Class: Multimethod::Table

Inherits:
Object
  • Object
show all
Defined in:
lib/multimethod/table.rb

Constant Summary collapse

@@instance = 
nil
@@hook_var = 
:@@__multimethods
@@match_def = 
/^\s*def\s+(\w+)([(](.*)[)])?/

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*opts) ⇒ Table

Returns a new instance of Table.



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# File 'lib/multimethod/table.rb', line 14

def initialize(*opts)
  @multimethod_by_name = { }
  @multimethod = [ ]

  # Type name lookup cache
  @name_to_object = { }
end

Instance Attribute Details

#method ⇒ Object

Returns the value of attribute method.



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# File 'lib/multimethod/table.rb', line 13

def method
  @method
end

Class Method Details

.instance ⇒ Object 



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# File 'lib/multimethod/table.rb', line 5

def self.instance
  # THREAD CRITICAL BEGIN
  @@instance ||= self.new
  # TRREAD CRITICAL END
end

Instance Method Details

#dispatch(name, rcvr, args) ⇒ Object

Interface to code generated by #install_dispatch.



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# File 'lib/multimethod/table.rb', line 114

def dispatch(name, rcvr, args)
  unless mm = @multimethod_by_name[name]
    raise NameError, 'No method for multmethod #{name}' unless mm
  end
  mm.dispatch(rcvr, args)
end

#find_method(x) ⇒ Object 



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# File 'lib/multimethod/table.rb', line 72

def find_method(x)
  case x
  when String
    signature = Signature.new(:string => x)
  when Method
    signature = x.signature
  end

  x = @multimethod.select{|mm| mm.matches_signature(signature)}
  # $stderr.puts "find_method(#{x}) => #{x.inspect}"
  x = x.collect{|mm| mm.find_method(signature)}.flatten

  # $stderr.puts "find_method(#{x}) => #{x.inspect}"
  x
end

#find_multimethod(x) ⇒ Object 



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# File 'lib/multimethod/table.rb', line 58

def find_multimethod(x)
  case x
  when String
    signature = Signature.new(:string => x)
    when Method
    signature = x.signature
  end

  x = @multimethod.select{|mm| mm.matches_signature(signature)}

  x
end

#install_method(mod, body, file = nil, line = nil) ⇒ Object

Interface to Multimethod::Module mixin multimethod



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# File 'lib/multimethod/table.rb', line 25

def install_method(mod, body, file = nil, line = nil)
  file ||= __FILE__
  line ||= __LINE__
  verbose = nil
  #if body =~ /def bar\(x, y\)/
  #  verbose = 1
  #end

  # Parse the signature from the method body
  signature = Signature.new
  signature.mod = mod
  signature.verbose = verbose
  signature.file = file
  signature.line = line
  new_body = signature.scan_string(body.clone)
  
  # Get our Multimethod for this
  mm = lookup_multimethod(signature.name)
  mm.install_dispatch(mod)
  m = mm.new_method_from_signature(signature)

  # Replace the multimethod signature with a plain Ruby signature.
  new_body = m.to_ruby_def + new_body

  #if true || m.signature.restarg
  #   $stderr.puts "install_method(#{mod}) => #{m.to_ruby_signature}:\n#{new_body}"
  #end

  # Evaluate the new method body.     
  mod.module_eval(new_body, file, line)
end

#lookup_multimethod(name) ⇒ Object 



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# File 'lib/multimethod/table.rb', line 97

def lookup_multimethod(name)
  name = name.to_s

  # THREAD CRITICAL BEGIN
  unless mm = @multimethod_by_name[name]
    mm = Multimethod.new(name)
    mm.table = self
    @multimethod_by_name[name] = mm
    @multimethod << mm
  end
  # THREAD CRITICAL END

  mm
end

#name_to_object(name, scope = nil, file = nil, line = nil) ⇒ Object

Support



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# File 'lib/multimethod/table.rb', line 126

def name_to_object(name, scope = nil, file = nil, line = nil)
  scope ||= Kernel
  # THREAD CRITICAL BEGIN
  unless x = (@name_to_object[scope] ||= { })[name]
    # $stderr.puts " name_to_object(#{name.inspect}) in #{scope}"
    x = 
      @name_to_object[scope][name] = 
      scope.module_eval(name, file || __FILE__, line || __LINE__)
  end
  # THREAD CRITICAL END

  x
end

#remove_method(signature) ⇒ Object 



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# File 'lib/multimethod/table.rb', line 89

def remove_method(signature)
  x = find_method(signature)
  raise("Found #{x.size} multimethods: #{x.inspect}") if x.size > 1
  x = x[0]
  x.multimethod.remove_method(x)
end