Programming in hack

Programming in Hack

Alejandro Marcu

Dutch PHP Conference 2016

2

Started programming Logo at 8 years old

Then moved to Basic, Turbo Pascal, C++, Java

2001 – 2004 Various programming jobs in Argentina

2004 – 2008: TopCoder 2009 – 2015: Facebook

Alejandro Marcu

3

1. Introduction

2. Hack Types

3. Collections

4. Async

5. XHP

6. Hack Codegen

What You Will Learn Today

Introduction

5

HHVM history

2007 - Hackathon project: convert PHP to c++

2009 – HipHop (HPHPc) in prod in Facebook

2010 – Open sourced HipHop for PHP

2010 – Started the HHVM project

2013 – HHVM in prod in Facebook

2013 – HHVM open sourced

6

In 2014 Wikipedia migrated to HHVM:

CPU load went from 50% to 10%

Mean page save time went 6s to 3s

Average page load time went from 1.3s to 0.9s

PHP 7 performance is close to HHVM

Example of migration to HHVM

7

Started in 2012 as “strict-mode” project

Grew to be much more than that

Open sourced in 2014

As of now, HHVM is the only execution engine that

runs Hack

Totally interoperable with PHP, allowing for a gradual

migration

Hack

8

Analyzes Hack programs statically

Monitors files changes in the background

Extremely fast, even in huge code bases

Can even be used by IDEs to autocomplete code

Typechecker

Typechecker

hacklang.org/tutorial/

10

Type annotations Collections Async XHP Attributes Constructor parameter

Promotion Enums Generics

Hack only features

Operators Lambda Null safe XHP attribute access Pipe operator

Shapes Trait and interfaces

requirements Type aliases

11

References Global statements Top level code Variable variables Dynamic properties Pseudo-functions

isset empty Unset

goto Etc..

Unsupported features in Hack

12

<?hh //strict Type annotations required Can’t call PHP No top level code No references

<?hh // partial or<?hh

The following is allowed but not checked:• Calls to PHP• Top level code• References

Type annotations not required but checked if present

<?hh // decl Not checked at all Functions and classes are indexed Use it only as the first step to migrate to

Hack

Typechecker modes

Type annotations

14

Types

Primitive types bool int float string array resource

Combined primitive types num (int or float) arraykey (int or string)

Object types Name of classes or interfaces

Return types

void can be used only as a return type

Parameters

Nullable parameters

Local variables

Class attributes

Constructor argument promotion

Generics

Arrays with generics

Collections

Vector0-indexed list

MapKeys: int or str.Values: anything

SetUnique elements

Collections overview

Vector

Immutability

37

Single thread blocking

Single thread non-blocking

Multithread

Threads

Single Thread blocking example

Async example

44

Use the keyword async before function The return type must be Awaitable<…> Call async from async using await Call async from non-async using HH\Asio\join Make parallel calls using helpers in HH\Asio\

(such as v,vm,m,mf, etc.)

Async

46

What is XHP?

XHP is used to generate HTML in PHP or Hack No templating No string concatenating

Represent HTML as a tree of objects Familiar XML syntax Secure Strong validations Extensible

Hello World

composer.json

xhp.php

Hello World

Adding children

Custom class definition

Inheriting and transferring attributes

Async components

53

XHP parser transforms it into regular Hack code:

XHP class names are replaced:

First char colon is replaced with xhp_

Other colons are replaced with two underscores

Hyphens are replaced with an underscore

E.g. :ui:nav:header is replaced with xhp_ui__nav__header

XHP internals

54

XHP tags are replaced with constructors. E.g.

will be replaced with:

XHP internals

Hack Codegen

56

Why code generation?

Code generation: writing code that writes code

Higher level of abstraction

Generate boilerplate code

Generate code from almost static data in database

Replace usage of __call

57

Easy to create files, functions, classes, methods, arrays, collections, etc

Support for partially generated files Files can be signed No string concatenation No need to indent or add spaces https://github.com/facebook/hack-codegen/ Composer: require facebook/hack-codegen

Hack Codegen

https://github.com/facebook/hack-codegen/

Hack Codegen example

Hack Codegen example output

ORM code generation

Learning Resources

65

Learning resources

http://hacklang.org/ : installation, tutorial, docs

“Hack & HHVM” book

http://hacklang.org/

Contact Information

[email protected]

/alejandro.marcu

/alejandromarcu

@AlejandroMarcu

/in/alejandromarcu

Programming in hack

Software

Transcript of Programming in hack