aoc2020

Advent of Code 2020, in Julia lang this year

Updating Julia to new version on Mac

Just download and run the latest binary from https://julialang.org/downloads/ and it will ask if you want to replace older version (if such exists)

Package management

Pkg package manager is used. It is centered around environments:

Independent sets of packages that can be local to an indivdual project or shared and selected by name.

The exact set of packages and versions in an environment is captured in a manifest file which can be checked into a project repository and tracked in version control.

• Project
• Environment
  • Defines which packages that are available to a piece of code
• Module
• Package
  • A module that can be refered to in a package registry with a globally unique version (UUID)

Package mangaement will need more reading

Nice, cosy feeling

Julia is one-based! Why on earth did we do zero-based in the other languaes?

Classes are called Composite Types

Just create a struct or a mutable struct. A struct is imutable, hence the mutable struct.

Variable Scope

Make sure to do anything usefull inside a function. Do not use global variables.

Regexp

regexp are denoted by

r"<some regexp>"

Stream operations

map, reduce, mapreduce etc are rally powerful to run on collections

Views

Really nice way to be able to work on an array as a view of a database table (kind of). a = [1,2,3,4,5] v = @view a[2:4] -> v = [2,3,4]