Class: FunctioncallNode

Inherits:
Object
  • Object
show all
Includes:
STL
Defined in:
lib/nodes.rb

Overview

Class for calling functions.

Instance Method Summary collapse

Methods included from STL

delete_element, get_element, pop, print, push, size

Constructor Details

#initialize(identifier, object = nil, arguments = []) ⇒ FunctioncallNode

Returns a new instance of FunctioncallNode.



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# File 'lib/nodes.rb', line 127

def initialize(identifier, object = nil, arguments = [])
  @identifier = identifier.value
  @arguments = arguments
  @object = object
end

Instance Method Details

#evaluate(scope) ⇒ Object 



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# File 'lib/nodes.rb', line 162

def evaluate(scope)

  # Check if scope of identifier. If it exist but is not defined as a function: raise TypeError
  id_scope = scope.get_scope(@identifier)
  if id_scope && !id_scope.is_function?(@identifier)
    raise TypeError, "Identifier #{@identifier} is not defined as a function."
  end

  
  # Check if the function has been called as a method on a object (Ex. a.print();). Add object as a argument if true.

  if @object && !@arguments.include?(@object)
    @arguments.unshift(@object)
  end

  # Check if no identifier has been found in scope.
  if !id_scope

    # Check if function part of STL. if true: call function, else raise NameError.
    if STL.respond_to?(@identifier)
      method = STL.method(@identifier)
      parameters = method.parameters
      validate_arguments(parameters)
      evaluate_STL_function(scope)
    else
      raise NameError, "Function #{@identifier} not defined."
    end

    # If identifier is user defined function, call it.
  else
    function = id_scope.get_identifier(@identifier)
    parameters = function[:parameters]
    block = function[:block]
    validate_arguments(parameters)
    evaluate_block(parameters, block,scope,id_scope)
  end
end

#evaluate_block(parameters, block, current_scope, declared_scope) ⇒ Object

Evaluate code-block of user defined function.



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# File 'lib/nodes.rb', line 148

def evaluate_block(parameters, block, current_scope, declared_scope)
  
  # Create new scope for function with the scope where the function was declared as its parent scope. 
  new_scope = Scope.new(declared_scope)

  # Set local variables for function with values from arguments
  parameters.zip(@arguments).each do |parameter, argument|
    new_scope.set_variable(parameter, '=', argument.evaluate(current_scope))
  end

  result = block.evaluate(new_scope)
  return result.value if result.is_a?(ReturnValue)
end

#evaluate_STL_function(scope) ⇒ Object

Calls builtin-function.



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# File 'lib/nodes.rb', line 141

def evaluate_STL_function(scope)
  args = @arguments.map {|arg| arg.evaluate(scope)}
  result = STL.send(@identifier, *args)
  return result
end

#validate_arguments(parameters) ⇒ Object

Checks if the arguments given is the same number of expected parameters.



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# File 'lib/nodes.rb', line 134

def validate_arguments(parameters)
  if @arguments.size != parameters.size
    raise ArgumentError, "Wrong number of arguments (given: #{@arguments.size} expected: #{parameters.size})."
  end
end