diff --git a/lib/puppet/parser/scope.rb b/lib/puppet/parser/scope.rb index 2f89ffe8d..f5c427427 100644 --- a/lib/puppet/parser/scope.rb +++ b/lib/puppet/parser/scope.rb @@ -1,935 +1,947 @@ # The scope class, which handles storing and retrieving variables and types and # such. require 'forwardable' require 'puppet/parser' require 'puppet/parser/templatewrapper' require 'puppet/resource/type_collection_helper' require 'puppet/util/methodhelper' # This class is part of the internal parser/evaluator/compiler functionality of Puppet. # It is passed between the various classes that participate in evaluation. # None of its methods are API except those that are clearly marked as such. # # @api public class Puppet::Parser::Scope extend Forwardable include Puppet::Util::MethodHelper include Puppet::Resource::TypeCollectionHelper require 'puppet/parser/resource' AST = Puppet::Parser::AST # Variables that always exist with nil value even if not set BUILT_IN_VARS = ['module_name'.freeze, 'caller_module_name'.freeze].freeze Puppet::Util.logmethods(self) include Puppet::Util::Errors attr_accessor :source, :resource attr_accessor :compiler attr_accessor :parent attr_reader :namespaces # Hash of hashes of default values per type name attr_reader :defaults # Add some alias methods that forward to the compiler, since we reference # them frequently enough to justify the extra method call. def_delegators :compiler, :catalog, :environment # Abstract base class for LocalScope and MatchScope # class Ephemeral attr_reader :parent def initialize(parent = nil) @parent = parent end def is_local_scope? false end def [](name) if @parent @parent[name] end end def include?(name) (@parent and @parent.include?(name)) end def bound?(name) false end def add_entries_to(target = {}) @parent.add_entries_to(target) unless @parent.nil? # do not include match data ($0-$n) target end end class LocalScope < Ephemeral def initialize(parent=nil) super parent @symbols = {} end def [](name) if @symbols.include?(name) @symbols[name] else super end end def is_local_scope? true end def []=(name, value) @symbols[name] = value end def include?(name) bound?(name) || super end def delete(name) @symbols.delete(name) end def bound?(name) @symbols.include?(name) end def add_entries_to(target = {}) super @symbols.each do |k, v| if v == :undef || v.nil? target.delete(k) else target[ k ] = v end end target end end class MatchScope < Ephemeral attr_accessor :match_data def initialize(parent = nil, match_data = nil) super parent @match_data = match_data end def is_local_scope? false end def [](name) if bound?(name) @match_data[name.to_i] else super end end def include?(name) bound?(name) or super end def bound?(name) # A "match variables" scope reports all numeric variables to be bound if the scope has # match_data. Without match data the scope is transparent. # @match_data && name =~ /^\d+$/ end def []=(name, value) # TODO: Bad choice of exception raise Puppet::ParseError, "Numerical variables cannot be changed. Attempt to set $#{name}" end def delete(name) # TODO: Bad choice of exception raise Puppet::ParseError, "Numerical variables cannot be deleted: Attempt to delete: $#{name}" end def add_entries_to(target = {}) # do not include match data ($0-$n) super end end # Returns true if the variable of the given name has a non nil value. # TODO: This has vague semantics - does the variable exist or not? # use ['name'] to get nil or value, and if nil check with exist?('name') # this include? is only useful because of checking against the boolean value false. # def include?(name) ! self[name].nil? end # Returns true if the variable of the given name is set to any value (including nil) # # @return [Boolean] if variable exists or not # def exist?(name) # Note !! ensure the answer is boolean !! if name =~ /^(.*)::(.+)$/ class_name = $1 variable_name = $2 return true if class_name == '' && BUILT_IN_VARS.include?(variable_name) # lookup class, but do not care if it is not evaluated since that will result # in it not existing anyway. (Tests may run with just scopes and no evaluated classes which # will result in class_scope for "" not returning topscope). klass = find_hostclass(class_name) other_scope = klass.nil? ? nil : class_scope(klass) if other_scope.nil? class_name == '' ? compiler.topscope.exist?(variable_name) : false else other_scope.exist?(variable_name) end else next_scope = inherited_scope || enclosing_scope effective_symtable(true).include?(name) || next_scope && next_scope.exist?(name) || BUILT_IN_VARS.include?(name) end end # Returns true if the given name is bound in the current (most nested) scope for assignments. # def bound?(name) # Do not look in ephemeral (match scope), the semantics is to answer if an assignable variable is bound effective_symtable(false).bound?