HTTP Server

A slightly more interesting example is an HTTP Server:

require "http/server"

server = HTTP::Server.new do |context|
  context.response.content_type = "text/plain"
  context.response.print "Hello world! The time is #{Time.local}"
end

address = server.bind_tcp 8080
puts "Listening on http://#{address}"
server.listen

The above code will make sense once you read the whole language reference, but we can already learn some things.

• You can require code defined in other files:

  require "http/server"
  

• You can define local variables without the need to specify their type:

  server = HTTP::Server.new(...)
  

• The port of the HTTP server is set by using the method bind_tcp on the object HTTP::Server (the port set to 8080).

  address = server.bind_tcp 8080
  

• You program by invoking methods (or sending messages) to objects.

  HTTP::Server.new(...)
  # ...
  Time.local
  # ...
  address = server.bind_tcp 8080
  # ...
  puts "Listening on http://#{address}"
  # ...
  server.listen
  

• You can use code blocks, or simply blocks, which are a very convenient way to reuse code and get some features from the functional world:

  HTTP::Server.new do |context|
    # ...
  end
  

• You can easily create strings with embedded content, known as string interpolation. The language comes with other syntax as well to create arrays, hashes, ranges, tuples and more:

  "Hello world! The time is #{Time.local}"