Constructed Types and subtyping

[Bart Bogaerts]

Constructed types and subtyping is unpredictable The intended behavior should be * declared * documented * implemented

see for example the weird behavior in the attachment

[Bart Bogaerts]

Also, in cases that are not handled, the exceptions should be more clear:

not "Addition of domain elements to a constructed sort is not yet implemented." but "subtypes of constructed types are not supported" or something like that

[Bart Bogaerts]

other related remark, now constructed types can be subtypes of string...

[JoD]

Related to https://bitbucket.org/krr/idp/issue/472/no-type-check-for-constructed-subtypes-of.

[JoD]

Solved by not allowing any constructed type to be a subtype, and only allowing other types to be declared as a subtype of a constructed type. E.g.:

type T isa T2 constructed from {...}

type T constructed from {...} contains T2

type T constructed from {...} | type T2 contains T

are NOT allowed, but:

type T constructed from {...} | type T2 isa T

IS allowed.

[JoD]

Remark: fix includes not enabling "isa" or "contains" in conjunction with "constructed from" by the parser. So you will get a parsing error in those cases. An "not allowed to use constructed types as subtype"-error will be thrown in the case of "T2 contains ConstrType".

[JoD]

resolved by 19ff2dc1456118bb456e2b233ea6dbed5e3e8cd3