Class: Loxxy::BackEnd::LoxFunction

Inherits:
Object
  • Object
show all
Defined in:
lib/loxxy/back_end/lox_function.rb

Overview

rubocop: disable Style/AccessorGrouping Representation of a Lox function. It is a named slot that can be associated with a value at the time.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(aName, parameterList, aBody, anEngine) ⇒ LoxFunction

Create a function with given name

Parameters:

  • aName (String) —

    The name of the variable



22
23
24
25
26
27
28
29
 
# File 'lib/loxxy/back_end/lox_function.rb', line 22

def initialize(aName, parameterList, aBody, anEngine)
  @name = aName.dup
  @parameters = parameterList
  @body = aBody.kind_of?(Ast::LoxNoopExpr) ? aBody : aBody.subnodes[0]
  @stack = anEngine.stack
  @closure = anEngine.symbol_table.current_env
  anEngine.symbol_table.current_env.embedding = true
end

Instance Attribute Details

#body ⇒ Object (readonly)

Returns the value of attribute body.



16
17
18
 
# File 'lib/loxxy/back_end/lox_function.rb', line 16

def body
  @body
end

#closure ⇒ Object (readonly)

Returns the value of attribute closure.



18
19
20
 
# File 'lib/loxxy/back_end/lox_function.rb', line 18

def closure
  @closure
end

#name ⇒ String (readonly)

Returns The name of the function (if any).

Returns:

  • (String) —

    The name of the function (if any)



12
13
14
 
# File 'lib/loxxy/back_end/lox_function.rb', line 12

def name
  @name
end

#parameters ⇒ Array<> (readonly)

Returns the parameters.

Returns:

  • (Array<>) —

    the parameters



15
16
17
 
# File 'lib/loxxy/back_end/lox_function.rb', line 15

def parameters
  @parameters
end

#stack ⇒ Object (readonly)

Returns the value of attribute stack.



17
18
19
 
# File 'lib/loxxy/back_end/lox_function.rb', line 17

def stack
  @stack
end

Instance Method Details

#! ⇒ Datatype::False

Logical negation. As a function is a truthy thing, its negation is thus false.

Returns:



60
61
62
 
# File 'lib/loxxy/back_end/lox_function.rb', line 60

def !
  Datatype::False.instance
end

#accept(_visitor) ⇒ Object 



35
36
37
 
# File 'lib/loxxy/back_end/lox_function.rb', line 35

def accept(_visitor)
  stack.push self
end

#arity ⇒ Object 



31
32
33
 
# File 'lib/loxxy/back_end/lox_function.rb', line 31

def arity
  parameters ? parameters.size : 0
end

#call(engine, aVisitor) ⇒ Object 



39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
 
# File 'lib/loxxy/back_end/lox_function.rb', line 39

def call(engine, aVisitor)
  # new_env = Environment.new(engine.symbol_table.current_env)
  new_env = Environment.new(closure)
  engine.symbol_table.enter_environment(new_env)

  parameters&.each do |param_name|
    local = Variable.new(param_name, stack.pop)
    engine.symbol_table.insert(local)
  end

  catch(:return) do
    (body.nil? || body.kind_of?(Ast::LoxNoopExpr)) ? Datatype::Nil.instance : body.accept(aVisitor)
    throw(:return)
  end

  engine.symbol_table.leave_environment
end

#to_str ⇒ Object

Text representation of a Lox function



65
66
67
 
# File 'lib/loxxy/back_end/lox_function.rb', line 65

def to_str
  "<fn #{name}>"
end