1.15: 6.12: adda/oop/multi-object modifications:
. the object notation: "( object`operation )
is saying that the given object is modifying itself;
whereas, if no modification was expected,
the preferred syntax would be "( operation(object) ).
Showing posts with label polymorphtype. Show all posts
Showing posts with label polymorphtype. Show all posts
2014-06-12
2013-12-27
subtypes of values vs addresses #terminology
12.10: mis.adda/oop/terminology/subtypes of values vs addresses:
. I'm misusing the term "subtype"?
let's review,
2010/04/polymorphic-vs-evolutionary-subtyping.html
2012/02/def-supertype-supratype-surtype.html
2012/10/infratypes-of-surtypes-phyla-of-taxa.html
# for passing a value in:
. if the actual is a subrange of the formal,
then it will fit, and the actual is
serving both types, and that's what a subtype is .
. if the actual is a
constant version of the formal's type,
no changes are needed so input is accepted,
and constant T is a subtype of T here .
# for passing a value out:
. if the actual is a subrange of the formal,
the formal is saying
"I might send out a large number"
and the actual is saying
"I can't handle large numbers";
therefore access to subrange of T
is not a subtype of access to T .
. if the actual is
a constant version of the formal
the constant fails to accept any of the output;
therefore access to constant T
is not a subtype of access to T .
. after reading notes on terminology
I decided on yet another revision to that:
"surtype" is the system's typeclass
(pointer, valuetype, subprogram, aggregate, ...);
because, a surtype can classify
every object found in a programming environment .
. a polymorphic typeclass like number.type
is an example of a "polymorphtype" .
. the types {N,Z,Q,C,R}
are all the "morphtypes" of number;
"morphsubtypes" are constrained subtypes of morphtypes;
"infratypes" are implementations of a morphtype,
eg, the machine type Z32 (32-bit integer)
may implement a subrange of morphtype Z .
. I'm misusing the term "subtype"?
let's review,
2010/04/polymorphic-vs-evolutionary-subtyping.html
2012/02/def-supertype-supratype-surtype.html
2012/10/infratypes-of-surtypes-phyla-of-taxa.html
"you mean that N is a subset of Z,so, "subtype" is the right word sometimes .
but then that implies Z is a subtype of N?
that depends on the direction:
you can represent any N value with a Z,
but if I need the address to an N,
a Z is no substitute because it
doesn't enforce my range constraint ."
# for passing a value in:
. if the actual is a subrange of the formal,
then it will fit, and the actual is
serving both types, and that's what a subtype is .
. if the actual is a
constant version of the formal's type,
no changes are needed so input is accepted,
and constant T is a subtype of T here .
# for passing a value out:
. if the actual is a subrange of the formal,
the formal is saying
"I might send out a large number"
and the actual is saying
"I can't handle large numbers";
therefore access to subrange of T
is not a subtype of access to T .
. if the actual is
a constant version of the formal
the constant fails to accept any of the output;
therefore access to constant T
is not a subtype of access to T .
. after reading notes on terminology
I decided on yet another revision to that:
"surtype" is the system's typeclass
(pointer, valuetype, subprogram, aggregate, ...);
because, a surtype can classify
every object found in a programming environment .
. a polymorphic typeclass like number.type
is an example of a "polymorphtype" .
. the types {N,Z,Q,C,R}
are all the "morphtypes" of number;
"morphsubtypes" are constrained subtypes of morphtypes;
"infratypes" are implementations of a morphtype,
eg, the machine type Z32 (32-bit integer)
may implement a subrange of morphtype Z .
Labels:
adda,
infratype,
morphsubtypes,
morphtype,
oop,
polymorphtype,
subtype,
surtype,
terminology,
type class
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