diff --git a/lib/puppet/pops/evaluator/evaluator_impl.rb b/lib/puppet/pops/evaluator/evaluator_impl.rb index ba70de197..ca76f60e2 100644 --- a/lib/puppet/pops/evaluator/evaluator_impl.rb +++ b/lib/puppet/pops/evaluator/evaluator_impl.rb @@ -1,1102 +1,1102 @@ require 'rgen/ecore/ecore' require 'puppet/pops/evaluator/compare_operator' require 'puppet/pops/evaluator/relationship_operator' require 'puppet/pops/evaluator/access_operator' require 'puppet/pops/evaluator/closure' require 'puppet/pops/evaluator/external_syntax_support' # This implementation of {Puppet::Pops::Evaluator} performs evaluation using the puppet 3.x runtime system # in a manner largely compatible with Puppet 3.x, but adds new features and introduces constraints. # # The evaluation uses _polymorphic dispatch_ which works by dispatching to the first found method named after # the class or one of its super-classes. The EvaluatorImpl itself mainly deals with evaluation (it currently # also handles assignment), and it uses a delegation pattern to more specialized handlers of some operators # that in turn use polymorphic dispatch; this to not clutter EvaluatorImpl with too much responsibility). # # Since a pattern is used, only the main entry points are fully documented. The parameters _o_ and _scope_ are # the same in all the polymorphic methods, (the type of the parameter _o_ is reflected in the method's name; # either the actual class, or one of its super classes). The _scope_ parameter is always the scope in which # the evaluation takes place. If nothing else is mentioned, the return is always the result of evaluation. # # See {Puppet::Pops::Visitable} and {Puppet::Pops::Visitor} for more information about # polymorphic calling. # class Puppet::Pops::Evaluator::EvaluatorImpl include Puppet::Pops::Utils # Provides access to the Puppet 3.x runtime (scope, etc.) # This separation has been made to make it easier to later migrate the evaluator to an improved runtime. # include Puppet::Pops::Evaluator::Runtime3Support include Puppet::Pops::Evaluator::ExternalSyntaxSupport # This constant is not defined as Float::INFINITY in Ruby 1.8.7 (but is available in later version # Refactor when support is dropped for Ruby 1.8.7. # INFINITY = 1.0 / 0.0 # Reference to Issues name space makes it easier to refer to issues # (Issues are shared with the validator). # Issues = Puppet::Pops::Issues def initialize @@eval_visitor ||= Puppet::Pops::Visitor.new(self, "eval", 1, 1) @@lvalue_visitor ||= Puppet::Pops::Visitor.new(self, "lvalue", 1, 1) @@assign_visitor ||= Puppet::Pops::Visitor.new(self, "assign", 3, 3) @@string_visitor ||= Puppet::Pops::Visitor.new(self, "string", 1, 1) @@type_calculator ||= Puppet::Pops::Types::TypeCalculator.new() @@type_parser ||= Puppet::Pops::Types::TypeParser.new() @@compare_operator ||= Puppet::Pops::Evaluator::CompareOperator.new() @@relationship_operator ||= Puppet::Pops::Evaluator::RelationshipOperator.new() # Initialize the runtime module Puppet::Pops::Evaluator::Runtime3Support.instance_method(:initialize).bind(self).call() end # @api private def type_calculator @@type_calculator end # Polymorphic evaluate - calls eval_TYPE # # ## Polymorphic evaluate # Polymorphic evaluate calls a method on the format eval_TYPE where classname is the last # part of the class of the given _target_. A search is performed starting with the actual class, continuing # with each of the _target_ class's super classes until a matching method is found. # # # Description # Evaluates the given _target_ object in the given scope, optionally passing a block which will be # called with the result of the evaluation. # # @overload evaluate(target, scope, {|result| block}) # @param target [Object] evaluation target - see methods on the pattern assign_TYPE for actual supported types. # @param scope [Object] the runtime specific scope class where evaluation should take place # @return [Object] the result of the evaluation # # @api # def evaluate(target, scope) begin @@eval_visitor.visit_this_1(self, target, scope) rescue StandardError => e if e.is_a? Puppet::ParseError raise e end fail(Issues::RUNTIME_ERROR, target, {:detail => e.message}, e) end end # Polymorphic assign - calls assign_TYPE # # ## Polymorphic assign # Polymorphic assign calls a method on the format assign_TYPE where TYPE is the last # part of the class of the given _target_. A search is performed starting with the actual class, continuing # with each of the _target_ class's super classes until a matching method