(name) end # Is the value true? This allows us to control the definition of truth # in one place. def self.true?(value) case value when '' false when :undef false else !!value end end # Coerce value to a number, or return `nil` if it isn't one. def self.number?(value) case value when Numeric value when /^-?\d+(:?\.\d+|(:?\.\d+)?e\d+)$/ value.to_f when /^0x[0-9a-f]+$/i value.to_i(16) when /^0[0-7]+$/ value.to_i(8) when /^-?\d+$/ value.to_i else nil end end # Add to our list of namespaces. def add_namespace(ns) return false if @namespaces.include?(ns) if @namespaces == [""] @namespaces = [ns] else @namespaces << ns end end def find_hostclass(name, options = {}) known_resource_types.find_hostclass(namespaces, name, options) end def find_definition(name) known_resource_types.find_definition(namespaces, name) end def find_global_scope() # walk upwards until first found node_scope or top_scope if is_nodescope? || is_topscope? self else next_scope = inherited_scope || enclosing_scope if next_scope.nil? # this happens when testing, and there is only a single test scope and no link to any # other scopes self else next_scope.find_global_scope() end end end # This just delegates directly. def_delegator :compiler, :findresource # Initialize our new scope. Defaults to having no parent. def initialize(compiler, options = {}) if compiler.is_a? Puppet::Parser::Compiler self.compiler = compiler else raise Puppet::DevError, "you must pass a compiler instance to a new scope object" end if n = options.delete(:namespace) @namespaces = [n] else @namespaces = [""] end raise Puppet::DevError, "compiler passed in options" if options.include? :compiler set_options(options) extend_with_functions_module # The symbol table for this scope. This is where we store variables. # @symtable = Ephemeral.new(nil, true) @symtable = LocalScope.new(nil) @ephemeral = [ MatchScope.new(@symtable, nil) ] # All of the defaults set for types. It's a hash of hashes, # with the first key being the type, then the second key being # the parameter. @defaults = Hash.new { |dhash,type| dhash[type] = {} } # The table for storing class singletons. This will only actually # be used by top scopes and node scopes. @class_scopes = {} @enable_immutable_data = Puppet[:immutable_node_data] end # Store the fact that we've evaluated a class, and store a reference to # the scope in which it was evaluated, so that we can look it up later. def class_set(name, scope) if parent parent.class_set(name, scope) else @class_scopes[name] = scope end end # Return the scope associated with a class. This is just here so # that subclasses can set their parent scopes to be the scope of # their parent class, and it's also used when looking up qualified # variables. def class_scope(klass) # They might pass in either the class or class name k = klass.respond_to?(:name) ? klass.name : klass @class_scopes[k] || (parent && parent.class_scope(k)) end # Collect all of the defaults set at any higher scopes. # This is a different type of lookup because it's # additive -- it collects all of the defaults, with defaults # in closer scopes overriding those in later scopes. # # The lookupdefaults searches in the the order: # # * inherited # * contained (recursive) # * self # def lookupdefaults(type) values = {} # first collect the values from the parents if parent parent.lookupdefaults(type).each { |var,value| values[var] = value } end # then override them with any current values # this should probably be done differently if @defaults.include?(type) @defaults[type].each { |var,value| values[var] = value } end values end # Look up a defined type. def lookuptype(name) find_definition(name) || find_hostclass(name) end def undef_as(x,v) if v.nil? or v == :undef x else v end end # Lookup a variable within this scope using the Puppet language's # scoping rules. Variables can be qualified using just as in a # manifest. # # @param [String] name the variable name to lookup # # @return Object the value of the variable, or nil if it's not found # # @api public def lookupvar(name, options = {}) unless name.is_a? String raise Puppet::ParseError, "Scope variable name #{name.inspect} is a #{name.class}, not a string" end table = @ephemeral.last if name =~ /^(.*)::(.+)$/ class_name = $1 variable_name = $2 lookup_qualified_variable(class_name, variable_name, options) # TODO: optimize with an assoc instead, this searches through scopes twice for a hit elsif table.include?(name) table[name] else next_scope = inherited_scope || enclosing_scope if next_scope next_scope.lookupvar(name, options) else variable_not_found(name) end end end def variable_not_found(name, reason=nil) # Built in variables always exist if BUILT_IN_VARS.include?