaluate the expression '#{source}' to #{result}" do
         expect { parser.evaluate_string(scope, source, __FILE__)}.to raise_error(Regexp.new(Regexp.quote(result)))
       end
     end
 
     context "on catalog types" do
       it "[n] gets resource parameter [n]" do
         source = "notify { 'hello': message=>'yo'} Notify[hello][message]"
         parser.evaluate_string(scope, source, __FILE__).should == 'yo'
       end
 
       it "[n] gets class parameter [n]" do
         source = "class wonka($produces='chocolate'){ }
            include wonka
            Class[wonka][produces]"
 
         # This is more complicated since it needs to run like 3.x and do an import_ast
         adapted_parser = Puppet::Parser::E4ParserAdapter.new
         adapted_parser.file = __FILE__
         ast = adapted_parser.parse(source)
         Puppet.override({:global_scope => scope}, "test") do
           scope.known_resource_types.import_ast(ast, '')
           ast.code.safeevaluate(scope).should == 'chocolate'
         end
       end
 
       # Resource default and override expressions and resource parameter access with []
       {
         # Properties
         "notify { id: message=>explicit} Notify[id][message]"                   => "explicit",
         "Notify { message=>by_default} notify {foo:} Notify[foo][message]"      => "by_default",
         "notify {foo:} Notify[foo]{message =>by_override} Notify[foo][message]" => "by_override",
         # Parameters
         "notify { id: withpath=>explicit} Notify[id][withpath]"                 => "explicit",
         "Notify { withpath=>by_default } notify { foo: } Notify[foo][withpath]" => "by_default",
         "notify {foo:}
          Notify[foo]{withpath=>by_override}
          Notify[foo][withpath]"                                                 => "by_override",
         # Metaparameters
         "notify { foo: tag => evoe} Notify[foo][tag]"                           => "evoe",
         # Does not produce the defaults for tag parameter (title, type or names of scopes)
         "notify { foo: } Notify[foo][tag]"                                      => nil,
         # But a default may be specified on the type
         "Notify { tag=>by_default } notify { foo: } Notify[foo][tag]"           => "by_default",
         "Notify { tag=>by_default }
          notify { foo: }
          Notify[foo]{ tag=>by_override }
          Notify[foo][tag]"                                                      => "by_override",
       }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
       # Virtual and realized resource default and overridden resource parameter access with []
       {
         # Properties
         "@notify { id: message=>explicit } Notify[id][message]"                 => "explicit",
         "@notify { id: message=>explicit }
          realize Notify[id]
          Notify[id][message]"                                                   => "explicit",
         "Notify { message=>by_default } @notify { id: } Notify[id][message]"    => "by_default",
         "Notify { message=>by_default }
          @notify { id: tag=>thisone }
          Notify <| tag == thisone |>;
          Notify[id][message]"                                                   => "by_default",
         "@notify { id: } Notify[id]{message=>by_override} Notify[id][message]"  => "by_override",
         # Parameters
         "@notify { id: withpath=>explicit } Notify[id][withpath]"               => "explicit",
         "Notify { withpath=>by_default }
          @notify { id: }
          Notify[id][withpath]"                                                  => "by_default",
         "@notify { id: }
          realize Notify[id]
          Notify[id]{withpath=>by_override}
          Notify[id][withpath]"                                                  => "by_override",
         # Metaparameters
         "@notify { id: tag=>explicit } Notify[id][tag]"                         => "explicit",
       }.each do |source, result|
         it "parses and evaluates virtual and realized resources in the expression '#{source}' to #{result}" do
           expect(parser.evaluate_string(scope, source, __FILE__)).to eq(result)
         end
       end
 
       # Exported resource attributes
       {
         "@@notify { id: message=>explicit } Notify[id][message]"                => "explicit",
         "@@notify { id: message=>explicit, tag=>thisone }
          Notify <<| tag == thisone |>>
          Notify[id][message]"                                                   => "explicit",
       }.each do |source, result|
         it "parses and evaluates exported resources in the expression '#{source}' to #{result}" do
           expect(parser.evaluate_string(scope, source, __FILE__)).to eq(result)
         end
       end
 
