diff --git a/lib/puppet/pops/issues.rb b/lib/puppet/pops/issues.rb
index 3fe06db12..f598ef9d7 100644
--- a/lib/puppet/pops/issues.rb
+++ b/lib/puppet/pops/issues.rb
@@ -1,549 +1,549 @@
 # Defines classes to deal with issues, and message formatting and defines constants with Issues.
 # @api public
 #
 module Puppet::Pops::Issues
   # Describes an issue, and can produce a message for an occurrence of the issue.
   #
   class Issue
     # The issue code
     # @return [Symbol]
     attr_reader :issue_code
 
     # A block producing the message
     # @return [Proc]
     attr_reader :message_block
 
     # Names that must be bound in an occurrence of the issue to be able to produce a message.
     # These are the names in addition to requirements stipulated by the Issue formatter contract; i.e. :label`,
     # and `:semantic`.
     #
     attr_reader :arg_names
 
     # If this issue can have its severity lowered to :warning, :deprecation, or :ignored
     attr_writer :demotable
     # Configures the Issue with required arguments (bound by occurrence), and a block producing a message.
     def initialize issue_code, *args, &block
       @issue_code = issue_code
       @message_block = block
       @arg_names = args
       @demotable = true
     end
 
     # Returns true if it is allowed to demote this issue
     def demotable?
       @demotable
     end
 
     # Formats a message for an occurrence of the issue with argument bindings passed in a hash.
     # The hash must contain a LabelProvider bound to the key `label` and the semantic model element
     # bound to the key `semantic`. All required arguments as specified by `arg_names` must be bound
     # in the given `hash`.
     # @api public
     #
     def format(hash ={})
       # Create a Message Data where all hash keys become methods for convenient interpolation
       # in issue text.
       msgdata = MessageData.new(*arg_names)
       begin
         # Evaluate the message block in the msg data's binding
         msgdata.format(hash, &message_block)
       rescue StandardError => e
         Puppet::Pops::Issues::MessageData
         raise RuntimeError, "Error while reporting issue: #{issue_code}. #{e.message}", caller
       end
     end
   end
 
   # Provides a binding of arguments passed to Issue.format to method names available
   # in the issue's message producing block.
   # @api private
   #
   class MessageData
     def initialize *argnames
       singleton = class << self; self end
       argnames.each do |name|
         singleton.send(:define_method, name) do
           @data[name]
         end
       end
     end
 
     def format(hash, &block)
       @data = hash
       instance_eval &block
     end
 
     # Returns the label provider given as a key in the hash passed to #format.
     # If given an argument, calls #label on the label provider (caller would otherwise have to
     # call label.label(it)
     #
     def label(it = nil)
       raise "Label provider key :label must be set to produce the text of the message!" unless @data[:label]
       it.nil? ? @data[:label] : @data[:label].label(it)
     end
 
     # Returns the label provider given as a key in the hash passed to #format.
     #
     def semantic
       raise "Label provider key :semantic must be set to produce the text of the message!" unless @data[:semantic]
       @data[:semantic]
     end
   end
 
   # Defines an issue with the given `issue_code`, additional required parameters, and a block producing a message.
   # The block is evaluated in the context of a MessageData which provides convenient access to all required arguments
   # via accessor methods. In addition to accessors for specified arguments, these are also available:
   # * `label` - a `LabelProvider` that provides human understandable names for model elements and production of article (a/an/the).
   # * `semantic` - the model element for which the issue is reported
   #
   # @param issue_code [Symbol] the issue code for the issue used as an identifier, should be the same as the constant
   #   the issue is bound to.
   # @param args [Symbol] required arguments that must be passed when formatting the message, may be empty
   # @param block [Proc] a block producing the message string, evaluated in a MessageData scope. The produced string
   #   should not end with a period as additional information may be appended.
   #
   # @see MessageData
   # @api public
   #
   def self.issue (issue_code, *args, &block)
     Issue.new(issue_code, *args, &block)
   end
 
   # Creates a non demotable issue.
   # @see Issue.issue
   #
   def self.hard_issue(issue_code, *args, &block)
     result = Issue.new(issue_code, *args, &block)
     result.demotable = false
     result
   end
 
   # @comment Here follows definitions of issues. The intent is to provide a list from which yardoc can be generated
   #   containing more detailed information / explanation of the issue.
   #   These issues are set as constants, but it is unfortunately not possible for the created object to easily know which
   #   name it is bound to. Instead the constant has to be repeated. (Alternatively, it could be done by instead calling
   #   #const_set on the module, but the extra work required to get yardoc output vs. the extra effort to repeat the name
   #   twice makes it not worth it (if doable at all, since there is no tag to artificially construct a constant, and
   #   the parse tag does not produce any result for a constant assignment).
 
