From c1856d1f3edbc4b32be5860233dede88db16a7bb Mon Sep 17 00:00:00 2001 From: Jan Tuomi Date: Thu, 1 Jan 2026 17:36:39 +0200 Subject: Start migrating content --- content/posts/it-doesnt-mean-that.md | 42 ++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 content/posts/it-doesnt-mean-that.md (limited to 'content/posts/it-doesnt-mean-that.md') diff --git a/content/posts/it-doesnt-mean-that.md b/content/posts/it-doesnt-mean-that.md new file mode 100644 index 0000000..adf171f --- /dev/null +++ b/content/posts/it-doesnt-mean-that.md @@ -0,0 +1,42 @@ +--- +title: It doesn't mean that +date: 2024-03-31 +extra: + kind: note +--- + +A plain circle with a small dot in the center + +## When I learned my first programming language + +I learned about functions. + +A _function_ is a thing you can call. The function might then _return_ a value. + +## Then I learned about functional programming + +And learned that those words did not mean that at all. Or at least that was not their full, universal meaning. + +Those _functions_ were actually _procedures_. Or _subroutines_. A function should be mathematical and pure. A mapping from a type to another. + +_Returning_ was not optional. All functions return, explicitly or implicitly, since function application must be assigned a value. + +I learned new words too. + +_Functors_ are containers. _Monads_ are powered-up functors with useful computational context. + +## Now that I’m learning about category theory… + +…I’m learning that those words do not mean what I thought they meant, either. + +_Functions_ are apparently morphisms, or arrows, in the category of types. _Functors_ are not containers, they are morphisms between categories. They are also their own category. + +_Monads_ are — I haven’t gotten to monads yet. + +## I read that they have a Monad in philosophy + +And it means _god_. [¹](it-doesnt-mean-that#fn1) + +--- + +1. More or less. -- cgit v1.3