       # Resource default and override expressions and resource parameter access error conditions
       {
         "notify { xid: message=>explicit} Notify[id][message]"  => /Resource not found/,
         "notify { id: message=>explicit} Notify[id][mustard]"   => /does not have a parameter called 'mustard'/,
         # NOTE: these meta-esque parameters are not recognized as such
         "notify { id: message=>explicit} Notify[id][title]"   => /does not have a parameter called 'title'/,
         "notify { id: message=>explicit} Notify[id]['type']"   => /does not have a parameter called 'type'/,
         "notify { id: message=>explicit } Notify[id]{message=>override}" => /'message' is already set on Notify\[id\]/
       }.each do |source, result|
         it "should parse '#{source}' and raise error matching #{result}" do
           expect { parser.evaluate_string(scope, source, __FILE__)}.to raise_error(result)
         end
       end
 
       context 'with errors' do
         { "Class['fail-whale']" => /Illegal name/,
           "Class[0]"            => /An Integer cannot be used where a String is expected/,
           "Class[/.*/]"         => /A Regexp cannot be used where a String is expected/,
           "Class[4.1415]"       => /A Float cannot be used where a String is expected/,
           "Class[Integer]"      => /An Integer-Type cannot be used where a String is expected/,
           "Class[File['tmp']]"   => /A File\['tmp'\] Resource-Reference cannot be used where a String is expected/,
         }.each do | source, error_pattern|
           it "an error is flagged for '#{source}'" do
             expect { parser.evaluate_string(scope, source, __FILE__)}.to raise_error(error_pattern)
           end
         end
       end
     end
   # end [] operations
   end
 
   context "When the evaluator performs boolean operations" do
     {
       "true and true"   => true,
       "false and true"  => false,
       "true and false"  => false,
       "false and false" => false,
       "true or true"    => true,
       "false or true"   => true,
       "true or false"   => true,
       "false or false"  => false,
       "! true"          => false,
       "!! true"         => true,
       "!! false"        => false,
       "! 'x'"           => false,
       "! ''"            => false,
       "! undef"         => true,
       "! [a]"           => false,
       "! []"            => false,
       "! {a=>1}"        => false,
       "! {}"            => false,
       "true and false and '0xwtf' + 1"  => false,
       "false or true  or '0xwtf' + 1"  => true,
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     {
       "false || false || '0xwtf' + 1"   => :error,
     }.each do |source, result|
         it "should parse and raise error for '#{source}'" do
           expect { parser.evaluate_string(scope, source, __FILE__) }.to raise_error(Puppet::ParseError)
         end
       end
   end
 
   context "When evaluator performs operations on literal undef" do
     it "computes non existing hash lookup as undef" do
       parser.evaluate_string(scope, "{a => 1}[b] == undef", __FILE__).should == true
       parser.evaluate_string(scope, "undef == {a => 1}[b]", __FILE__).should == true
     end
   end
 
   context "When evaluator performs calls" do
 
     let(:populate) do
       parser.evaluate_string(scope, "$a = 10 $b = [1,2,3]")
     end
 
     {
       'sprintf( "x%iy", $a )'                 => "x10y",
       # unfolds
       'sprintf( *["x%iy", $a] )'              => "x10y",
       '"x%iy".sprintf( $a )'                  => "x10y",
       '$b.reduce |$memo,$x| { $memo + $x }'   => 6,
       'reduce($b) |$memo,$x| { $memo + $x }'  => 6,
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           populate
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     {
       '"value is ${a*2} yo"'  => :error,
     }.each do |source, result|
         it "should parse and raise error for '#{source}'" do
           expect { parser.evaluate_string(scope, source, __FILE__) }.to raise_error(Puppet::ParseError)
         end
       end
 
     it "provides location information on error in unparenthesized call logic" do
     expect{parser.evaluate_string(scope, "include non_existing_class", __FILE__)}.to raise_error(Puppet::ParseError, /line 1\:1/)
     end
 
     it 'defaults can be given in a lambda and used only when arg is missing' do
       env_loader = @compiler.loaders.public_environment_loader
       fc = Puppet::Functions.create_function(:test) do
         dispatch :test do
           param 'Integer', 'count'
           required_block_param
         end
         def test(count)
           yield(*[].fill(10, 0, count))
         end
       end
       the_func = fc.new({}, env_loader)
       env_loader.add_entry(:function, 'test', the_func, __FILE__)
       expect(parser.evaluate_string(scope, "test(1) |$x, $y=20| { $x + $y}")).to eql(30)
       expect(parser.evaluate_string(scope, "test(2) |$x, $y=20| { $x + $y}")).to eql(20)
     end
 
