CanBeDomainUnit

Value type CanBeDomainUnit

definition

CanBeDomainUnit is the group of value types that can be used for a domain unit.

The applies to sections of many operators and functions refer to this group, for arguments that need to be a domain unit or a relation towards a domain unit.

value types

The group consists of the value types marked in the Can Be Domain Unit column of the value type table:

• uint8, uint16, uint32, uint64: unsigned integers, the most commonly used value types for one-dimensional (table) domains
• int8, int16, int32, int64: signed integers
• bool, uint2, uint4: sub byte unsigned integers, for domains with a very limited set of elements
• spoint, wpoint, ipoint, upoint: point value types with integer coordinates, used for two-dimensional (raster) domains

Furthermore the void value type is in this group; it is used as the (implicit) domain unit of a parameter, with exactly one element.

why

A domain unit defines the set of entries of its attributes, so its value type must be countable, with a defined range of values that maps one-to-one to the row (or row and column) numbers of the domain.

Units with a float32, float64, fpoint, dpoint or string value type are not countable and can therefore not be used as domain unit.

see also

• domain unit
• one dimensional domain
• two dimensional domain
• cardinality