Lispy Elixir

Transcript

1. Lispy Elixir @PatrickGombert
2. Lisp crash course (LISt Processing) () ; data structure (f) ; data structure and executable code (1 2 3) ; data structure without executable code ! ; closure definition ! ; program returning 4
3. Composability ; Higher order function ! ; Function returning a function ! ; equivalent to !
4. Elixir is composable ; Higher order function ! ; Function returning a function ! equivalent to
5. Homoiconicity - Code is represented as data (everything is a list in lisp) - The resulting structure is a form of Abstract Syntax Tree (+ ; Root Node (+ ; Child of Root 1 ; Leaf Node 2) ; Leaf Node (+ ; Child of Root 3 ; Leaf Node 4)) ; Leaf Node !
6. Elixir is homocionic… ?
7. Look past syntax, you must
8. Quote This doesn’t print hello world, but why?
9. I heard you like programs in your programs
10. Elixir allows you to program while you program!
11. Homoiconic AST function arguments
12. Not quite as elegant… vs.
13. ISMETA (http://xkcd.com/917/) = =
14. ! Erlang’s Parse-Transform http://www.erlang.org/doc/apps/erts/absform.html
15. … or lisp style macros! - Compile time (like parse-transform) ! - Homoiconic AST manipulation (like parse-transform) ! - Consistent AST (!!!)
16. defmacro ! ! - all at compile time - quoted arguments - returning ASTs for the evaluation in the current module
20. List Comprehensions
21. And without the commas
22. It’s macros (almost) all the way down Turtle = Macro
23. Erm… umm…
24. ! So of course…
26. Slow down cowboy It’s a context switch between compile & run times
27. Macro bootstrap step https://github.com/elixir-lang/elixir/blob/master/lib/elixir/ src/elixir_bootstrap.erl
28. Splicing
29. Hygiene Note: Elixir is immutable so the rebinding is in the local scope
30. Thanks! @PatrickGombert