     it 'a given undef does not select the default value' do
       env_loader = @compiler.loaders.public_environment_loader
       fc = Puppet::Functions.create_function(:test) do
         dispatch :test do
           param 'Any', 'lambda_arg'
           required_block_param
         end
         def test(lambda_arg)
           yield(lambda_arg)
         end
       end
       the_func = fc.new({}, env_loader)
       env_loader.add_entry(:function, 'test', the_func, __FILE__)
 
       expect(parser.evaluate_string(scope, "test(undef) |$x=20| { $x == undef}")).to eql(true)
     end
 
     it 'a given undef is given as nil' do
       env_loader = @compiler.loaders.public_environment_loader
       fc = Puppet::Functions.create_function(:assert_no_undef) do
         dispatch :assert_no_undef do
           param 'Any', 'x'
         end
 
         def assert_no_undef(x)
           case x
           when Array
             return unless x.include?(:undef)
           when Hash
             return unless x.keys.include?(:undef) || x.values.include?(:undef)
           else
             return unless x == :undef
           end
           raise "contains :undef"
         end
       end
 
       the_func = fc.new({}, env_loader)
       env_loader.add_entry(:function, 'assert_no_undef', the_func, __FILE__)
 
       expect{parser.evaluate_string(scope, "assert_no_undef(undef)")}.to_not raise_error()
       expect{parser.evaluate_string(scope, "assert_no_undef([undef])")}.to_not raise_error()
       expect{parser.evaluate_string(scope, "assert_no_undef({undef => 1})")}.to_not raise_error()
       expect{parser.evaluate_string(scope, "assert_no_undef({1 => undef})")}.to_not raise_error()
     end
 
     context 'using the 3x function api' do
       it 'can call a 3x function' do
         Puppet::Parser::Functions.newfunction("bazinga", :type => :rvalue) { |args| args[0] }
         parser.evaluate_string(scope, "bazinga(42)", __FILE__).should == 42
       end
 
       it 'maps :undef to empty string' do
         Puppet::Parser::Functions.newfunction("bazinga", :type => :rvalue) { |args| args[0] }
         parser.evaluate_string(scope, "$a = {} bazinga($a[nope])", __FILE__).should == ''
         parser.evaluate_string(scope, "bazinga(undef)", __FILE__).should == ''
       end
 
       it 'does not map :undef to empty string in arrays' do
         Puppet::Parser::Functions.newfunction("bazinga", :type => :rvalue) { |args| args[0][0] }
         parser.evaluate_string(scope, "$a = {} $b = [$a[nope]] bazinga($b)", __FILE__).should == :undef
         parser.evaluate_string(scope, "bazinga([undef])", __FILE__).should == :undef
       end
 
       it 'does not map :undef to empty string in hashes' do
         Puppet::Parser::Functions.newfunction("bazinga", :type => :rvalue) { |args| args[0]['a'] }
         parser.evaluate_string(scope, "$a = {} $b = {a => $a[nope]} bazinga($b)", __FILE__).should == :undef
         parser.evaluate_string(scope, "bazinga({a => undef})", __FILE__).should == :undef
       end
     end
   end
 
   context "When evaluator performs string interpolation" do
     let(:populate) do
       parser.evaluate_string(scope, "$a = 10 $b = [1,2,3]")
     end
 
     {
       '"value is $a yo"'                      => "value is 10 yo",
       '"value is \$a yo"'                     => "value is $a yo",
       '"value is ${a} yo"'                    => "value is 10 yo",
       '"value is \${a} yo"'                   => "value is ${a} yo",
       '"value is ${$a} yo"'                   => "value is 10 yo",
       '"value is ${$a*2} yo"'                 => "value is 20 yo",
       '"value is ${sprintf("x%iy",$a)} yo"'   => "value is x10y yo",
       '"value is ${"x%iy".sprintf($a)} yo"'   => "value is x10y yo",
       '"value is ${[1,2,3]} yo"'              => "value is [1, 2, 3] yo",
       '"value is ${/.*/} yo"'                 => "value is /.*/ yo",
       '$x = undef "value is $x yo"'           => "value is  yo",
       '$x = default "value is $x yo"'         => "value is default yo",
       '$x = Array[Integer] "value is $x yo"'  => "value is Array[Integer] yo",
       '"value is ${Array[Integer]} yo"'       => "value is Array[Integer] yo",
     }.each do |source, result|
         it "should parse and evaluate the expression '#{source}' to #{result}" do
           populate
           parser.evaluate_string(scope, source, __FILE__).should == result
         end
       end
 