(name) return nil end if Puppet[:strict_variables] if Puppet.future_parser? throw :undefined_variable else reason_msg = reason.nil? ? '' : "; #{reason}" raise Puppet::ParseError, "Undefined variable #{name.inspect}#{reason_msg}" end else nil end end # Retrieves the variable value assigned to the name given as an argument. The name must be a String, # and namespace can be qualified with '::'. The value is looked up in this scope, its parent scopes, # or in a specific visible named scope. # # @param varname [String] the name of the variable (may be a qualified name using `(ns'::')*varname` # @param options [Hash] Additional options, not part of api. # @return [Object] the value assigned to the given varname # @see #[]= # @api public # def [](varname, options={}) lookupvar(varname, options) end # The scope of the inherited thing of this scope's resource. This could # either be a node that was inherited or the class. # # @return [Puppet::Parser::Scope] The scope or nil if there is not an inherited scope def inherited_scope if has_inherited_class? qualified_scope(resource.resource_type.parent) else nil end end # The enclosing scope (topscope or nodescope) of this scope. # The enclosing scopes are produced when a class or define is included at # some point. The parent scope of the included class or define becomes the # scope in which it was included. The chain of parent scopes is followed # until a node scope or the topscope is found # # @return [Puppet::Parser::Scope] The scope or nil if there is no enclosing scope def enclosing_scope if has_enclosing_scope? if parent.is_topscope? or parent.is_nodescope? parent else parent.enclosing_scope end else nil end end def is_classscope? resource and resource.type == "Class" end def is_nodescope? resource and resource.type == "Node" end def is_topscope? compiler and self == compiler.topscope end def lookup_qualified_variable(class_name, variable_name, position) begin if lookup_as_local_name?(class_name, variable_name) - self[variable_name] + if is_topscope? + # This is the case where $::x is looked up from within the topscope itself, or from a local scope + # parented at the top scope. In this case, the lookup must ignore local and ephemeral scopes. + # + handle_not_found(class_name, variable_name, position) unless @symtable.include?(variable_name) + @symtable[variable_name] + else + self[variable_name] + end else qualified_scope(class_name).lookupvar(variable_name, position) end rescue RuntimeError => e - unless Puppet[:strict_variables] - # Do not issue warning if strict variables are on, as an error will be raised by variable_not_found - location = if position[:lineproc] - " at #{position[:lineproc].call}" - elsif position[:file] && position[:line] - " at #{position[:file]}:#{position[:line]}" - else - "" - end - warning "Could not look up qualified variable '#{class_name}::#{variable_name}'; #{e.message}#{location}" - end - variable_not_found("#{class_name}::#{variable_name}", e.message) + handle_not_found(class_name, variable_name, position, e.message) + end + end + + def handle_not_found(class_name, variable_name, position, reason = nil) + unless Puppet[:strict_variables] + # Do not issue warning if strict variables are on, as an error will be raised by variable_not_found + location = if position[:lineproc] + " at #{position[:lineproc].call}" + elsif position[:file] && position[:line] + " at #{position[:file]}:#{position[:line]}" + else + "" + end + warning "Could not look up qualified variable '#{class_name}::#{variable_name}'; #{reason}#{location}" end + variable_not_found("#{class_name}::#{variable_name}", reason) end # Handles the special case of looking up fully qualified variable in not yet evaluated top scope # This is ok if the lookup request originated in topscope (this happens when evaluating # bindings; using the top scope to provide the values for facts. # @param class_name [String] the classname part of a variable name, may be special "" # @param variable_name [String] the variable name without the absolute leading '::' # @return [Boolean] true if the given variable name should be looked up directly in this scope # def lookup_as_local_name?