3.1. Advanced Types#

TypeName = (* variant: *) ArrayTypeName
         | (* variant: *) FunctionType
         | (* variant: *) MappingType
         | (* variant: *) ElementaryType
         | (* variant: *) IdentifierPath;

(* Postfix unary operator *)
ArrayTypeName = (* operand: *) TypeName
                (* open_bracket: *) OPEN_BRACKET
                (* index: *) Expression?
                (* close_bracket: *) CLOSE_BRACKET;

FunctionType = (* function_keyword: *) FUNCTION_KEYWORD
               (* parameters: *) ParametersDeclaration
               (* attributes: *) FunctionTypeAttributes
               (* returns: *) ReturnsDeclaration?;

FunctionTypeAttributes = (* item: *) FunctionTypeAttribute*;

FunctionTypeAttribute = (* variant: *) INTERNAL_KEYWORD
                      | (* variant: *) EXTERNAL_KEYWORD
                      | (* variant: *) PRIVATE_KEYWORD
                      | (* variant: *) PUBLIC_KEYWORD
                      | (* variant: *) CONSTANT_KEYWORD (* Deprecated in 0.5.0 *)
                      | (* variant: *) PURE_KEYWORD (* Introduced in 0.4.16 *)
                      | (* variant: *) VIEW_KEYWORD (* Introduced in 0.4.16 *)
                      | (* variant: *) PAYABLE_KEYWORD;

MappingType = (* mapping_keyword: *) MAPPING_KEYWORD
              (* open_paren: *) OPEN_PAREN
              (* key_type: *) MappingKey
              (* equal_greater_than: *) EQUAL_GREATER_THAN
              (* value_type: *) MappingValue
              (* close_paren: *) CLOSE_PAREN;

MappingKey = (* key_type: *) MappingKeyType
             (* name: *) IDENTIFIER?; (* Introduced in 0.8.18 *)

MappingKeyType = (* variant: *) ElementaryType
               | (* variant: *) IdentifierPath;

MappingValue = (* type_name: *) TypeName
               (* name: *) IDENTIFIER?; (* Introduced in 0.8.18 *)