   # This is allowed (3.1) and has not yet been deprecated.
   # @todo configuration
   #
   NAME_WITH_HYPHEN = issue :NAME_WITH_HYPHEN, :name do
     "#{label.a_an_uc(semantic)} may not have a name containing a hyphen. The name '#{name}' is not legal"
   end
 
   # When a variable name contains a hyphen and these are illegal.
   # It is possible to control if a hyphen is legal in a name or not using the setting TODO
   # @todo describe the setting
   # @api public
   # @todo configuration if this is error or warning
   #
   VAR_WITH_HYPHEN = issue :VAR_WITH_HYPHEN, :name do
     "A variable name may not contain a hyphen. The name '#{name}' is not legal"
   end
 
   # A class, definition, or node may only appear at top level or inside other classes
   # @todo Is this really true for nodes? Can they be inside classes? Isn't that too late?
   # @api public
   #
   NOT_TOP_LEVEL = hard_issue :NOT_TOP_LEVEL do
     "Classes, definitions, and nodes may only appear at toplevel or inside other classes"
   end
 
   CROSS_SCOPE_ASSIGNMENT = hard_issue :CROSS_SCOPE_ASSIGNMENT, :name do
     "Illegal attempt to assign to '#{name}'. Cannot assign to variables in other namespaces"
   end
 
   # Assignment can only be made to certain types of left hand expressions such as variables.
   ILLEGAL_ASSIGNMENT = hard_issue :ILLEGAL_ASSIGNMENT do
     "Illegal attempt to assign to '#{label.a_an(semantic)}'. Not an assignable reference"
   end
 
   # Variables are immutable, cannot reassign in the same assignment scope
   ILLEGAL_REASSIGNMENT = hard_issue :ILLEGAL_REASSIGNMENT, :name do
     "Cannot reassign variable #{name}"
   end
 
   ILLEGAL_RESERVED_ASSIGNMENT = hard_issue :ILLEGAL_RESERVED_ASSIGNMENT, :name do
     "Attempt to assign to a reserved variable name: '#{name}'"
   end
 
   # Assignment cannot be made to numeric match result variables
   ILLEGAL_NUMERIC_ASSIGNMENT = issue :ILLEGAL_NUMERIC_ASSIGNMENT, :varname do
     "Illegal attempt to assign to the numeric match result variable '$#{varname}'. Numeric variables are not assignable"
   end
 
   # parameters cannot have numeric names, clashes with match result variables
   ILLEGAL_NUMERIC_PARAMETER = issue :ILLEGAL_NUMERIC_PARAMETER, :name do
-    "The numeric parameter name '$#{varname}' cannot be used (clashes with numeric match result variables)"
+    "The numeric parameter name '$#{name}' cannot be used (clashes with numeric match result variables)"
   end
 
   # In certain versions of Puppet it may be allowed to assign to a not already assigned key
   # in an array or a hash. This is an optional validation that may be turned on to prevent accidental
   # mutation.
   #
   ILLEGAL_INDEXED_ASSIGNMENT = issue :ILLEGAL_INDEXED_ASSIGNMENT do
     "Illegal attempt to assign via [index/key]. Not an assignable reference"
   end
 
   # When indexed assignment ($x[]=) is allowed, the leftmost expression must be
   # a variable expression.
   #
   ILLEGAL_ASSIGNMENT_VIA_INDEX = hard_issue :ILLEGAL_ASSIGNMENT_VIA_INDEX do
     "Illegal attempt to assign to #{label.a_an(semantic)} via [index/key]. Not an assignable reference"
   end
 
   APPENDS_DELETES_NO_LONGER_SUPPORTED = hard_issue :APPENDS_DELETES_NO_LONGER_SUPPORTED, :operator do
     "The operator '#{operator}' is no longer supported. See http://links.puppetlabs.com/remove-plus-equals"
   end
 