     it "should parse and evaluate an interpolation of a hash" do
       source = '"value is ${{a=>1,b=>2}} yo"'
       # This test requires testing against two options because a hash to string
       # produces a result that is unordered
       hashstr = {'a' => 1, 'b' => 2}.to_s
       alt_results = ["value is {a => 1, b => 2} yo", "value is {b => 2, a => 1} yo" ]
       populate
       parse_result = parser.evaluate_string(scope, source, __FILE__)
       alt_results.include?(parse_result).should == true
     end
 
     it 'should accept a variable with leading underscore when used directly' do
       source = '$_x = 10; "$_x"'
       expect(parser.evaluate_string(scope, source, __FILE__)).to eql('10')
     end
 
     it 'should accept a variable with leading underscore when used as an expression' do
       source = '$_x = 10; "${_x}"'
       expect(parser.evaluate_string(scope, source, __FILE__)).to eql('10')
     end
 
+    it 'should accept a numeric variable expressed as $n' do
+      source = '$x = "abc123def" =~ /(abc)(123)(def)/; "${$2}"'
+      expect(parser.evaluate_string(scope, source, __FILE__)).to eql('123')
+    end
+
+    it 'should accept a numeric variable expressed as just an integer' do
+      source = '$x = "abc123def" =~ /(abc)(123)(def)/; "${2}"'
+      expect(parser.evaluate_string(scope, source, __FILE__)).to eql('123')
+    end
+
+    it 'should accept a numeric variable expressed as $n in an access operation' do
+      source = '$x = "abc123def" =~ /(abc)(123)(def)/; "${$0[4,3]}"'
+      expect(parser.evaluate_string(scope, source, __FILE__)).to eql('23d')
+    end
+
+    it 'should accept a numeric variable expressed as just an integer in an access operation' do
+      source = '$x = "abc123def" =~ /(abc)(123)(def)/; "${0[4,3]}"'
+      expect(parser.evaluate_string(scope, source, __FILE__)).to eql('23d')
+    end
+
     {
       '"value is ${a*2} yo"'  => :error,
     }.each do |source, result|
         it "should parse and raise error for '#{source}'" do
           expect { parser.evaluate_string(scope, source, __FILE__) }.to raise_error(Puppet::ParseError)
         end
       end
   end
 
   context "When evaluating variables" do
     context "that are non existing an error is raised for" do
       it "unqualified variable" do
         expect { parser.evaluate_string(scope, "$quantum_gravity", __FILE__) }.to raise_error(/Unknown variable/)
       end
 
       it "qualified variable" do
         expect { parser.evaluate_string(scope, "$quantum_gravity::graviton", __FILE__) }.to raise_error(/Unknown variable/)
       end
     end
 
     it "a lex error should be raised for '$foo::::bar'" do
       expect { parser.evaluate_string(scope, "$foo::::bar") }.to raise_error(Puppet::LexError, /Illegal fully qualified name at line 1:7/)
     end
 
     { '$a = $0'   => nil,
       '$a = $1'   => nil,
     }.each do |source, value|
       it "it is ok to reference numeric unassigned variables '#{source}'" do
         parser.evaluate_string(scope, source, __FILE__).should == value
       end
     end
 
     { '$00 = 0'   => /must be a decimal value/,
       '$0xf = 0'  => /must be a decimal value/,
       '$0777 = 0' => /must be a decimal value/,
       '$123a = 0' => /must be a decimal value/,
     }.each do |source, error_pattern|
       it "should raise an error for '#{source}'" do
         expect { parser.evaluate_string(scope, source, __FILE__) }.to raise_error(error_pattern)
       end
     end
 
     context "an initial underscore in the last segment of a var name is allowed" do
       { '$_a  = 1'   => 1,
         '$__a = 1'   => 1,
       }.each do |source, value|
         it "as in this example '#{source}'" do
           parser.evaluate_string(scope, source, __FILE__).should == value
         end
       end
     end
   end
 