is found. # # # Description # Assigns the given _value_ to the given _target_. The additional argument _o_ is the instruction that # produced the target/value tuple and it is used to set the origin of the result. # @param target [Object] assignment target - see methods on the pattern assign_TYPE for actual supported types. # @param value [Object] the value to assign to `target` # @param o [Puppet::Pops::Model::PopsObject] originating instruction # @param scope [Object] the runtime specific scope where evaluation should take place # # @api # def assign(target, value, o, scope) @@assign_visitor.visit_this_3(self, target, value, o, scope) end def lvalue(o, scope) @@lvalue_visitor.visit_this_1(self, o, scope) end def string(o, scope) @@string_visitor.visit_this_1(self, o, scope) end # Call a closure matching arguments by name - Can only be called with a Closure (for now), may be refactored later # to also handle other types of calls (function calls are also handled by CallNamedFunction and CallMethod, they # could create similar objects to Closure, wait until other types of defines are instantiated - they may behave # as special cases of calls - i.e. 'new'). # # Call by name supports a "spill_over" mode where extra arguments in the given args_hash are introduced # as variables in the resulting scope. # # @raise ArgumentError, if there are to many or too few arguments # @raise ArgumentError, if given closure is not a Puppet::Pops::Evaluator::Closure # def call_by_name(closure, args_hash, scope, spill_over = false) raise ArgumentError, "Can only call a Lambda" unless closure.is_a?(Puppet::Pops::Evaluator::Closure) pblock = closure.model parameters = pblock.parameters || [] if !spill_over && args_hash.size > parameters.size raise ArgumentError, "Too many arguments: #{args_hash.size} for #{parameters.size}" end # associate values with parameters scope_hash = {} parameters.each do |p| scope_hash[p.name] = args_hash[p.name] || evaluate(p.value, scope) end missing = scope_hash.reduce([]) {|memo, entry| memo << entry[0] if entry[1].nil?; memo } unless missing.empty? optional = parameters.count { |p| !p.value.nil? } raise ArgumentError, "Too few arguments; no value given for required parameters #{missing.join(" ,")}" end if spill_over # all args from given hash should be used, nil entries replaced by default values should win scope_hash = args_hash.merge(scope_hash) end # Store the evaluated name => value associations in a new inner/local/ephemeral scope # (This is made complicated due to the fact that the implementation of scope is overloaded with # functionality and an inner ephemeral scope must be used (as opposed to just pushing a local scope # on a scope "stack"). # Ensure variable exists with nil value if error occurs. # Some ruby implementations does not like creating variable on return result = nil begin scope_memo = get_scope_nesting_level(scope) # change to create local scope_from - cannot give it file and line - that is the place of the call, not # "here" create_local_scope_from(scope_hash, scope) result = evaluate(pblock.body, scope) ensure set_scope_nesting_level(scope, scope_memo) end result end # Call a closure - Can only be called with a Closure (for now), may be refactored later # to also handle other types of calls (function calls are also handled by CallNamedFunction and CallMethod, they # could create similar objects to Closure, wait until other types of defines are instantiated - they may behave # as special cases of calls - i.e. 'new') # # @raise ArgumentError, if there are to many or too few arguments # @raise ArgumentError, if given closure is not a Puppet::Pops::Evaluator::Closure # def call(closure, args, scope) raise ArgumentError, "Can only call a Lambda" unless closure.is_a?(Puppet::Pops::Evaluator::Closure) pblock = closure.model parameters = pblock.parameters || [] raise ArgumentError, "Too many arguments: #{args.size} for #{parameters.size}" unless args.size <= parameters.size # associate values with parameters merged = parameters.zip(args) # calculate missing arguments missing = parameters.slice(args.size, parameters.size - args.size).select {|p| p.value.nil? } unless missing.empty? optional = parameters.count { |p| !p.value.nil? } raise ArgumentError, "Too few arguments; #{args.size} for #{optional > 0 ? ' min ' : ''}#{parameters.size - optional}" end evaluated = merged.collect do |m| # m can be one of # m = [Parameter{name => "name", value => nil], "given"] # | [Parameter{name => "name", value => Expression}, "given"] # # "given" is always an optional entry. If a parameter was provided then # the entry will be in the array, otherwise the m array will be a # single element. given_argument = m[1] argument_name = m[0].name default_expression = m[0].value value = if default_expression evaluate(default_expression, scope) else given_argument end [argument_name, value] end # Store the evaluated name => value associations in a new inner/local/ephemeral scope # (This is made complicated due to the fact that the implementation of scope is overloaded with # functionality and an inner ephemeral scope must be used (as opposed to just pushing a local scope # on a scope "stack"). # Ensure variable exists with nil value if error occurs. # Some ruby implementations does not like creating variable on return result = nil begin scope_memo = get_scope_nesting_level(scope) # change to create local scope_from - cannot give it file and line - that is the place of the call, not # "here" create_local_scope_from(Hash[evaluated], scope) result = evaluate(pblock.body, scope) ensure set_scope_nesting_level(scope, scope_memo) end result end protected def lvalue_VariableExpression(o, scope) # evaluate the name evaluate(o.expr, scope) end # Catches all illegal lvalues # def lvalue_Object(o, scope) fail(Issues::ILLEGAL_ASSIGNMENT, o) end # Assign value to named variable. # The '$' sign is never part of the name. # @example In Puppet DSL # $name = value # @param name [String] name of variable without $ # @param value [Object] value to assign to the variable # @param o [Puppet::Pops::Model::PopsObject] originating instruction # @param scope [Object] the runtime specific scope where evaluation should take place # @return [value] # def assign_String(name, value, o, scope) if name =~ /::/ fail(Issues::CROSS_SCOPE_ASSIGNMENT, o.left_expr, {:name => name}) end set_variable(name, value, o, scope) value end def assign_Numeric(n, value, o, scope) fail(Issues::ILLEGAL_NUMERIC_ASSIGNMENT, o.left_expr, {:varname => n.to_s}) end # Catches all illegal assignment (e.g. 1 = 2, {'a'=>1} = 2, etc) # def assign_Object(name, value, o, scope) fail(Issues::ILLEGAL_ASSIGNMENT, o) end def eval_Factory(o, scope) evaluate(o.current, scope) end # Evaluates any object not evaluated to something else to itself. def eval_Object o, scope o end # Allows nil to be used as a Nop. # Evaluates to nil # TODO: What is the difference between literal undef, nil, and nop? # def eval_NilClass(o, scope) nil end # Evaluates Nop to nil. # TODO: or is this the same as :undef # TODO: is this even needed as a separate instruction when there is a literal undef? def eval_Nop(o, scope) nil end # Captures all LiteralValues not handled elsewhere. # def eval_LiteralValue(o, scope) o.value end def eval_LiteralDefault(o, scope) :default end def eval_LiteralUndef(o, scope) :undef # TODO: or just use nil for this? end # A QualifiedReference (i.e. a capitalized qualified name such as Foo, or Foo::Bar) evaluates to a PType # def eval_QualifiedReference(o, scope) @@type_parser.interpret(o) end def eval_NotExpression(o, scope) ! is_true?(evaluate(o.expr, scope)) end def eval_UnaryMinusExpression(o, scope) - coerce_numeric(evaluate(o.expr, scope), o, scope) end def eval_UnfoldExpression(o, scope) candidate = evaluate(o.expr, scope) case candidate when Array candidate when Hash candidate.to_a else # turns anything else into an array (so result can be unfolded) [candidate] end end # Abstract evaluation, returns array [left, right] with the evaluated result of left_expr and # right_expr # @return > array with result of evaluating left and right expressions # def eval_BinaryExpression o, scope [ evaluate(o.left_expr, scope), evaluate(o.right_expr, scope) ] end # Evaluates assignment with operators =, +=, -= and # # @example Puppet DSL # $a = 1 # $a += 1 # $a -= 1 # def eval_AssignmentExpression(o, scope) name = lvalue(o.left_expr, scope) value = evaluate(o.right_expr, scope) case o.operator when :'=' # regular assignment assign(name, value, o, scope) when :'+=' # if value does not exist and strict is on, looking it up fails, else it is nil or :undef existing_value = get_variable_value(name, o, scope) begin if existing_value.nil? || existing_value == :undef assign(name, value, o, scope) else # Delegate to calculate function to deal with check of LHS, and perform ´+´ as arithmetic or concatenation the # same way as ArithmeticExpression performs `+`. assign(name, calculate(existing_value, value, :'+', o.left_expr, o.right_expr, scope), o, scope) end