   # For unsupported operators (e.g. += and -= in puppet 4).
   #
   UNSUPPORTED_OPERATOR = hard_issue :UNSUPPORTED_OPERATOR, :operator do
     "The operator '#{operator}' is not supported."
   end
 
   # For operators that are not supported in specific contexts (e.g. '* =>' in
   # resource defaults)
   #
   UNSUPPORTED_OPERATOR_IN_CONTEXT = hard_issue :UNSUPPORTED_OPERATOR_IN_CONTEXT, :operator do
     "The operator '#{operator}' in #{label.a_an(semantic)} is not supported."
   end
 
   # For non applicable operators (e.g. << on Hash).
   #
   OPERATOR_NOT_APPLICABLE = hard_issue :OPERATOR_NOT_APPLICABLE, :operator, :left_value do
     "Operator '#{operator}' is not applicable to #{label.a_an(left_value)}."
   end
 
   COMPARISON_NOT_POSSIBLE = hard_issue :COMPARISON_NOT_POSSIBLE, :operator, :left_value, :right_value, :detail do
     "Comparison of: #{label(left_value)} #{operator} #{label(right_value)}, is not possible. Caused by '#{detail}'."
   end
 
   MATCH_NOT_REGEXP = hard_issue :MATCH_NOT_REGEXP, :detail do
     "Can not convert right match operand to a regular expression. Caused by '#{detail}'."
   end
 
   MATCH_NOT_STRING = hard_issue :MATCH_NOT_STRING, :left_value do
     "Left match operand must result in a String value. Got #{label.a_an(left_value)}."
   end
 
   # Some expressions/statements may not produce a value (known as right-value, or rvalue).
   # This may vary between puppet versions.
   #
   NOT_RVALUE = issue :NOT_RVALUE do
     "Invalid use of expression. #{label.a_an_uc(semantic)} does not produce a value"
   end
 
   # Appending to attributes is only allowed in certain types of resource expressions.
   #
   ILLEGAL_ATTRIBUTE_APPEND = hard_issue :ILLEGAL_ATTRIBUTE_APPEND, :name, :parent do
     "Illegal +> operation on attribute #{name}. This operator can not be used in #{label.a_an(parent)}"
   end
 
   ILLEGAL_NAME = hard_issue :ILLEGAL_NAME, :name do
     "Illegal name. The given name #{name} does not conform to the naming rule /^((::)?[a-z_]\w*)(::[a-z]\w*)*$/"
   end
 
   ILLEGAL_VAR_NAME = hard_issue :ILLEGAL_VAR_NAME, :name do
     "Illegal variable name, The given name '#{name}' does not conform to the naming rule /^((::)?[a-z]\w*)*((::)?[a-z_]\w*)$/"
   end
 
   ILLEGAL_NUMERIC_VAR_NAME = hard_issue :ILLEGAL_NUMERIC_VAR_NAME, :name do
     "Illegal numeric variable name, The given name '#{name}' must be a decimal value if it starts with a digit 0-9"
   end
 
   # In case a model is constructed programmatically, it must create valid type references.
   #
   ILLEGAL_CLASSREF = hard_issue :ILLEGAL_CLASSREF, :name do
     "Illegal type reference. The given name '#{name}' does not conform to the naming rule"
   end
 
   # This is a runtime issue - storeconfigs must be on in order to collect exported. This issue should be
   # set to :ignore when just checking syntax.
   # @todo should be a :warning by default
   #
   RT_NO_STORECONFIGS = issue :RT_NO_STORECONFIGS do
     "You cannot collect exported resources without storeconfigs being set; the collection will be ignored"
   end
 
   # This is a runtime issue - storeconfigs must be on in order to export a resource. This issue should be
   # set to :ignore when just checking syntax.
   # @todo should be a :warning by default
   #
   RT_NO_STORECONFIGS_EXPORT = issue :RT_NO_STORECONFIGS_EXPORT do
     "You cannot collect exported resources without storeconfigs being set; the export is ignored"
   end
 
   # A hostname may only contain letters, digits, '_', '-', and '.'.
   #
   ILLEGAL_HOSTNAME_CHARS = hard_issue :ILLEGAL_HOSTNAME_CHARS, :hostname do
     "The hostname '#{hostname}' contains illegal characters (only letters, digits, '_', '-', and '.' are allowed)"
   end
 
