Class: RBS::VarianceCalculator
Relationships & Source Files | |
Namespace Children | |
Classes:
| |
Inherits: | Object |
Defined in: | lib/rbs/variance_calculator.rb |
Class Method Summary
- .new(builder:) ⇒ VarianceCalculator constructor
Instance Attribute Summary
- #builder readonly
Instance Method Summary
Constructor Details
.new(builder:) ⇒ VarianceCalculator
# File 'lib/rbs/variance_calculator.rb', line 78
def initialize(builder:) @builder = builder end
Instance Attribute Details
#builder (readonly)
[ GitHub ]# File 'lib/rbs/variance_calculator.rb', line 76
attr_reader :builder
Instance Method Details
#env
[ GitHub ]# File 'lib/rbs/variance_calculator.rb', line 82
def env builder.env end
#function(type, result:, context:)
[ GitHub ]#in_inherit(name:, args:, variables:)
[ GitHub ]# File 'lib/rbs/variance_calculator.rb', line 98
def in_inherit(name:, args:, variables:) type = if name.class? Types::ClassInstance.new(name: name, args: args, location: nil) else Types::Interface.new(name: name, args: args, location: nil) end Result.new(variables: variables).tap do |result| type(type, result: result, context: :covariant) end end
#in_method_type(method_type:, variables:)
[ GitHub ]# File 'lib/rbs/variance_calculator.rb', line 86
def in_method_type(method_type:, variables:) result = Result.new(variables: variables) function(method_type.type, result: result, context: :covariant) if block = method_type.block function(block.type, result: result, context: :contravariant) end result end
#in_type_alias(name:)
[ GitHub ]# File 'lib/rbs/variance_calculator.rb', line 110
def in_type_alias(name:) env.normalized_type_name!(name) decl = env.type_alias_decls[name].decl or raise variables = decl.type_params.each.map(&:name) Result.new(variables: variables).tap do |result| type(decl.type, result: result, context: :covariant) end end
#negate(variance)
[ GitHub ]# File 'lib/rbs/variance_calculator.rb', line 176
def negate(variance) case variance when :invariant :invariant when :covariant :contravariant when :contravariant :covariant else raise end end
#type(type, result:, context:)
[ GitHub ]# File 'lib/rbs/variance_calculator.rb', line 121
def type(type, result:, context:) case type when Types::Variable if result.include?(type.name) case context when :covariant result.covariant(type.name) when :contravariant result.contravariant(type.name) when :invariant result.invariant(type.name) end end when Types::ClassInstance, Types::Interface, Types::Alias if type_name = env.normalize_type_name?(type.name) type_params = case type when Types::ClassInstance env.class_decls[type_name].type_params when Types::Interface env.interface_decls[type_name].decl.type_params when Types::Alias env.type_alias_decls[type_name].decl.type_params end type.args.each.with_index do |ty, i| if var = type_params[i] case var.variance when :invariant type(ty, result: result, context: :invariant) when :covariant type(ty, result: result, context: context) when :contravariant type(ty, result: result, context: negate(context)) end end end else raise NoTypeFoundError.new(type_name: type.name, location: type.location) end when Types::Proc function(type.type, result: result, context: context) else type.each_type do |ty| type(ty, result: result, context: context) end end end