24th November
Built in function: len
Getting on this interpreter journey has been refreshing, I was feeling uninspired about writing code for the last year or so. The last couple of months have flipped it, and I can't wait to get to my desk.
I've digressed.
So builtins are interesting. They are like regular function but defined within the
evaluator. In other languages you could use a for loop to get the length but since
we have not defined loops this would be the only way to get a length of a string.
This is interesting because, if you consider things you use to make your code useful
like listening to a port server.ListenAndServe. You are using a method that intern uses an interface
net to communicate to underlying network i/o on your computer. My point is, if you had
to build this interface yourself the language wouldn't be very useful (for most people).
Although, len is a very simple builtin function. It was interesting to know
how one would add it to a programming language.