   # A hostname may only contain letters, digits, '_', '-', and '.'.
   #
   ILLEGAL_HOSTNAME_INTERPOLATION = hard_issue :ILLEGAL_HOSTNAME_INTERPOLATION do
     "An interpolated expression is not allowed in a hostname of a node"
   end
 
   # Issues when an expression is used where it is not legal.
   # E.g. an arithmetic expression where a hostname is expected.
   #
   ILLEGAL_EXPRESSION = hard_issue :ILLEGAL_EXPRESSION, :feature, :container do
     "Illegal expression. #{label.a_an_uc(semantic)} is unacceptable as #{feature} in #{label.a_an(container)}"
   end
 
   # Issues when an expression is used where it is not legal.
   # E.g. an arithmetic expression where a hostname is expected.
   #
   ILLEGAL_VARIABLE_EXPRESSION = hard_issue :ILLEGAL_VARIABLE_EXPRESSION do
     "Illegal variable expression. #{label.a_an_uc(semantic)} did not produce a variable name (String or Numeric)."
   end
 
   # Issues when an expression is used illegaly in a query.
   # query only supports == and !=, and not <, > etc.
   #
   ILLEGAL_QUERY_EXPRESSION = hard_issue :ILLEGAL_QUERY_EXPRESSION do
     "Illegal query expression. #{label.a_an_uc(semantic)} cannot be used in a query"
   end
 
   # If an attempt is made to make a resource default virtual or exported.
   #
   NOT_VIRTUALIZEABLE = hard_issue :NOT_VIRTUALIZEABLE do
     "Resource Defaults are not virtualizable"
   end
 
   # When an attempt is made to use multiple keys (to produce a range in Ruby - e.g. $arr[2,-1]).
   # This is not supported in 3x, but it allowed in 4x.
   #
   UNSUPPORTED_RANGE = issue :UNSUPPORTED_RANGE, :count do
     "Attempt to use unsupported range in #{label.a_an(semantic)}, #{count} values given for max 1"
   end
 
   ILLEGAL_RELATIONSHIP_OPERAND_TYPE = issue :ILLEGAL_RELATIONSHIP_OPERAND_TYPE, :operand do
     "Illegal relationship operand, can not form a relationship with #{label.a_an(operand)}. A Catalog type is required."
   end
 
   NOT_CATALOG_TYPE = issue :NOT_CATALOG_TYPE, :type do
     "Illegal relationship operand, can not form a relationship with something of type #{type}. A Catalog type is required."
   end
 
   BAD_STRING_SLICE_ARITY = issue :BAD_STRING_SLICE_ARITY, :actual do
     "String supports [] with one or two arguments. Got #{actual}"
   end
 
   BAD_STRING_SLICE_TYPE = issue :BAD_STRING_SLICE_TYPE, :actual do
     "String-Type [] requires all arguments to be integers (or default). Got #{actual}"
   end
 
   BAD_ARRAY_SLICE_ARITY = issue :BAD_ARRAY_SLICE_ARITY, :actual do
     "Array supports [] with one or two arguments. Got #{actual}"
   end
 
   BAD_HASH_SLICE_ARITY = issue :BAD_HASH_SLICE_ARITY, :actual do
     "Hash supports [] with one or more arguments. Got #{actual}"
   end
 
   BAD_INTEGER_SLICE_ARITY = issue :BAD_INTEGER_SLICE_ARITY, :actual do
     "Integer-Type supports [] with one or two arguments (from, to). Got #{actual}"
   end
 
   BAD_INTEGER_SLICE_TYPE = issue :BAD_INTEGER_SLICE_TYPE, :actual do
     "Integer-Type [] requires all arguments to be integers (or default). Got #{actual}"
   end
 
   BAD_COLLECTION_SLICE_TYPE = issue :BAD_COLLECTION_SLICE_TYPE, :actual do
     "A Type's size constraint arguments must be a single Integer type, or 1-2 integers (or default). Got #{label.a_an(actual)}"
   end
 
   BAD_FLOAT_SLICE_ARITY = issue :BAD_INTEGER_SLICE_ARITY, :actual do
     "Float-Type supports [] with one or two arguments (from, to). Got #{actual}"
   end
 
