asterite

abstract class Observer(T)
  abstract def notify(obj : T)
end

module Observable(T)
  def add_observer(observer : Observer(T))
    observers = @observers ||= [] of Observer(T)
    observers << observer
  end

asterite

require "benchmark"

def foo(&block)
  bar(&block)
end

def bar
  yield
end

asterite

def with_pipe
  read, write = IO.pipe
  yield read, write
ensure
  read.close if read rescue nil
  write.close if write rescue nil
end

with_pipe do |read, write|
  thread = Thread.new do

asterite

require "json"

class Object
  macro def_find_by_name
    {{:macro.id}} def self.find_by_name(name) : {{@type.name.id}}.class
      case name
        \{% for subclass in {{@type.name.id}}.all_subclasses %}
          when \{{subclass.name}}
            \{{subclass.name.id}}
        \{% end %}

asterite

require "json"

abstract class Plugin
  macro def self.find_by_name(name) : Plugin.class
    case name
      {% for subclass in Plugin.all_subclasses %}
        when {{subclass.name}}
          {{subclass.name.id}}
      {% end %}
    else

asterite

require "json"

abstract class Plugin
  ALL = {} of String => Plugin.class

  macro inherited
    ALL[{{@type.name}}] = {{@type.name.id}}
  end
end

asterite

def foo(x : T)
  T::Baz
end

foo(1 || 1.5)

asterite

/usr/include/arpa/ftp.h:#define ERROR		5	/* permanent negative completion */
/usr/include/arpa/telnet.h:#define	EL	248		/* erase the current line */
/usr/include/arpa/telnet.h:#define	EC	247		/* erase the current character */
/usr/include/arpa/telnet.h:#define EOR     239             /* end of record (transparent mode) */
/usr/include/arpa/tftp.h:#define	ERROR	05			/* error code */
/usr/include/arpa/tftp.h:#define	EUNDEF		0		/* not defined */
/usr/include/arpa/tftp.h:#define	ENOTFOUND	1		/* file not found */
/usr/include/arpa/tftp.h:#define	EACCESS		2		/* access violation */
/usr/include/arpa/tftp.h:#define	ENOSPACE	3		/* disk full or allocation exceeded */
/usr/include/arpa/tftp.h:#define	EBADOP		4		/* illegal TFTP operation */

asterite

class Tuple
  def +(other)
    Tuple.new *self, *other
  end
end

a = {1, 'a'}
b = {"hey", 1.5}
c = a + b
puts c

asterite

struct ThreadSafe(T)
  def initialize(@obj : T)
    @mutex = Mutex.new
  end

  macro method_missing(name, args, block)
    @mutex.synchronize do
      @obj.{{name.id}}({{*args}}) {{block}}
    end
  end