Next: , Previous: Type Definition, Up: Data Types

6.2.2 Ordinal Types

An ordinal type is one that can be mapped to a range of whole numbers. It includes integer types, character types, enumerated types and subrange types of them.

A character type is represented by the intrinsic type Char which can hold elements of the operating system's character set (usually ASCII). Conversion between character types and integer types is possible with the intrinsic functions Ord and Chr.

An enumerated type defines a range of elements which are referred to by identifiers. Conversion from enumerated types to integer types is possible with the intrinsic function Ord. Conversion from integer to ordinal types is only possible by type-casting or using the extended form of Succ.

       Foo: Char;       { foo can hold a character }
       Num: '0' .. '9'; { Can hold decimal digits, is a subrange type of Char }
       Day: (Monday, Tuesday, Wednesday, Thursday,
             Friday, Saturday, Sunday);  { Can hold weekdays }

See also

Ord, Chr, Type Casts