   BAD_FLOAT_SLICE_TYPE = issue :BAD_INTEGER_SLICE_TYPE, :actual do
     "Float-Type [] requires all arguments to be floats, or integers (or default). Got #{actual}"
   end
 
   BAD_SLICE_KEY_TYPE = issue :BAD_SLICE_KEY_TYPE, :left_value, :expected_classes, :actual do
     expected_text = if expected_classes.size > 1
       "one of #{expected_classes.join(', ')} are"
     else
       "#{expected_classes[0]} is"
     end
     "#{label.a_an_uc(left_value)}[] cannot use #{actual} where #{expected_text} expected"
   end
 
   BAD_TYPE_SLICE_TYPE = issue :BAD_TYPE_SLICE_TYPE, :base_type, :actual do
     "#{base_type}[] arguments must be types. Got #{actual}"
   end
 
   BAD_TYPE_SLICE_ARITY = issue :BAD_TYPE_SLICE_ARITY, :base_type, :min, :max, :actual do
     base_type_label = base_type.is_a?(String) ? base_type : label.a_an_uc(base_type)
     if max == -1 || max == 1.0 / 0.0 # Infinity
       "#{base_type_label}[] accepts #{min} or more arguments. Got #{actual}"
     elsif max && max != min
       "#{base_type_label}[] accepts #{min} to #{max} arguments. Got #{actual}"
     else
       "#{base_type_label}[] accepts #{min} #{label.plural_s(min, 'argument')}. Got #{actual}"
     end
   end
 
   BAD_TYPE_SPECIALIZATION = hard_issue :BAD_TYPE_SPECIALIZATION, :type, :message do
     "Error creating type specialization of #{label.a_an(type)}, #{message}"
   end
 
   ILLEGAL_TYPE_SPECIALIZATION = issue :ILLEGAL_TYPE_SPECIALIZATION, :kind do
     "Cannot specialize an already specialized #{kind} type"
   end
 
   ILLEGAL_RESOURCE_SPECIALIZATION = issue :ILLEGAL_RESOURCE_SPECIALIZATION, :actual do
     "First argument to Resource[] must be a resource type or a String. Got #{actual}."
   end
 
   EMPTY_RESOURCE_SPECIALIZATION = issue :EMPTY_RESOURCE_SPECIALIZATION do
     "Arguments to Resource[] are all empty/undefined"
   end
 
   ILLEGAL_HOSTCLASS_NAME = hard_issue :ILLEGAL_HOSTCLASS_NAME, :name do
     "Illegal Class name in class reference. #{label.a_an_uc(name)} cannot be used where a String is expected"
   end
 
   ILLEGAL_DEFINITION_NAME = hard_issue :ILLEGAL_DEFINTION_NAME, :name do
     "Unacceptable name. The name '#{name}' is unacceptable as the name of #{label.a_an(semantic)}"
   end
 
   CAPTURES_REST_NOT_LAST = hard_issue :CAPTURES_REST_NOT_LAST, :param_name do
     "Parameter $#{param_name} is not last, and has 'captures rest'"
   end
 
   CAPTURES_REST_NOT_SUPPORTED = hard_issue :CAPTURES_REST_NOT_SUPPORTED, :container, :param_name do
     "Parameter $#{param_name} has 'captures rest' - not supported in #{label.a_an(container)}"
   end
 
   REQUIRED_PARAMETER_AFTER_OPTIONAL = hard_issue :REQUIRED_PARAMETER_AFTER_OPTIONAL, :param_name do
     "Parameter $#{param_name} is required but appears after optional parameters"
   end
 
   MISSING_REQUIRED_PARAMETER = hard_issue :MISSING_REQUIRED_PARAMETER, :param_name do
     "Parameter $#{param_name} is required but no value was given"
   end
 
   NOT_NUMERIC = issue :NOT_NUMERIC, :value do
     "The value '#{value}' cannot be converted to Numeric."
   end
 
   UNKNOWN_FUNCTION = issue :UNKNOWN_FUNCTION, :name do
     "Unknown function: '#{name}'."
   end
 
   UNKNOWN_VARIABLE = issue :UNKNOWN_VARIABLE, :name do
     "Unknown variable: '#{name}'."
   end
 