(class_name, variable_name) # not a local if name has more than one segment return nil if variable_name =~ /::/ # partial only if the class for "" cannot be found return nil unless class_name == "" && klass = find_hostclass(class_name) && class_scope(klass).nil? is_topscope? end def has_inherited_class? is_classscope? and resource.resource_type.parent end private :has_inherited_class? def has_enclosing_scope? not parent.nil? end private :has_enclosing_scope? def qualified_scope(classname) raise "class #{classname} could not be found" unless klass = find_hostclass(classname) raise "class #{classname} has not been evaluated" unless kscope = class_scope(klass) kscope end private :qualified_scope # Returns a Hash containing all variables and their values, optionally (and # by default) including the values defined in parent. Local values # shadow parent values. Ephemeral scopes for match results ($0 - $n) are not included. # # This is currently a wrapper for to_hash_legacy or to_hash_future. # # @see to_hash_future # # @see to_hash_legacy def to_hash(recursive = true) @future_parser ||= Puppet.future_parser? if @future_parser to_hash_future(recursive) else to_hash_legacy(recursive) end end # Fixed version of to_hash that implements scoping correctly (i.e., with # dynamic scoping disabled #28200 / PUP-1220 # # @see to_hash def to_hash_future(recursive) if recursive and has_enclosing_scope? target = enclosing_scope.to_hash_future(recursive) if !(inherited = inherited_scope).nil? target.merge!(inherited.to_hash_future(recursive)) end else target = Hash.new end # add all local scopes @ephemeral.last.add_entries_to(target) target end # The old broken implementation of to_hash that retains the dynamic scoping # semantics # # @see to_hash def to_hash_legacy(recursive = true) if recursive and parent target = parent.to_hash_legacy(recursive) else target = Hash.new end # add all local scopes @ephemeral.last.add_entries_to(target) target end def namespaces @namespaces.dup end # Create a new scope and set these options. def newscope(options = {}) compiler.newscope(self, options) end def parent_module_name return nil unless @parent return nil unless @parent.source @parent.source.module_name end # Set defaults for a type. The typename should already be downcased, # so that the syntax is isolated. We don't do any kind of type-checking # here; instead we let the resource do it when the defaults are used. def define_settings(type, params) table = @defaults[type] # if we got a single param, it'll be in its own array params = [params] unless params.is_a?(Array) params.each { |param| if table.include?(param.name) raise Puppet::ParseError.new("Default already defined for #{type} { #{param.name} }; cannot redefine", param.line, param.file) end table[param.name] = param } end RESERVED_VARIABLE_NAMES = ['trusted', 'facts'].freeze # Set a variable in the current scope. This will override settings # in scopes above, but will not allow variables in the current scope # to be reassigned. # It's preferred that you use self[]= instead of this; only use this # when you need to set options. def setvar(name, value, options = {}) if name =~ /^[0-9]+$/ raise Puppet::ParseError.new("Cannot assign to a numeric match result variable '$#{name}'") # unless options[:ephemeral] end unless name.is_a? String raise Puppet::ParseError, "Scope variable name #{name.inspect} is a #{name.class}, not a string" end # Check for reserved variable names if @enable_immutable_data && !options[:privileged] && RESERVED_VARIABLE_NAMES.include?(name) raise Puppet::ParseError, "Attempt to assign to a reserved variable name: '#{name}'" end table = effective_symtable(options[:ephemeral]) if table.bound?(name) if options[:append] error = Puppet::ParseError.new("Cannot append, variable #{name} is defined in this scope") else error = Puppet::ParseError.new("Cannot reassign variable #{name}") end error.file = options[:file] if options[:file] error.line = options[:line] if options[:line] raise error end if options[:append] # produced result (value) is the resulting appended value, note: the table[]= does not return the value table[name] = (value = append_value(undef_as('', self[name]), value)) else table[name] = value end value end def set_trusted(hash) setvar('trusted', deep_freeze(hash), :privileged => true) end def set_facts(hash) # Remove _timestamp (it has an illegal datatype). It is not allowed to mutate the given hash # since it contains the facts. hash = hash.dup hash.delete('_timestamp') setvar('facts', deep_freeze(hash), :privileged => true) end # Deeply freezes the given object. The object and its content must be of the types: # Array, Hash, Numeric, Boolean, Symbol, Regexp, NilClass, or String. All other types raises an Error. # (i.e. if they are assignable to Puppet::Pops::Types::Data type). # def deep_freeze(object) case object when Array object.each {|v| deep_freeze(v) } object.freeze when Hash object.each {|k, v| deep_freeze(k); deep_freeze(v) } object.freeze when NilClass, Numeric, TrueClass, FalseClass # do nothing when String object.freeze else raise Puppet::Error, "Unsupported data type: '#{object.class}'" end object end private :deep_freeze # Return the effective "table" for setting variables. # This method returns the first ephemeral "table" that acts as a local scope, or this # scope's symtable. If the parameter `use_ephemeral` is true, the "top most" ephemeral "table" # will be returned (irrespective of it being a match scope or a local scope). # # @param use_ephemeral [Boolean] whether the top most ephemeral (of any kind) should be used or not def effective_symtable(use_ephemeral) s = @ephemeral.last if use_ephemeral return s || @symtable else while s && !s.is_local_scope?