rescue ArgumentError => e fail(Issues::APPEND_FAILED, o, {:message => e.message}) end when :'-=' # If an attempt is made to delete values from something that does not exists, the value is :undef (it is guaranteed to not # include any values the user wants deleted anyway :-) # # if value does not exist and strict is on, looking it up fails, else it is nil or :undef existing_value = get_variable_value(name, o, scope) begin if existing_value.nil? || existing_value == :undef assign(name, :undef, o, scope) else # Delegate to delete function to deal with check of LHS, and perform deletion assign(name, delete(get_variable_value(name, o, scope), value), o, scope) end rescue ArgumentError => e fail(Issues::APPEND_FAILED, o, {:message => e.message}, e) end else fail(Issues::UNSUPPORTED_OPERATOR, o, {:operator => o.operator}) end value end ARITHMETIC_OPERATORS = [:'+', :'-', :'*', :'/', :'%', :'<<', :'>>'] COLLECTION_OPERATORS = [:'+', :'-', :'<<'] # Handles binary expression where lhs and rhs are array/hash or numeric and operator is +, - , *, % / << >> # def eval_ArithmeticExpression(o, scope) left, right = eval_BinaryExpression(o, scope) begin result = calculate(left, right, o.operator, o.left_expr, o.right_expr, scope) rescue ArgumentError => e fail(Issues::RUNTIME_ERROR, o, {:detail => e.message}, e) end result end # Handles binary expression where lhs and rhs are array/hash or numeric and operator is +, - , *, % / << >> # def calculate(left, right, operator, left_o, right_o, scope) unless ARITHMETIC_OPERATORS.include?(operator) fail(Issues::UNSUPPORTED_OPERATOR, left_o.eContainer, {:operator => o.operator}) end if (left.is_a?(Array) || left.is_a?(Hash)) && COLLECTION_OPERATORS.include?(operator) # Handle operation on collections case operator when :'+' concatenate(left, right) when :'-' delete(left, right) when :'<<' unless left.is_a?(Array) fail(Issues::OPERATOR_NOT_APPLICABLE, left_o, {:operator => operator, :left_value => left}) end left + [right] end else # Handle operation on numeric left = coerce_numeric(left, left_o, scope) right = coerce_numeric(right, right_o, scope) begin if operator == :'%' && (left.is_a?(Float) || right.is_a?(Float)) # Deny users the fun of seeing severe rounding errors and confusing results fail(Issues::OPERATOR_NOT_APPLICABLE, left_o, {:operator => operator, :left_value => left}) end result = left.send(operator, right) rescue NoMethodError => e fail(Issues::OPERATOR_NOT_APPLICABLE, left_o, {:operator => operator, :left_value => left}) rescue ZeroDivisionError => e fail(Issues::DIV_BY_ZERO, right_o) end if result == INFINITY || result == -INFINITY fail(Issues::RESULT_IS_INFINITY, left_o, {:operator => operator}) end result end end def eval_EppExpression(o, scope) scope["@epp"] = [] evaluate(o.body, scope) result = scope["@epp"].join('') result end def eval_RenderStringExpression(o, scope) scope["@epp"] << o.value.dup nil end def eval_RenderExpression(o, scope) scope["@epp"] << string(evaluate(o.expr, scope), scope) nil end # Evaluates Puppet DSL ->, ~>, <-, and <~ def eval_RelationshipExpression(o, scope) # First level evaluation, reduction to basic data types or puppet types, the relationship operator then translates this # to the final set of references (turning strings into references, which can not naturally be done by the main evaluator since # all strings should not be turned into references. # real = eval_BinaryExpression(o, scope) @@relationship_operator.evaluate(real, o, scope) end # Evaluates x[key, key, ...] # def eval_AccessExpression(o, scope) left = evaluate(o.left_expr, scope) keys = o.keys.nil? ? [] : o.keys.collect {|key| evaluate(key, scope) } Puppet::Pops::Evaluator::AccessOperator.new(o).access(left, scope, *keys) end # Evaluates <, <=, >, >=, and == # def eval_ComparisonExpression o, scope left, right = eval_BinaryExpression o, scope begin # Left is a type if left.is_a?(Puppet::Pops::Types::PAbstractType) case o.operator when :'==' @@type_calculator.equals(left,right) when :'!=' !@@type_calculator.equals(left,right) when :'<' # left can be assigned to right, but they are not equal @@type_calculator.assignable?(right, left) && ! @@type_calculator.equals(left,right) when :'<=' # left can be assigned to right @@type_calculator.assignable?(right, left) when :'>' # right can be assigned to left, but they are not equal @@type_calculator.assignable?(left,right) && ! @@type_calculator.equals(left,right) when :'>=' # right can be assigned to left @@type_calculator.assignable?