2.2.3) Structures

Structures are compound types. Both input and output structures are treated in this section. Follows the description of all the structures:

Structure	Description	Examples
record id:type ... id:type end	Record structure This is a fixed length multi-type structure	record a:nat b:real end {23 .345}
list of type	List structure This is a variable length single-type structure	list of nat {2 3 4 6 7 8 3 4 2 3} {3 4}
array(nat) of type	Array structure This is a fixed length single-type structure	array(5) of nat {1 2 3 4 5} but not {56 23 45 23}
case id of nat id:type ... nat id:type else id:type end	Case structure In dependence of the first id, it can have different types Else line is optional	case a of 1 b:nat c:real end {1 23} {2 .345}

Although input and output structures are syntactically identical, semantically they are not. Moreover, input types cannot be used inside output structures and vice versa.