1/31/15

Tuple, Set, Entity, Object, State.

What are differencies between Tuples, Sets, Entities, States & Objects?

in a context of this blog:


Tuple.

Tuples are ordered n-values, for example:
- 0-tuple: (),
- 1-tuples: (1), (a), (c), ...
- pairs (a,b), (3,a), ...
- triples (a,b,c), (1,2,z), ...
- ...


Set.

Sets are unordered n-values, for example:
- empty set: {},
- nonempty sets: { 1, (a,b), {a} }, { a }, { 1, 2 }, ...

i think i remember that every set, including empty set, contains an empty set.


Entity.

'entity' is an 'unordered tuple set', for example a 'table' with 'tuples' in the database.

it is unordered, but can be sorted of course, with any of the 'sorting criteria'.

'metadata' or 'data describing data' can be one of the tuples in this a set, can exist as a 'separate tuple-entity' associated with another 'entity', or might be not present at all.


State.

state is value of all of object's variables concatenated, for example.

there are other definitions as well, many of them valid.

state is not a tuple, but always has properties of a tuple.

one or many a tuple can be part of a state.


Object.

object is state with methods that can change object's state.

objects have lifecycles - series of states that objects have at given moments in time.

transitions between states in lifecycles can be modelled using finite state automatons.


see also if You wish or need, ... : Tuple Data Type & Syntax.

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