My intention is simply to share my learning experience with category theory by using the built-in documentation and
testing faculties that Rust provides. I will also conduct screen casts to explore each implementation so that I can
make sure that what I commit to the crate is logical. I hope that by doing this, others can apply this knowledge to
what they do at
$WORK in C++, Go, Java, etc.
|CTFP Chapter||Topic||Articles||Lecture Videos||Notes|
|1||Introduction||Category: The Essence of Composition||Motivation, What is a category?||See |
Is the world-wide web a category in any sense? Are links morphisms?
I would say yes. We know that web pages have something akin to an identity morphism: its URI/URL. And links between pages may be composable (a link from site A to B can, through the redirect protocol, map to a third side C).
Update: After a conversation with a few people in the #categorytheory channel on FP Slack, care must be
taken to specify that we mean the morphism that defines the whole REST or HATEOAS command cycle for a link in this example; not the
links themselves. So the correct answer to Bartosz's question depends on what we mean by what
Is Facebook a category, with people as objects and friendships as morphisms?
Not really, because social relationships cannot always compose. Friend C, friend of B, is not necessarily friend of A.
When is a directed graph a category?
A DAG would classify as a category when a graph G has vertices V and edges E such that:
- all paths in the graph can be concatenated
- each V has an E that loops back to itself (so that it satisfies identity)
Composition is the heart of categorical computation.
Identity is a unit under composition.