# Notes (OFVB 03/31): Case by Case

Okay, so since copy-pasting into a REPL is no fun, I’m going to quickly flip forward to the section “Loading a Program from a File”:

Save the file in same directory (folder) as you enter OCaml from, under the name lists.ml:

# #use "lists.ml";;

We can then tell OCaml to use the contents of that file like this: It is exactly the same as typing it in manually […] Errors and warnings will be reported as usual. Note that the #use command is not part of the OCaml language for expressions – it is just a command we are giving to OCaml.

One thing to add is that unlike in Haskell, we can’t put our type signatures in the same file. Apparently, there’s a separate “interface file” with a .mli extension, but I won’t worry about that yet.

# Questions

see case.ml

## 4

Easier to read pattern matching, since doesn’t require nested if statements.

## 5

Evaluates to 5