Types

type = primitive-type | structure-type | union-type | empty-type ;

type-prefix = "type" identifier [generic-list] ;

generic-list-r = identifier | identifier "," generic-list-r ;
generic-list = "(" generic-list-r ")" ;

Empty types

An empty type is an abstraction on the concept of “nothing”. A variable with an empty type always hold a value representing “nothing”.

Value of empty types are not compatible between each other.

empty-type = type-prefix ;

Primitive types

The following types are known as primitive types:

• int (64-bit integer)
• float (64-bit double precision floating point number)
• bool

primitive-type = "int" | "float" | "bool" ;

Structure types

Structure types are records that contain one or more fields. Each field is denoted by an identifier that is unique to the record, and a type.

structure-type = type-prefix "=" "{" field-list "}" ;

field-list = field
           | field ";" field-list ;

field = identifier ":" type-identifier ;

Union Types

Union types denote an abstract type representing the logical union of all the specified types – a value with a type that is contained within an union can fit in a variable of this union type.

union-type = type-prefix "=" type-list ;

type-list = type-identifier
          | type-identifier "|" type-list ;