(left, right) else fail(Issues::UNSUPPORTED_OPERATOR, o, {:operator => o.operator}) end else case o.operator when :'==' @@compare_operator.equals(left,right) when :'!=' ! @@compare_operator.equals(left,right) when :'<' @@compare_operator.compare(left,right) < 0 when :'<=' @@compare_operator.compare(left,right) <= 0 when :'>' @@compare_operator.compare(left,right) > 0 when :'>=' @@compare_operator.compare(left,right) >= 0 else fail(Issues::UNSUPPORTED_OPERATOR, o, {:operator => o.operator}) end end rescue ArgumentError => e fail(Issues::COMPARISON_NOT_POSSIBLE, o, { :operator => o.operator, :left_value => left, :right_value => right, :detail => e.message}, e) end end # Evaluates matching expressions with type, string or regexp rhs expression. # If RHS is a type, the =~ matches compatible (assignable?) type. # # @example # x =~ /abc.*/ # @example # x =~ "abc.*/" # @example # y = "abc" # x =~ "${y}.*" # @example # [1,2,3] =~ Array[Integer[1,10]] # @return [Boolean] if a match was made or not. Also sets $0..$n to matchdata in current scope. # def eval_MatchExpression o, scope left, pattern = eval_BinaryExpression o, scope # matches RHS types as instance of for all types except a parameterized Regexp[R] if pattern.is_a?(Puppet::Pops::Types::PAbstractType) if pattern.is_a?(Puppet::Pops::Types::PRegexpType) && pattern.pattern # A qualified PRegexpType, get its ruby regexp pattern = pattern.regexp else # evaluate as instance? matched = @@type_calculator.instance?(pattern, left) # convert match result to Boolean true, or false return o.operator == :'=~' ? !!matched : !matched end end begin pattern = Regexp.new(pattern) unless pattern.is_a?(Regexp) rescue StandardError => e fail(Issues::MATCH_NOT_REGEXP, o.right_expr, {:detail => e.message}, e) end unless left.is_a?(String) fail(Issues::MATCH_NOT_STRING, o.left_expr, {:left_value => left}) end matched = pattern.match(left) # nil, or MatchData set_match_data(matched, o, scope) # creates ephemeral # convert match result to Boolean true, or false o.operator == :'=~' ? !!matched : !matched end # Evaluates Puppet DSL `in` expression # def eval_InExpression o, scope left, right = eval_BinaryExpression o, scope @@compare_operator.include?(right, left) end # @example # $a and $b # b is only evaluated if a is true # def eval_AndExpression o, scope is_true?(evaluate(o.left_expr, scope)) ? is_true?(evaluate(o.right_expr, scope)) : false end # @example # a or b # b is only evaluated if a is false # def eval_OrExpression o, scope is_true?(evaluate(o.left_expr, scope)) ? true : is_true?(evaluate(o.right_expr, scope)) end # Evaluates each entry of the literal list and creates a new Array # Supports unfolding of entries # @return [Array] with the evaluated content # def eval_LiteralList o, scope values = [] o.values.each do |v| if v.is_a?(Puppet::Pops::Model::UnfoldExpression) values.concat(evaluate(v, scope)) else values << evaluate(v, scope) end end values end # Evaluates each entry of the literal hash and creates a new Hash. # @return [Hash] with the evaluated content # def eval_LiteralHash o, scope h = Hash.new o.entries.each {|entry| h[ evaluate(entry.key, scope)]= evaluate(entry.value, scope)} h end # Evaluates all statements and produces the last evaluated value # def eval_BlockExpression o, scope r = nil o.statements.each {|s| r = evaluate(s, scope)} r end # Performs optimized search over case option values, lazily evaluating each # until there is a match. If no match is found, the case expression's default expression # is evaluated (it may be nil or Nop if there is no default, thus producing nil). # If an option matches, the result of evaluating that option is returned. # @return [Object, nil] what a matched option returns, or nil if nothing matched. # def eval_CaseExpression(o, scope) # memo scope level before evaluating test - don't want a match in the case test to leak $n match vars # to expressions after the case expression. # with_guarded_scope(scope) do test = evaluate(o.test, scope) result = nil the_default = nil if o.options.find do |co| # the first case option that matches if co.values.find do |c| the_default = co.then_expr if c.is_a? Puppet::Pops::Model::LiteralDefault is_match?