Logic
Programming is an interesting way to solving problems it’s based on the clojure
core.logic namespace, it kind of solves the problems backwards, as described in
the lecture, and it’s kind of like magic.
In logical
programming you tell the program the basic rules of the problem and an initial
state, and the program will find the solution to the problem without much work
required from us.
When we
code in logical programming, our goal is to match both sides of our expression to
try and get a number of possible solutions. We can limit the number of solution
provided by writing run followed by a number of maximum number of solution we
want to get in return, if the number of solutions is less than the number we
specified, we will just get that number. If we use the run* form, this means we
will get all the possible solutions to the bounding of our condition. This can
be dangerous if we have infinite number of possible solutions.
Expressions
in logical programming don’t return true or false, instead, they return succeed
or fail if the expression is able to bind our query to our goal.
Some other functions
make it possible to bind queries to our goals in parallel ways which is similar
to creating “parallel universes”.
Relationships
can be created using this schema, creating databases it’s very simple and it
will make solution solving very easy. When denoting relationships, an “o” must
be added at the end of the name. Example “mothero”.
There are
other ways to matching expression, a very useful way is using the matche pattern,
which is a version of conde and makes this kind of code much more clear and
concise.
Functions
like map can be used in logical programming and work pretty much like they do
in clojure and are used to match patterns.
There are
other ways for matching patterns, such as using conde, condu, and condo, these
types of conditionals work in parallel to try and match conditions to its
bindings in a proper way.
Logical
Programming is a very powerful tool, but can be mind-bending when trying to
fully understand it.