   RUNTIME_ERROR = issue :RUNTIME_ERROR, :detail do
     "Error while evaluating #{label.a_an(semantic)}, #{detail}"
   end
 
   UNKNOWN_RESOURCE_TYPE = issue :UNKNOWN_RESOURCE_TYPE, :type_name do
     "Resource type not found: #{type_name.capitalize}"
   end
 
   ILLEGAL_RESOURCE_TYPE = hard_issue :ILLEGAL_RESOURCE_TYPE, :actual do
     "Illegal Resource Type expression, expected result to be a type name, or untitled Resource, got #{actual}"
   end
 
   DUPLICATE_TITLE = issue :DUPLICATE_TITLE, :title  do
     "The title '#{title}' has already been used in this resource expression"
   end
 
   DUPLICATE_ATTRIBUTE = issue :DUPLICATE_ATTRIBUE, :attribute  do
     "The attribute '#{attribute}' has already been set in this resource body"
   end
 
   MISSING_TITLE = hard_issue :MISSING_TITLE do
     "Missing title. The title expression resulted in undef"
   end
 
   MISSING_TITLE_AT = hard_issue :MISSING_TITLE_AT, :index do
     "Missing title at index #{index}. The title expression resulted in an undef title"
   end
 
   ILLEGAL_TITLE_TYPE_AT = hard_issue :ILLEGAL_TITLE_TYPE_AT, :index, :actual do
     "Illegal title type at index #{index}. Expected String, got #{actual}"
   end
 
   EMPTY_STRING_TITLE_AT = hard_issue :EMPTY_STRING_TITLE_AT, :index do
     "Empty string title at #{index}. Title strings must have a length greater than zero."
   end
 
   UNKNOWN_RESOURCE = issue :UNKNOWN_RESOURCE, :type_name, :title do
     "Resource not found: #{type_name.capitalize}['#{title}']"
   end
 
   UNKNOWN_RESOURCE_PARAMETER = issue :UNKNOWN_RESOURCE_PARAMETER, :type_name, :title, :param_name do
     "The resource #{type_name.capitalize}['#{title}'] does not have a parameter called '#{param_name}'"
   end
 
   DIV_BY_ZERO = hard_issue :DIV_BY_ZERO do
     "Division by 0"
   end
 
   RESULT_IS_INFINITY = hard_issue :RESULT_IS_INFINITY, :operator do
     "The result of the #{operator} expression is Infinity"
   end
 
   # TODO_HEREDOC
   EMPTY_HEREDOC_SYNTAX_SEGMENT = issue :EMPTY_HEREDOC_SYNTAX_SEGMENT, :syntax do
     "Heredoc syntax specification has empty segment between '+' : '#{syntax}'"
   end
 
   ILLEGAL_EPP_PARAMETERS = issue :ILLEGAL_EPP_PARAMETERS do
     "Ambiguous EPP parameter expression. Probably missing '<%-' before parameters to remove leading whitespace"
   end
 
   DISCONTINUED_IMPORT = hard_issue :DISCONTINUED_IMPORT do
     "Use of 'import' has been discontinued in favor of a manifest directory. See http://links.puppetlabs.com/puppet-import-deprecation"
   end
 
   IDEM_EXPRESSION_NOT_LAST = issue :IDEM_EXPRESSION_NOT_LAST do
     "This #{label.label(semantic)} is not productive. A non productive construct may only be placed last in a block/sequence"
   end
 
   IDEM_NOT_ALLOWED_LAST = hard_issue :IDEM_NOT_ALLOWED_LAST, :container do
     "This #{label.label(semantic)} is not productive. #{label.a_an_uc(container)} can not end with a non productive construct"
   end
 
   RESERVED_WORD = hard_issue :RESERVED_WORD, :word do
     "Use of reserved word: #{word}, must be quoted if intended to be a String value"
   end
 
   RESERVED_TYPE_NAME = hard_issue :RESERVED_TYPE_NAME, :name do
     "The name: '#{name}' is already defined by Puppet and can not be used as the name of #{label.a_an(semantic)}."
   end
 
   UNMATCHED_SELECTOR = hard_issue :UNMATCHED_SELECTOR, :param_value do
     "No matching entry for selector parameter with value '#{param_value}'"
   end
 