() s = s.parent end s || @symtable end end # Sets the variable value of the name given as an argument to the given value. The value is # set in the current scope and may shadow a variable with the same name in a visible outer scope. # It is illegal to re-assign a variable in the same scope. It is illegal to set a variable in some other # scope/namespace than the scope passed to a method. # # @param varname [String] The variable name to which the value is assigned. Must not contain `::` # @param value [String] The value to assign to the given variable name. # @param options [Hash] Additional options, not part of api. # # @api public # def []=(varname, value, options = {}) setvar(varname, value, options = {}) end def append_value(bound_value, new_value) case new_value when Array bound_value + new_value when Hash bound_value.merge(new_value) else if bound_value.is_a?(Hash) raise ArgumentError, "Trying to append to a hash with something which is not a hash is unsupported" end bound_value + new_value end end private :append_value # Return the tags associated with this scope. def_delegator :resource, :tags # Used mainly for logging def to_s "Scope(#{@resource})" end alias_method :inspect, :to_s # remove ephemeral scope up to level # TODO: Who uses :all ? Remove ?? # def unset_ephemeral_var(level=:all) if level == :all @ephemeral = [ MatchScope.new(@symtable, nil)] else @ephemeral.pop(@ephemeral.size - level) end end def ephemeral_level @ephemeral.size end # TODO: Who calls this? def new_ephemeral(local_scope = false) if local_scope @ephemeral.push(LocalScope.new(@ephemeral.last)) else @ephemeral.push(MatchScope.new(@ephemeral.last, nil)) end end # Sets match data in the most nested scope (which always is a MatchScope), it clobbers match data already set there # def set_match_data(match_data) @ephemeral.last.match_data = match_data end # Nests a match data scope def new_match_scope(match_data) @ephemeral.push(MatchScope.new(@ephemeral.last, match_data)) end def ephemeral_from(match, file = nil, line = nil) case match when Hash # Create local scope ephemeral and set all values from hash new_ephemeral(true) match.each {|k,v| setvar(k, v, :file => file, :line => line, :ephemeral => true) } # Must always have an inner match data scope (that starts out as transparent) # In 3x slightly wasteful, since a new nested scope is created for a match # (TODO: Fix that problem) new_ephemeral(false) else raise(ArgumentError,"Invalid regex match data. Got a #{match.class}") unless match.is_a?(MatchData) # Create a match ephemeral and set values from match data new_match_scope(match) end end def find_resource_type(type) # It still works fine without the type == 'class' short-cut, but it is a lot slower. return nil if ["class", "node"].include? type.to_s.downcase find_builtin_resource_type(type) || find_defined_resource_type(type) end def find_builtin_resource_type(type) Puppet::Type.type(type.to_s.downcase.to_sym) end def find_defined_resource_type(type) known_resource_types.find_definition(namespaces, type.to_s.downcase) end def method_missing(method, *args, &block) method.to_s =~ /^function_(.*)$/ name = $1 super unless name super unless Puppet::Parser::Functions.function(name) # In odd circumstances, this might not end up defined by the previous # method, so we might as well be certain. if respond_to? method send(method, *args) else raise Puppet::DevError, "Function #{name} not defined despite being loaded!" end end def resolve_type_and_titles(type, titles) raise ArgumentError, "titles must be an array" unless titles.is_a?(Array) case type.downcase when "class" # resolve the titles titles = titles.collect do |a_title| hostclass = find_hostclass(a_title) hostclass ? hostclass.name : a_title end when "node" # no-op else # resolve the type resource_type = find_resource_type(type) type = resource_type.name if resource_type end return [type, titles] end # Transforms references to classes to the form suitable for # lookup in the compiler. # # Makes names passed in the names array absolute if they are relative # Names are now made absolute if Puppet.future_parser? is true, this will # be the default behavior in Puppet 4.0 # # Transforms Class[] and Resource[] type referenes to class name # or raises an error if a Class[] is unspecific, if a Resource