fp-in-erlang/notes.org

Org-mode test

(require 'org-tempo) (require 'ob-erlang) (org-babel-do-load-languages 'org-babel-load-languages '((erlang . t) (shell . t)))

start() ->
	io:format("hello world").

Start REPL

erl

Eshell V10.3.5.9  (abort with ^G)
1> *** Terminating erlang (nonode@nohost)

Language elements

Arithmetic

3+4.

Operations

• +,-,*,/
• div (division without remainder)
• rem (remainder of whole number division)
-

Lists

A = [2,3,4].
hd(A).

Lambda expressions

(fun (X) -> X+X end)(99).

Primitive data types

1. Numbers
2. Integer - Bignums, arbitrarily large and full precision
3. Numbers with different base: 2#10010011 for example is binary.
4. Atoms
5. written with small letter in the first place: foo
6. written in single quotes: 'i am an atom'
7. compare: ==
8. order: >, <
9. special atoms: true, false
10. Booleans:
11. true
12. false
13. Tuples:
14. pieces of data, put together in curly braces: {1,2,3,{4,5}}
15. often data is tagged tuples: {<atom describing the tuple>, <payload>} for example: {rectangle, {0, 0}, {2, 3}}
16. data can be heterogenous
17. immutable, must be built in one go
18. Lists:
19. in square brackets: [elem1, elems]
20. data can be heterogenous, often is homogenous
21. append operation: ++
22. length: length/1
23. Strings:
24. list of characters
25. characters are numbers
26. ASCII code for a character: $<char>
27. Functions:
28. anonymous function syntax: fun (<args> ...) -> <exprs> ... end