   ILLEGAL_NODE_INHERITANCE = issue :ILLEGAL_NODE_INHERITANCE do
     "Node inheritance is not supported in Puppet >= 4.0.0. See http://links.puppetlabs.com/puppet-node-inheritance-deprecation"
   end
 
   ILLEGAL_OVERRIDEN_TYPE = issue :ILLEGAL_OVERRIDEN_TYPE, :actual do
     "Resource Override can only operate on resources, got: #{label.label(actual)}"
   end
 
   RESERVED_PARAMETER = hard_issue :RESERVED_PARAMETER, :container, :param_name do
     "The parameter $#{param_name} redefines a built in parameter in #{label.the(container)}"
   end
 
   TYPE_MISMATCH = hard_issue :TYPE_MISMATCH, :expected, :actual do
     "Expected value of type #{expected}, got #{actual}"
   end
 
   MULTIPLE_ATTRIBUTES_UNFOLD = hard_issue :MULTIPLE_ATTRIBUTES_UNFOLD do
     "Unfolding of attributes from Hash can only be used once per resource body"
   end
 end
diff --git a/lib/puppet/pops/validation/checker4_0.rb b/lib/puppet/pops/validation/checker4_0.rb
index 91342bc4b..079710d59 100644
--- a/lib/puppet/pops/validation/checker4_0.rb
+++ b/lib/puppet/pops/validation/checker4_0.rb
@@ -1,760 +1,760 @@
 # 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 =~ /^[0-9]+$/
+    if o.name =~ /^(?:0x)?[0-9]+$/
       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)
       acceptor.accept(Issues::ILLEGAL_EXPRESSION, o, :feature => 'name', :container => o)
     else
       # name must be either a decimal 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/validator/validator_spec.rb b/spec/unit/pops/validator/validator_spec.rb
index ec0b0be4c..31defdd6b 100644
--- a/spec/unit/pops/validator/validator_spec.rb
+++ b/spec/unit/pops/validator/validator_spec.rb
@@ -1,175 +1,184 @@
 #! /usr/bin/env ruby
 require 'spec_helper'
 require 'puppet/pops'
 require 'puppet_spec/pops'
 
 # relative to this spec file (./) does not work as this file is loaded by rspec
 require File.join(File.dirname(__FILE__), '../parser/parser_rspec_helper')
 
 describe "validating 4x" do
   include ParserRspecHelper
   include PuppetSpec::Pops
 
   let(:acceptor) { Puppet::Pops::Validation::Acceptor.new() }
   let(:validator) { Puppet::Pops::Validation::ValidatorFactory_4_0.new().validator(acceptor) }
 
   def validate(model)
     validator.validate(model)
     acceptor
   end
 
   it 'should raise error for illegal names' do
     pending "validation was too strict, now too relaxed - validation missing"
     expect(validate(fqn('Aaa'))).to have_issue(Puppet::Pops::Issues::ILLEGAL_NAME)
     expect(validate(fqn('AAA'))).to have_issue(Puppet::Pops::Issues::ILLEGAL_NAME)
   end
 
   it 'should raise error for illegal variable names' do
     expect(validate(fqn('Aaa').var())).to have_issue(Puppet::Pops::Issues::ILLEGAL_VAR_NAME)
     expect(validate(fqn('AAA').var())).to have_issue(Puppet::Pops::Issues::ILLEGAL_VAR_NAME)
     expect(validate(fqn('aaa::_aaa').var())).to have_issue(Puppet::Pops::Issues::ILLEGAL_VAR_NAME)
   end
 
   it 'should not raise error for variable name with underscore first in first name segment' do
     expect(validate(fqn('_aa').var())).to_not have_issue(Puppet::Pops::Issues::ILLEGAL_VAR_NAME)
     expect(validate(fqn('::_aa').var())).to_not have_issue(Puppet::Pops::Issues::ILLEGAL_VAR_NAME)
   end
 