is not # a 'class' resource, or if unspecific (no title). # # TODO: Change this for 4.0 to always make names absolute # # @param names [Array] names to (optionally) make absolute # @return [Array] names after transformation # def transform_and_assert_classnames(names) if Puppet.future_parser? names.map do |name| case name when String name.sub(/^([^:]{1,2})/, '::\1') when Puppet::Resource assert_class_and_title(name.type, name.title) name.title.sub(/^([^:]{1,2})/, '::\1') when Puppet::Pops::Types::PHostClassType raise ArgumentError, "Cannot use an unspecific Class[] Type" unless name.class_name name.class_name.sub(/^([^:]{1,2})/, '::\1') when Puppet::Pops::Types::PResourceType assert_class_and_title(name.type_name, name.title) name.title.sub(/^([^:]{1,2})/, '::\1') end end else names end end private def assert_class_and_title(type_name, title) if type_name.nil? || type_name == '' raise ArgumentError, "Cannot use an unspecific Resource[] where a Resource['class', name] is expected" end unless type_name =~ /^[Cc]lass$/ raise ArgumentError, "Cannot use a Resource[#{type_name}] where a Resource['class', name] is expected" end if title.nil? raise ArgumentError, "Cannot use an unspecific Resource['class'] where a Resource['class', name] is expected" end end def extend_with_functions_module root = Puppet.lookup(:root_environment) extend Puppet::Parser::Functions.environment_module(root) extend Puppet::Parser::Functions.environment_module(environment) if environment != root end end diff --git a/spec/unit/pops/evaluator/variables_spec.rb b/spec/unit/pops/evaluator/variables_spec.rb index 6c1e9f821..f4fca03aa 100644 --- a/spec/unit/pops/evaluator/variables_spec.rb +++ b/spec/unit/pops/evaluator/variables_spec.rb @@ -1,89 +1,89 @@ #! /usr/bin/env ruby require 'spec_helper' require 'puppet/pops' require 'puppet/pops/evaluator/evaluator_impl' # This file contains basic testing of variable references and assignments # using a top scope and a local scope. # It does not test variables and named scopes. # # 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::Impl::EvaluatorImpl' do include EvaluatorRspecHelper context "When the evaluator deals with variables" do context "it should handle" do it "simple assignment and dereference" do evaluate_l(block( var('a').set(literal(2)+literal(2)), var('a'))).should == 4 end it "local scope shadows top scope" do top_scope_block = block( var('a').set(literal(2)+literal(2)), var('a')) local_scope_block = block( var('a').set(var('a') + literal(2)), var('a')) evaluate_l(top_scope_block, local_scope_block).should == 6 end it "shadowed in local does not affect parent scope" do top_scope_block = block( var('a').set(literal(2)+literal(2)), var('a')) local_scope_block = block( var('a').set(var('a') + literal(2)), var('a')) top_scope_again = var('a') evaluate_l(top_scope_block, local_scope_block, top_scope_again).should == 4 end it "access to global names works in top scope" do top_scope_block = block( var('a').set(literal(2)+literal(2)), var('::a')) evaluate_l(top_scope_block).should == 4 end it "access to global names works in local scope" do top_scope_block = block( var('a').set(literal(2)+literal(2))) - local_scope_block = block( var('a').set(var('::a')+literal(2)), var('::a')) + local_scope_block = block( var('a').set(literal(100)), var('b').set(var('::a')+literal(2)), var('b')) evaluate_l(top_scope_block, local_scope_block).should == 6 end it "can not change a variable value in same scope" do expect { evaluate_l(block(var('a').set(10), var('a').set(20))) }.to raise_error(/Cannot reassign variable a/) end context "access to numeric variables" do it "without a match" do evaluate_l(block(literal(2) + literal(2), [var(0), var(1), var(2), var(3)])).should == [nil, nil, nil, nil] end it "after a match" do evaluate_l(block(literal('abc') =~ literal(/(a)(b)(c)/), [var(0), var(1), var(2), var(3)])).should == ['abc', 'a', 'b', 'c'] end it "after a failed match" do evaluate_l(block(literal('abc') =~ literal(/(x)(y)(z)/), [var(0), var(1), var(2), var(3)])).should == [nil, nil, nil, nil] end it "a failed match does not alter previous match" do evaluate_l(block( literal('abc') =~ literal(/(a)(b)(c)/), literal('abc') =~ literal(/(x)(y)(z)/), [var(0), var(1), var(2), var(3)])).should == ['abc', 'a', 'b', 'c'] end it "a new match completely shadows previous match" do evaluate_l(block( literal('abc') =~ literal(/(a)(b)(c)/), literal('abc') =~ literal(/(a)bc/), [var(0), var(1), var(2), var(3)])).should == ['abc', 'a', nil, nil] end it "after a match with variable referencing a non existing group" do evaluate_l(block(literal('abc') =~ literal(/(a)(b)(c)/), [var(0), var(1), var(2), var(3), var(4)])).should == ['abc', 'a', 'b', 'c', nil] end end end end end