diff options
Diffstat (limited to 'hack.html.markdown')
| -rw-r--r-- | hack.html.markdown | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/hack.html.markdown b/hack.html.markdown index 95fd9b52..89147dbc 100644 --- a/hack.html.markdown +++ b/hack.html.markdown @@ -64,7 +64,7 @@ namespace LearnHackinYMinutes { function demo_hack_types(): void { - // Hack has five primitive types: bool, int, float, string, and null + // Hack has five primitive types: bool, int, float, string, and null. $is_helpful = true; // bool $int_value = 10; // int $precise_value = 2.0; // float @@ -106,6 +106,12 @@ namespace LearnHackinYMinutes { Delete = 'D'; } + // In contrast, an enum class can be of any value type! + enum class Random : mixed { + int X = 42; + string S = 'foo'; + } + /* ================================== * HACK ARRAYS * ================================== @@ -140,8 +146,8 @@ namespace LearnHackinYMinutes { * ================================== */ - // The Hack Standard Library is a set of functions and classes for the Hack language - // Imports are ideally at the top of your file but are placed here for instruction purposes + // The Hack Standard Library is a set of functions and classes for the Hack language. + // Namespace use declarations are ideally at the top of your file but are placed here for instruction purposes. use namespace HH\Lib\C; // the `C` library operates on containers (like Hack Arrays) use namespace HH\Lib\Str; // The `Str` library operates on strings @@ -154,7 +160,8 @@ namespace LearnHackinYMinutes { C\contains($letters, 'c'); // checks for a value; returns 'true' C\contains($colors, 'purple'); // checks for a value; returns 'false' - C\contains($alphabet, 'a'); // checks for a value; returns 'true' + C\contains_key($alphabet, 'a'); // checks for a key; returns 'true' + C\contains($alphabet, 'd'); // checks for a value; returns 'false' Str\length("foo"); // returns `3` Str\join(vec['foo', 'bar', 'baz'], '!'); // returns `foo!bar!baz` @@ -184,7 +191,9 @@ namespace LearnHackinYMinutes { // Functions are defined globally. // When a function is defined in a class, we refer to the function as a method. - // Functions have return types (here: `int`) and must return a type or nothing (`void`). + // Functions have return types (here: `int`) and must return a value of + // that type or return no value when a void return type annotation was used. + function add_one(int $x): int { return $x + 1; } @@ -217,9 +226,9 @@ namespace LearnHackinYMinutes { // As another example, `__Memoize` caches the result of a function. <<__Memoize>> - function do_expensive_task(): ?string { - // return file_get_contents('http://hacklang.org'); - return "dynamic string with contents from hacklang.org"; + async function do_expensive_task(): Awaitable<string> { + $site_contents = await \HH\Asio\curl_exec("http://hacklang.org"); + return $site_contents; } /* ================================== @@ -319,7 +328,7 @@ namespace LearnHackinYMinutes { * ================================== */ - // A class can implement a set of capabilities via an interface. + // A class can implement a set of requirements via an interface. // An interface is a set of method declarations and constants. interface Plane { @@ -336,10 +345,9 @@ namespace LearnHackinYMinutes { // A trait defines properties and method declarations. // Traits are recommended when abstracting code for reuse. // Traits are included in code via the `use` keyword. - // `use` allows for other includes, like namespaces, classes, and functions (and more)! trait Airplane { - // Like other languages, classes are extended, and interfaces are implemented. + // Introduce a class or interface requirement with the following syntax: require extends Machine; // abstract class require implements Plane; // interface |