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Comment by brudgers | Hacker News Reader

Prolog, SQL, or other logic programming languages...as mentioned in the linked C2 entry.

Right, but these languages are declarative.

Sorry. I guess I don't see how a goal oriented language would work without declaring the goal and declaring the conditions under which it must be achieved.

An imperative goal oriented language can be implemented as a staged language using lambdas. The first stage answers the question, "What are the subgoals?" The second stage applies a subgoal to a candidate solution.

Logic-programming style control flow can be implemented on top of these two primitives.

Yes, I agree. But in the article I shared, they say that this goal-oriented language would be somehow "imperative" in the sense that you would be telling to the computer concrete things to do, just from a (much) higher abstraction level.

The C2 page is a wiki (the orginal). The page contains several viewpoints by different authors. Among them is the view that the division into a 2x2 table is incomplete/incorrect/of-limited-utility. For me, the relationship of declarative languages to the ordinary usage of "goal" is much stronger (for me at least) than the vague terms used to create the 2x2 table. To put it another way, I find the premise dubious. For me, it is useful to keep in mind the truth table of conditional statements in modal logic:

   a -> b
           b = T     b = F
         +--------+--------+
   a = T |   T    |    F   |
         +--------+--------+
   a = F |   T    |    T   |
         +--------+--------+

For me, the statement about there being some fourth category is trivially true because the division into two categories is false.

Did you read the article the poster is reffering to, though?

It specifically mentions that the kind of "missing paradigm" looked for is not one of the declarative ones we currently have (SQL, Prolog, etc) because those fall into the Evaluate + Consequent combo.

So, he gives 3 paradigms:

FunctionalProgramming -> Evaluate + Mechanism (list of instructions)

ImperativeProgramming -> Execute + Mechanism

LogicProgramming/ConstraintProgramming -> Evaluate + Consequent (i.e. towards a consequent (result) based on constraints) [this is where declarative falls).

So, the "goals oriented" language he defines as the missing: Execute + Consequent pair.

Yes. And the Hacker News guidelines.

I would expect something more substantial for my "several paragraphs with summary and references" response than "the HN guidelines say to not question whether another has read TFA" then...

Not going to feed you.

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