(test, evaluate(c, scope), c, scope) end result = evaluate(co.then_expr, scope) true # the option was picked end end result # an option was picked, and produced a result else evaluate(the_default, scope) # evaluate the default (should be a nop/nil) if there is no default). end end end # Evaluates a CollectExpression by transforming it into a 3x AST::Collection and then evaluating that. # This is done because of the complex API between compiler, indirector, backends, and difference between # collecting virtual resources and exported resources. # def eval_CollectExpression o, scope # The Collect Expression and its contained query expressions are implemented in such a way in # 3x that it is almost impossible to do anything about them (the AST objects are lazily evaluated, # and the built structure consists of both higher order functions and arrays with query expressions # that are either used as a predicate filter, or given to an indirection terminus (such as the Puppet DB # resource terminus). Unfortunately, the 3x implementation has many inconsistencies that the implementation # below carries forward. # collect_3x = Puppet::Pops::Model::AstTransformer.new().transform(o) collected = collect_3x.evaluate(scope) # the 3x returns an instance of Parser::Collector (but it is only registered with the compiler at this # point and does not contain any valuable information (like the result) # Dilemma: If this object is returned, it is a first class value in the Puppet Language and we # need to be able to perform operations on it. We can forbid it from leaking by making CollectExpression # a non R-value. This makes it possible for the evaluator logic to make use of the Collector. collected end def eval_ParenthesizedExpression(o, scope) evaluate(o.expr, scope) end # This evaluates classes, nodes and resource type definitions to nil, since 3x: # instantiates them, and evaluates their parameters and body. This is achieved by # providing bridge AST classes in Puppet::Parser::AST::PopsBridge that bridges a # Pops Program and a Pops Expression. # # Since all Definitions are handled "out of band", they are treated as a no-op when # evaluated. # def eval_Definition(o, scope) nil end def eval_Program(o, scope) evaluate(o.body, scope) end # Produces Array[PObjectType], an array of resource references # def eval_ResourceExpression(o, scope) exported = o.exported virtual = o.virtual type_name = evaluate(o.type_name, scope) o.bodies.map do |body| titles = [evaluate(body.title, scope)].flatten evaluated_parameters = body.operations.map {|op| evaluate(op, scope) } create_resources(o, scope, virtual, exported, type_name, titles, evaluated_parameters) end.flatten.compact end def eval_ResourceOverrideExpression(o, scope) evaluated_resources = evaluate(o.resources, scope) evaluated_parameters = o.operations.map { |op| evaluate(op, scope) } create_resource_overrides(o, scope, [evaluated_resources].flatten, evaluated_parameters) evaluated_resources end # Produces 3x array of parameters def eval_AttributeOperation(o, scope) create_resource_parameter(o, scope, o.attribute_name, evaluate(o.value_expr, scope), o.operator) end # Sets default parameter values for a type, produces the type # def eval_ResourceDefaultsExpression(o, scope) type_name = o.type_ref.value # a QualifiedName's string value evaluated_parameters = o.operations.map {|op| evaluate(op, scope) } create_resource_defaults(o, scope, type_name, evaluated_parameters) # Produce the type evaluate(o.type_ref, scope) end # Evaluates function call by name. # def eval_CallNamedFunctionExpression(o, scope) # The functor expression is not evaluated, it is not possible to select the function to call # via an expression like $a() case o.functor_expr when Puppet::Pops::Model::QualifiedName # ok when Puppet::Pops::Model::RenderStringExpression # helpful to point out this easy to make Epp error fail(Issues::ILLEGAL_EPP_PARAMETERS, o) else fail(Issues::ILLEGAL_EXPRESSION, o.functor_expr, {:feature=>'function name', :container => o}) end name = o.functor_expr.value - assert_function_available(name, o, scope) + evaluated_arguments = [] o.arguments.each do |arg| if arg.is_a?(Puppet::Pops::Model::UnfoldExpression) evaluated_arguments.concat(evaluate(arg, scope)) else evaluated_arguments << evaluate(arg, scope) end end # wrap lambda in a callable block if it is present evaluated_arguments << Puppet::Pops::Evaluator::Closure.new(self, o.lambda, scope) if o.lambda call_function(name, evaluated_arguments, o, scope) end # Evaluation of CallMethodExpression handles a NamedAccessExpression functor (receiver.function_name) # def eval_CallMethodExpression(o, scope) unless o.functor_expr.is_a? Puppet::Pops::Model::NamedAccessExpression fail(Issues::ILLEGAL_EXPRESSION, o.functor_expr, {:feature=>'function accessor', :container => o}) end receiver = evaluate(o.functor_expr.left_expr, scope) name = o.functor_expr.right_expr unless name.is_a? Puppet::Pops::Model::QualifiedName fail(Issues::ILLEGAL_EXPRESSION, o.functor_expr, {:feature=>'function name', :container => o}) end name = name.value # the string function name - assert_function_available(name, o, scope) + evaluated_arguments = [receiver] (o.arguments || []).each do |arg| if arg.is_a?