Topic: data type compatibility

topics > computer science > data > Group: type checking

data type
casting a variable to a different type
non-exclusive data type
object and value equivalence
structural equivalence vs. name equivalence of data types
type conversion


Two types may be compatible if they have the same name, have the same definition, share the same qualifying rights, or share the same defined operations. Type compatibility by type definition makes type checking representation dependent, but widens the range of accepted types. An alternative is compatibility of representation types, e.g., 16-bit integers.

Type compatibility may mean identical type identifiers, intersecting type attributes, or convertible types. Type compatibility may be complicated when variables belong to many types. For instance, a procedure may take any argument with a name and birthday component. (cbb 5/80)

Subtopic: type compatibility up

Quote: a constant is type compatible if it can be a value of that type; it can be compatible with many types [»clayR4_1978]
Quote: a reference type conforms with a variable if it is a reference to the mode of the variable [»bekiH_1971, OK]

Subtopic: qualifying rights up

Quote: changing the qualifying rights for an element of a data structure changes its type [»joneAK4_1976, OK]

Subtopic: mutable vs. immutable up

Quote: mutable objects are the same only if they are the same object [»liskBH2_1976, OK]

Subtopic: representation type up

Quote: a rep-type is the set of modes with the same representation; explicitly declared, includes operations

Related Topics up

Group: data type   (34 topics, 730 quotes)
Topic: casting a variable to a different type (7 items)
Topic: non-exclusive data type (16 items)
Topic: object and value equivalence (60 items)
Topic: structural equivalence vs. name equivalence of data types (30 items)
Topic: type conversion
(33 items)

Updated barberCB 5/04
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