   context 'for non productive expressions' do
     [ '1',
       '3.14',
       "'a'",
       '"a"',
       '"${$a=10}"', # interpolation with side effect
       'false',
       'true',
       'default',
       'undef',
       '[1,2,3]',
       '{a=>10}',
       'if 1 {2}',
       'if 1 {2} else {3}',
       'if 1 {2} elsif 3 {4}',
       'unless 1 {2}',
       'unless 1 {2} else {3}',
       '1 ? 2 => 3',
       '1 ? { 2 => 3}',
       '-1',
       '-foo()', # unary minus on productive
       '1+2',
       '1<2',
       '(1<2)',
       '!true',
       '!foo()', # not on productive
       '$a',
       '$a[1]',
       'name',
       'Type',
       'Type[foo]'
       ].each do |expr|
       it "produces error for non productive: #{expr}" do
         source = "#{expr}; $a = 10"
         expect(validate(parse(source))).to have_issue(Puppet::Pops::Issues::IDEM_EXPRESSION_NOT_LAST)
       end
 
       it "does not produce error when last for non productive: #{expr}" do
         source = " $a = 10; #{expr}"
         expect(validate(parse(source))).to_not have_issue(Puppet::Pops::Issues::IDEM_EXPRESSION_NOT_LAST)
       end
     end
 
     [
       'if 1 {$a = 1}',
       'if 1 {2} else {$a=1}',
       'if 1 {2} elsif 3 {$a=1}',
       'unless 1 {$a=1}',
       'unless 1 {2} else {$a=1}',
       '$a = 1 ? 2 => 3',
       '$a = 1 ? { 2 => 3}',
       'Foo[a] -> Foo[b]',
       '($a=1)',
       'foo()',
       '$a.foo()'
       ].each do |expr|
 
       it "does not produce error when for productive: #{expr}" do
         source = "#{expr}; $x = 1"
         expect(validate(parse(source))).to_not have_issue(Puppet::Pops::Issues::IDEM_EXPRESSION_NOT_LAST)
       end
     end
 
     ['class', 'define', 'node'].each do |type|
       it "flags non productive expression last in #{type}" do
         source = <<-SOURCE
           #{type} nope {
             1
           }
           end
         SOURCE
         expect(validate(parse(source))).to have_issue(Puppet::Pops::Issues::IDEM_NOT_ALLOWED_LAST)
       end
     end
   end
 
   context 'for reserved words' do
     ['function', 'private', 'type', 'attr'].each do |word|
       it "produces an error for the word '#{word}'" do
         source = "$a = #{word}"
         expect(validate(parse(source))).to have_issue(Puppet::Pops::Issues::RESERVED_WORD)
       end
     end
   end
 
   context 'for reserved type names' do
     [# type/Type, is a reserved name but results in syntax error because it is a keyword in lower case form
     'any',
     'unit',
     'scalar',
     'boolean',
     'numeric',
     'integer',
     'float',
     'collection',
     'array',
     'hash',
     'tuple',
     'struct',
     'variant',
     'optional',
     'enum',
     'regexp',
     'pattern',
     'runtime',
     ].each do |name|
 
       it "produces an error for 'class #{name}'" do
         source = "class #{name} {}"
         expect(validate(parse(source))).to have_issue(Puppet::Pops::Issues::RESERVED_TYPE_NAME)
       end
 
       it "produces an error for 'define #{name}'" do
         source = "define #{name} {}"
         expect(validate(parse(source))).to have_issue(Puppet::Pops::Issues::RESERVED_TYPE_NAME)
       end
     end
   end
 
   context 'for reserved parameter names' do
     ['name', 'title'].each do |word|
       it "produces an error when $#{word} is used as a parameter in a class" do
         source = "class x ($#{word}) {}"
         expect(validate(parse(source))).to have_issue(Puppet::Pops::Issues::RESERVED_PARAMETER)
       end
 
       it "produces an error when $#{word} is used as a parameter in a define" do
         source = "define x ($#{word}) {}"
         expect(validate(parse(source))).to have_issue(Puppet::Pops::Issues::RESERVED_PARAMETER)
       end
     end
 
   end
 
+  context 'for numeric parameter names' do
+    ['1', '0x2', '03'].each do |word|
+      it "produces an error when $#{word} is used as a parameter in a class" do
+        source = "class x ($#{word}) {}"
+        expect(validate(parse(source))).to have_issue(Puppet::Pops::Issues::ILLEGAL_NUMERIC_PARAMETER)
+      end
+    end
+  end
+
   def parse(source)
     Puppet::Pops::Parser::Parser.new().parse_string(source)
   end
 end