(Puppet::Pops::Model::UnfoldExpression) evaluated_arguments.concat(evaluate(arg, scope)) else evaluated_arguments << evaluate(arg, scope) end end # wrap lambda in a callable block if it is present evaluated_arguments << Puppet::Pops::Evaluator::Closure.new(self, o.lambda, scope) if o.lambda call_function(name, evaluated_arguments, o, scope) end # @example # $x ? { 10 => true, 20 => false, default => 0 } # def eval_SelectorExpression o, scope # memo scope level before evaluating test - don't want a match in the case test to leak $n match vars # to expressions after the selector expression. # with_guarded_scope(scope) do test = evaluate(o.left_expr, scope) selected = o.selectors.find do |s| candidate = evaluate(s.matching_expr, scope) candidate == :default || is_match?(test, candidate, s.matching_expr, scope) end if selected evaluate(selected.value_expr, scope) else nil end end end # SubLocatable is simply an expression that holds location information def eval_SubLocatedExpression o, scope evaluate(o.expr, scope) end # Evaluates Puppet DSL Heredoc def eval_HeredocExpression o, scope result = evaluate(o.text_expr, scope) assert_external_syntax(scope, result, o.syntax, o.text_expr) result end # Evaluates Puppet DSL `if` def eval_IfExpression o, scope with_guarded_scope(scope) do if is_true?(evaluate(o.test, scope)) evaluate(o.then_expr, scope) else evaluate(o.else_expr, scope) end end end # Evaluates Puppet DSL `unless` def eval_UnlessExpression o, scope with_guarded_scope(scope) do unless is_true?(evaluate(o.test, scope)) evaluate(o.then_expr, scope) else evaluate(o.else_expr, scope) end end end # Evaluates a variable (getting its value) # The evaluator is lenient; any expression producing a String is used as a name # of a variable. # def eval_VariableExpression o, scope # Evaluator is not too fussy about what constitutes a name as long as the result # is a String and a valid variable name # name = evaluate(o.expr, scope) # Should be caught by validation, but make this explicit here as well, or mysterious evaluation issues # may occur. case name when String when Numeric else fail(Issues::ILLEGAL_VARIABLE_EXPRESSION, o.expr) end # TODO: Check for valid variable name (Task for validator) # TODO: semantics of undefined variable in scope, this just returns what scope does == value or nil get_variable_value(name, o, scope) end # Evaluates double quoted strings that may contain interpolation # def eval_ConcatenatedString o, scope o.segments.collect {|expr| string(evaluate(expr, scope), scope)}.join end # If the wrapped expression is a QualifiedName, it is taken as the name of a variable in scope. # Note that this is different from the 3.x implementation, where an initial qualified name # is accepted. (e.g. `"---${var + 1}---"` is legal. This implementation requires such concrete # syntax to be expressed in a model as `(TextExpression (+ (Variable var) 1)` - i.e. moving the decision to # the parser. # # Semantics; the result of an expression is turned into a string, nil is silently transformed to empty # string. # @return [String] the interpolated result # def eval_TextExpression o, scope if o.expr.is_a?(Puppet::Pops::Model::QualifiedName) # TODO: formalize, when scope returns nil, vs error string(get_variable_value(o.expr.value, o, scope), scope) else string(evaluate(o.expr, scope), scope) end end def string_Object(o, scope) o.to_s end def string_Symbol(o, scope) case o when :undef '' else o.to_s end end def string_Array(o, scope) ['[', o.map {|e| string(e, scope)}.join(', '), ']'].join() end def string_Hash(o, scope) ['{', o.map {|k,v| string(k, scope) + " => " + string(v, scope)}.join(', '), '}'].join() end def string_Regexp(o, scope) ['/', o.source, '/'].join() end def string_PAbstractType(o, scope) @@type_calculator.string(o) end # Produces concatenation / merge of x and y. # # When x is an Array, y of type produces: # # * Array => concatenation `[1,2], [3,4] => [1,2,3,4]` # * Hash => concatenation of hash as array `[key, value, key, value, ...]