/// <summary>
/// Bind 'this'
/// </summary>
/// <param name="instance">The instance</param>
/// <returns></returns>
public LoxFunction Bind(LoxInstance instance)
{
LoxEnvironment environment = new LoxEnvironment(_closure);
environment.Define("this", instance);
return(new LoxFunction(_declaration, environment, _is_initializer));
}
public object Call(Interpreter interpreter, IList <object> arguments)
{
// Environment
LoxEnvironment environment = new LoxEnvironment(_closure);
// Arguments
for (int i = 0; i < _declaration.Parameters.Count(); i++)
{
environment.Define(_declaration.Parameters[i].Lexeme, arguments[i]);
}
// Execute
try
{
interpreter.ExecuteBlock(_declaration.Body, environment);
}
catch (ReturnException return_value)
{
// We hit a return statement
return(return_value.Value);
}
if (_is_initializer)
{
return(_closure.GetAt(0, "this"));
}
return(null);
}
public Interpreter(IErrorHandler error_handler)
{
_error_handler = error_handler;
// We need to set this here in C#
_environment = _globals;
// Add some native functions
_globals.Define("clock", new NativeFunctions.Clock());
}
private LoxEnvironment Ancestor(int distance)
{
LoxEnvironment environment = this;
for (int i = 0; i < distance; i++)
{
environment = environment.Enclosing;
}
return(environment);
}
/// <summary>
/// Ececute a block of statements
/// </summary>
/// <param name="statements">The statements</param>
/// <param name="environment">The environment</param>
public void ExecuteBlock(IEnumerable <Stmt> statements, LoxEnvironment environment)
{
// Save the current environment
LoxEnvironment previous = this._environment;
try
{
// Set the new environment
this._environment = environment;
foreach (Stmt statement in statements)
{
Execute(statement);
}
}
finally
{
// Restore the old environment
this._environment = previous;
}
}
public object Visit(Stmt.Class stmt)
{
_environment.Define(stmt.Name.Lexeme, null);
// Superclass
object superclass = null;
if (stmt.Superclass != null)
{
superclass = Evaluate(stmt.Superclass);
if (!(superclass is LoxClass))
{
throw new RuntimeErrorException(stmt.Superclass.Name, "Superclass must be a class.");
}
_environment = new LoxEnvironment(_environment);
_environment.Define("super", superclass);
}
// Methods
HashMap <string, LoxFunction> methods = new HashMap <string, LoxFunction>();
foreach (Stmt.Function method in stmt.Methods)
{
LoxFunction function = new LoxFunction(method, _environment, method.Name.Lexeme.Equals("init"));
methods.Put(method.Name.Lexeme, function);
}
LoxClass @class = new LoxClass(stmt.Name.Lexeme, (LoxClass)superclass, methods);
if (superclass != null)
{
_environment = _environment.Enclosing;
}
_environment.Assign(stmt.Name, @class);
return(null);
}
public LoxEnvironment(LoxEnvironment enclosing)
{
this.Enclosing = enclosing;
}
public LoxEnvironment()
{
this.Enclosing = null;
}
public LoxFunction(Stmt.Function declaration, LoxEnvironment closure, bool is_initializer)
{
_declaration = declaration;
_closure = closure;
_is_initializer = is_initializer;
}