   context "When evaluating relationships" do
     it 'should form a relation with File[a] -> File[b]' do
       source = "File[a] -> File[b]"
       parser.evaluate_string(scope, source, __FILE__)
       scope.compiler.should have_relationship(['File', 'a', '->', 'File', 'b'])
     end
 
     it 'should form a relation with resource -> resource' do
       source = "notify{a:} -> notify{b:}"
       parser.evaluate_string(scope, source, __FILE__)
       scope.compiler.should have_relationship(['Notify', 'a', '->', 'Notify', 'b'])
     end
 
     it 'should form a relation with [File[a], File[b]] -> [File[x], File[y]]' do
       source = "[File[a], File[b]] -> [File[x], File[y]]"
       parser.evaluate_string(scope, source, __FILE__)
       scope.compiler.should have_relationship(['File', 'a', '->', 'File', 'x'])
       scope.compiler.should have_relationship(['File', 'b', '->', 'File', 'x'])
       scope.compiler.should have_relationship(['File', 'a', '->', 'File', 'y'])
       scope.compiler.should have_relationship(['File', 'b', '->', 'File', 'y'])
     end
 
     it 'should tolerate (eliminate) duplicates in operands' do
       source = "[File[a], File[a]] -> File[x]"
       parser.evaluate_string(scope, source, __FILE__)
       scope.compiler.should have_relationship(['File', 'a', '->', 'File', 'x'])
       scope.compiler.relationships.size.should == 1
     end
 
     it 'should form a relation with <-' do
       source = "File[a] <- File[b]"
       parser.evaluate_string(scope, source, __FILE__)
       scope.compiler.should have_relationship(['File', 'b', '->', 'File', 'a'])
     end
 
     it 'should form a relation with <-' do
       source = "File[a] <~ File[b]"
       parser.evaluate_string(scope, source, __FILE__)
       scope.compiler.should have_relationship(['File', 'b', '~>', 'File', 'a'])
     end
   end
 
   context "When evaluating heredoc" do
     it "evaluates plain heredoc" do
       src = "@(END)\nThis is\nheredoc text\nEND\n"
       parser.evaluate_string(scope, src).should == "This is\nheredoc text\n"
     end
 
     it "parses heredoc with margin" do
       src = [
       "@(END)",
       "   This is",
       "   heredoc text",
       "   | END",
       ""
       ].join("\n")
       parser.evaluate_string(scope, src).should == "This is\nheredoc text\n"
     end
 
     it "parses heredoc with margin and right newline trim" do
       src = [
       "@(END)",
       "   This is",
       "   heredoc text",
       "   |- END",
       ""
       ].join("\n")
       parser.evaluate_string(scope, src).should == "This is\nheredoc text"
     end
 
     it "parses escape specification" do
       src = <<-CODE
       @(END/t)
       Tex\\tt\\n
       |- END
       CODE
       parser.evaluate_string(scope, src).should == "Tex\tt\\n"
     end
 
     it "parses syntax checked specification" do
       src = <<-CODE
       @(END:json)
       ["foo", "bar"]
       |- END
       CODE
       parser.evaluate_string(scope, src).should == '["foo", "bar"]'
     end
 
     it "parses syntax checked specification with error and reports it" do
       src = <<-CODE
       @(END:json)
       ['foo', "bar"]
       |- END
       CODE
       expect { parser.evaluate_string(scope, src)}.to raise_error(/Cannot parse invalid JSON string/)
     end
 
     it "parses interpolated heredoc expression" do
       src = <<-CODE
       $name = 'Fjodor'
       @("END")
       Hello $name
       |- END
       CODE
       parser.evaluate_string(scope, src).should == "Hello Fjodor"
     end
 
   end
   context "Handles Deprecations and Discontinuations" do
     it 'of import statements' do
       source = "\nimport foo"
       # Error references position 5 at the opening '{'
       # Set file to nil to make it easier to match with line number (no file name in output)
       expect { parser.evaluate_string(scope, source) }.to raise_error(/'import' has been discontinued.*line 2:1/)
     end
   end
 
   context "Detailed Error messages are reported" do
     it 'for illegal type references' do
       source = '1+1 { "title": }'
       # Error references position 5 at the opening '{'
       # Set file to nil to make it easier to match with line number (no file name in output)
       expect { parser.evaluate_string(scope, source) }.to raise_error(
         /Illegal Resource Type expression, expected result to be a type name, or untitled Resource.*line 1:2/)
     end
 
