type Fruit is (Banana, Orange, Pear);
Choice : Fruit := Banana;
A character type is an enumeration that includes a character literal:
type Roman_Numeral is
('I', 'V', 'X', 'L', 'C', 'D', 'M', Unknown);`
These are the “bit fiddling” types. They have logical operators, too, such as xor, and they “wrap around” at the upper bound, to 0 again.
type Bits is mod 2**24;
L : Bits := 2#00001000_01010000_11001100# or 7;
A floating point type is characterised by its (decimal) digits which state the minimal precision requested.
type Distance is digits 8;
Earth : Distance := 40_075.017;
A fixed point type definition specifies a delta, and a range. Together, they describe how precisely real values should be approximated as they are represented by powers of two, not using floating point hardware.
Shoe_Ounce : constant := 2.54 / 64.0;
type Thickness is delta Shoe_Ounce range 0.00 .....
Decimal fixed point types are typically used in accounting. They are characterised by both a delta and a number of decimal digits. Their arithmetical operations reflect the rules of accounting.
type Money is delta 0.001 digits 10;
Oil_Price : Money := 56.402;
Loss : Money := 0.002 / 3; -- ...
