Learning new programming languages can be difficult. One way that helps me is to write a bunch of different programs (or rewrite old stuff from other languages) as a way to get more practice using the various parts of the language. It helps to have something I'm familiar with, but also has enough challenge where I can really dig into the strengths or inconveniences of a given language.

A Brainfuck interpreter is - for me - a great program to write as it includes enough pitfalls that you can easily get stuck, but is also simple enough that you can do it in a couple of hours, worst case.

Brainfuck is a Turing-complete, esoteric language created by Urban Müller in 1993. Building off of Corrado Böhm's P'' ("P double-prime") language, Brainfuck allows for easy input/output with the operators , and . respectively. Feel free to read more about Brainfuck here

• R
• Kotlin
• F#
• C
• D
• Zig
• PowerShell
• VBA
• VBScript
• PHP
• Lua
• Elixir
• Haskell
• COBOL
• FORTRAN
• Assembly

• Python
  • N/A
• Rust
  • N/A
• JavaScript
  • N/A
• Ruby
  • Really easy and nice to use. Though, I do find Array initialization to be kinda wonky
• Go
  • The whole concept of "runes"
  • When reading data from a file it will give you the data how it is represented in memory. So reading "AAA" from a file and iterating over it will yield "656565". Meaning you often have to convert things between strings, runes, etc
• Bash
  • Bash has always been a fun, cryptic, and wizardly experience when writing it. So I always like trying weird stuff like this to learn new tricks.
  • Arithmetic Comparison (i.e. the (()) syntax to do stuff like (( thing < 69 ))) always trips me up and I often forget about it
• C++
  • Wayyyy easier than I expected it to be. I'm sure more complicated things would get annoying, but this wasn't nearly as bad as I was prepared for
• Perl
  • Feels like a weird lovechild of Python and Bash. Some things are easy and high level, but the required symbols before variable names is really annoying

Here is a list of things that you have to do to create an interpreter for Brainfuck. This also doubles as a list of all the things you end up learning for every new language

• Read file contents into a variable (usually a string, but sometimes a byte array. Really just anything that is indexed and you can iterate over)
• Declare an indexed array of a fixed size
• Declare an indexed array of variable size
• Start a WHILE loop
• Get length of a string
• SWITCH statement (or MATCH, or an IF/ELSE ladder, etc)
• Change value in array
• Append value to the end of an array
• Remove value from the end of an array
• Get value at the end of an array (You'd be surprised how many languages do not support negative array indexing)
• Keyboard input
• Converting input (often a string) into the decimal representation for that given ASCII value (e.g. A -> 65)
• Converting decimal to ASCII for printing (e.g. 65 -> A)
• Printing to the console
• Does the language have a simple +=1 syntax, or do you have to do the long version?
• Does the language have a simple NOT operator like ! or not? (This is why I do if !loop at the bottom of my WHILE loops rather than switch the logic and do if loop)