     it 'for non r-value producing <| |>' do
       expect { parser.parse_string("$a = File <| |>", nil) }.to raise_error(/A Virtual Query does not produce a value at line 1:6/)
     end
 
     it 'for non r-value producing <<| |>>' do
       expect { parser.parse_string("$a = File <<| |>>", nil) }.to raise_error(/An Exported Query does not produce a value at line 1:6/)
     end
 
     it 'for non r-value producing define' do
       Puppet.expects(:err).with("Invalid use of expression. A 'define' expression does not produce a value at line 1:6")
       Puppet.expects(:err).with("Classes, definitions, and nodes may only appear at toplevel or inside other classes at line 1:6")
       expect { parser.parse_string("$a = define foo { }", nil) }.to raise_error(/2 errors/)
     end
 
     it 'for non r-value producing class' do
       Puppet.expects(:err).with("Invalid use of expression. A Host Class Definition does not produce a value at line 1:6")
       Puppet.expects(:err).with("Classes, definitions, and nodes may only appear at toplevel or inside other classes at line 1:6")
       expect { parser.parse_string("$a = class foo { }", nil) }.to raise_error(/2 errors/)
     end
 
     it 'for unclosed quote with indication of start position of string' do
       source = <<-SOURCE.gsub(/^ {6}/,'')
       $a = "xx
       yyy
       SOURCE
       # first char after opening " reported as being in error.
       expect { parser.parse_string(source) }.to raise_error(/Unclosed quote after '"' followed by 'xx\\nyy\.\.\.' at line 1:7/)
     end
 
     it 'for multiple errors with a summary exception' do
       Puppet.expects(:err).with("Invalid use of expression. A Node Definition does not produce a value at line 1:6")
       Puppet.expects(:err).with("Classes, definitions, and nodes may only appear at toplevel or inside other classes at line 1:6")
       expect { parser.parse_string("$a = node x { }",nil) }.to raise_error(/2 errors/)
     end
 
     it 'for a bad hostname' do
       expect {
         parser.parse_string("node 'macbook+owned+by+name' { }", nil)
       }.to raise_error(/The hostname 'macbook\+owned\+by\+name' contains illegal characters.*at line 1:6/)
     end
 
     it 'for a hostname with interpolation' do
       source = <<-SOURCE.gsub(/^ {6}/,'')
       $name = 'fred'
       node "macbook-owned-by$name" { }
       SOURCE
       expect {
         parser.parse_string(source, nil)
       }.to raise_error(/An interpolated expression is not allowed in a hostname of a node at line 2:23/)
     end
 
   end
 
   context 'does not leak variables' do
     it 'local variables are gone when lambda ends' do
       source = <<-SOURCE
       [1,2,3].each |$x| { $y = $x}
       $a = $y
       SOURCE
       expect do
         parser.evaluate_string(scope, source)
       end.to raise_error(/Unknown variable: 'y'/)
     end
 
     it 'lambda parameters are gone when lambda ends' do
       source = <<-SOURCE
       [1,2,3].each |$x| { $y = $x}
       $a = $x
       SOURCE
       expect do
         parser.evaluate_string(scope, source)
       end.to raise_error(/Unknown variable: 'x'/)
     end
 
     it 'does not leak match variables' do
       source = <<-SOURCE
       if 'xyz' =~ /(x)(y)(z)/ { notice $2 }
       case 'abc' {
         /(a)(b)(c)/ : { $x = $2 }
       }
       "-$x-$2-"
       SOURCE
       expect(parser.evaluate_string(scope, source)).to eq('-b--')
     end
   end
 
   matcher :have_relationship do |expected|
     calc = Puppet::Pops::Types::TypeCalculator.new
 
     match do |compiler|
       op_name = {'->' => :relationship, '~>' => :subscription}
       compiler.relationships.any? do | relation |
         relation.source.type == expected[0] &&
         relation.source.title == expected[1] &&
         relation.type == op_name[expected[2]] &&
         relation.target.type == expected[3] &&
         relation.target.title == expected[4]
       end
     end
 
     failure_message_for_should do |actual|
       "Relationship #{expected[0]}[#{expected[1]}] #{expected[2]} #{expected[3]}[#{expected[4]}] but was unknown to compiler"
     end
   end
 
 end