Class: Walnut::Shell

Inherits:
Object
  • Object
show all
Defined in:
lib/walnut/shell.rb

Overview

A simple shell.

Instance Method Summary collapse

Constructor Details

#initialize(&block) ⇒ Shell

Constructor.



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# File 'lib/walnut/shell.rb', line 11

def initialize(&block)
  # Set the default config to the global.
  @config = Walnut.config.dup
  
  # Start with the global hooks.
  events = Walnut.ev.dup
  define_singleton_method(:ev) { events }

  instance_exec(@config, &block) if block_given?
  
end

Instance Method Details

#[](key) ⇒ Object

A shortcut to the configuration

Parameters:

  • key (#to_s) —

    The configuration key you are looking for

Returns:

  • (Object) —

    The object that the configuration key points to



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# File 'lib/walnut/shell.rb', line 37

def [](key)
  @config.send(key.to_s)
end

#[]=(key, value) ⇒ Object

A shortcut to assign configuration values.

Parameters:

  • key (#to_s) —

    The key you are looking up in the configuration.

  • value (Object) —

    The new value for the key in the configuration.

Returns:

  • (Object) —

    The value passed to be assigned.



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# File 'lib/walnut/shell.rb', line 48

def []=(key,value)
  @config.send(key.to_s << "=", value)
end

#configure {|@config| ... } ⇒ Object

Configure the shell.

Yields:



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# File 'lib/walnut/shell.rb', line 25

def configure

  yield @config if block_given?

end

#crack(input = @config[:input].interface, output = @config[:output].interface) ⇒ Walnut::Shell

Begin a session, crack being a cutesy way to allude to the name of the project.

Parameters:

  • input (IO) (defaults to: @config[:input].interface) —

    This object should at least implement the interface for Input.

  • output (IO) (defaults to: @config[:output].interface) —

    This object should at least implement the interface for Output.

Returns:



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# File 'lib/walnut/shell.rb', line 59

def crack(input=@config[:input].interface, output=@config[:output].interface)
  
  if input  then @config[:input].interface  = input  end
  if output then @config[:output].interface = output end

  input  ||= Walnut[:input].interface
  output ||= Walnut[:output].interface
  ev.nut_throw :cracking
  loop do
    ev.nut_throw :before_read
    text = input.gets
    
    if input.eof?
      ev.nut_throw :eof, self

      # This has to be unset in a hook to recover from the EOF
      break if input.eof?
    end
    
    ev.nut_throw :after_read, text
    
    ev.nut_throw :before_parse, text 
    ast = nil #Parse -- ast == Abstract Syntax Tree. This is basically dependant on how the parser handles it.
              #      -- There is no definite interface for this because of the vast differences in parsers/lexers.
    ev.nut_throw :after_parse, ast
  end

  # Cute after session hook name.
  Walnut.ev.nut_throw :scrambled
end