` # * any other => concatenation of single value # # When x is a Hash, y of type produces: # # * Array => merge of array interpreted as `[key, value, key, value,...]` # * Hash => a merge, where entries in `y` overrides # * any other => error # # When x is something else, wrap it in an array first. # # When x is nil, an empty array is used instead. # # @note to concatenate an Array, nest the array - i.e. `[1,2], [[2,3]]` # # @overload concatenate(obj_x, obj_y) # @param obj_x [Object] object to wrap in an array and concatenate to; see other overloaded methods for return type # @param ary_y [Object] array to concatenate at end of `ary_x` # @return [Object] wraps obj_x in array before using other overloaded option based on type of obj_y # @overload concatenate(ary_x, ary_y) # @param ary_x [Array] array to concatenate to # @param ary_y [Array] array to concatenate at end of `ary_x` # @return [Array] new array with `ary_x` + `ary_y` # @overload concatenate(ary_x, hsh_y) # @param ary_x [Array] array to concatenate to # @param hsh_y [Hash] converted to array form, and concatenated to array # @return [Array] new array with `ary_x` + `hsh_y` converted to array # @overload concatenate (ary_x, obj_y) # @param ary_x [Array] array to concatenate to # @param obj_y [Object] non array or hash object to add to array # @return [Array] new array with `ary_x` + `obj_y` added as last entry # @overload concatenate(hsh_x, ary_y) # @param hsh_x [Hash] the hash to merge with # @param ary_y [Array] array interpreted as even numbered sequence of key, value merged with `hsh_x` # @return [Hash] new hash with `hsh_x` merged with `ary_y` interpreted as hash in array form # @overload concatenate(hsh_x, hsh_y) # @param hsh_x [Hash] the hash to merge to # @param hsh_y [Hash] hash merged with `hsh_x` # @return [Hash] new hash with `hsh_x` merged with `hsh_y` # @raise [ArgumentError] when `xxx_x` is neither an Array nor a Hash # @raise [ArgumentError] when `xxx_x` is a Hash, and `xxx_y` is neither Array nor Hash. # def concatenate(x, y) x = [x] unless x.is_a?(Array) || x.is_a?(Hash) case x when Array y = case y when Array then y when Hash then y.to_a else [y] end x + y # new array with concatenation when Hash y = case y when Hash then y when Array # Hash[[a, 1, b, 2]] => {} # Hash[a,1,b,2] => {a => 1, b => 2} # Hash[[a,1], [b,2]] => {[a,1] => [b,2]} # Hash[[[a,1], [b,2]]] => {a => 1, b => 2} # Use type calcultor to determine if array is Array[Array[?]], and if so use second form # of call t = @@type_calculator.infer(y) if t.element_type.is_a? Puppet::Pops::Types::PArrayType Hash[y] else Hash[*y] end else raise ArgumentError.new("Can only append Array or Hash to a Hash") end x.merge y # new hash with overwrite else raise ArgumentError.new("Can only append to an Array or a Hash.") end end # Produces the result x \ y (set difference) # When `x` is an Array, `y` is transformed to an array and then all matching elements removed from x. # When `x` is a Hash, all contained keys are removed from x as listed in `y` if it is an Array, or all its keys if it is a Hash. # The difference is returned. The given `x` and `y` are not modified by this operation. # @raise [ArgumentError] when `x` is neither an Array nor a Hash # def delete(x, y) result = x.dup case x when Array y = case y when Array then y when Hash then y.to_a else [y] end y.each {|e| result.delete(e) } when Hash y = case y when Array then y when Hash then y.keys else [y] end y.each {|e| result.delete(e) } else raise ArgumentError.new("Can only delete from an Array or Hash.") end result end # Implementation of case option matching. # # This is the type of matching performed in a case option, using == for every type # of value except regular expression where a match is performed. # def is_match? left, right, o, scope if right.is_a?(Regexp) return false unless left.is_a? String matched = right.match(left) set_match_data(matched, o, scope) # creates or clears ephemeral !!matched # convert to boolean elsif right.is_a?(Puppet::Pops::Types::PAbstractType) # right is a type and left is not - check if left is an instance of the given type # (The reverse is not terribly meaningful - computing which of the case options that first produces # an instance of a given type). # @@type_calculator.instance?(right, left) else # Handle equality the same way as the language '==' operator (case insensitive etc.) @@compare_operator.equals(left,right) end end def with_guarded_scope(scope) scope_memo = get_scope_nesting_level(scope) begin yield ensure set_scope_nesting_level(scope, scope_memo) end end end