Class: Pione::Lang::ParamDeclaration

Inherits:
Declaration
  • Object
show all
Defined in:
lib/pione/lang/declaration.rb

Overview

ParamDeclaration is a declaration thae the parameter is neeeded.

Instance Method Summary collapse

Methods inherited from Declaration

#eval!, inherited

Methods included from Util::Positionable

#line_and_column, #pos, #set_source_position

Instance Method Details

#eval(env) ⇒ Object

Add the parameter in current rule definition.



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# File 'lib/pione/lang/declaration.rb', line 131

def eval(env)
  # get variable
  var = get_reference(env, expr1, Variable)

  # we don't permit to declare parameters of other packages
  if not(var.package_id.nil?) and var.package_id != env.current_package_id
    raise ParamDeclarationError.new(self)
  end

  # get the value(don't evaluate in this time)
  default_val = expr2

  begin
    env.variable_get(var)
  rescue UnboundError
    # bind default value
    env.variable_set(var, default_val)
  end

  param = ParameterDefinition.new(type, var.name, default_val)

  # select target definition
  definition = nil
  if env.current_definition
    # in rule definition context
    definition = env.current_definition
  else
    # in package context
    definition = env.package_get(PackageExpr.new(package_id: var.package_id))
  end

  if definition.param_definition[var.name]
    raise RebindError.new(var)
  else
    definition.param_definition[var.name] = param
  end
end

#set_type(new_type) ⇒ Object 



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# File 'lib/pione/lang/declaration.rb', line 126

def set_type(new_type)
  set(type: new_type)
end