public object visitClassStatement(Statement.Class classStatement)
{
ClassType enclosingClass = currentClass;
currentClass = ClassType.CLASS;
declare(classStatement.name);
define(classStatement.name);
Dictionary <string, bool> superclassDuplicates = new Dictionary <string, bool>();
if (classStatement.superclass.Count != 0)
{
currentClass = ClassType.SUBCLASS;
foreach (Expr.Variable superClass in classStatement.superclass)
{
superclassDuplicates.TryGetValue(superClass.name.lexeme, out bool value);
if (value)
{
Lox.error(superClass.name, "A class can't inherit from the same class twice.");
}
else
{
superclassDuplicates[superClass.name.lexeme] = true;
}
if (classStatement.name.lexeme.Equals(superClass.name.lexeme))
{
Lox.error(superClass.name, "A class can't inherit from itself.");
}
resolve(superClass);
}
beginScope();
Variable sup = new Variable(classStatement.name); //Class name is a variable, but the user likely won't want to be warned about it being unused.
sup.initialized = true;
sup.used = true;
scopes.Peek().Add("super", sup);
}
beginScope();
Token thisVar = new Token(TokenType.THIS_OBJECT, "this", null, -1, -1);
Variable varHacky = new Variable(thisVar);
varHacky.initialized = true;
scopes.Peek().Add("this", varHacky);
foreach (Statement.function method in classStatement.methods)
{
FunctionType declaration = FunctionType.METHOD;
if (method.name.lexeme.Equals("init"))
{
declaration = FunctionType.INITIALIZER;
}
if (method._params.Count == 1 && method._params.ElementAt(0).type == TokenType.SEMICOLON && method._params.ElementAt(0).lexeme.Equals("getter"))
{
FunctionType previous = currentFunction;
currentFunction = FunctionType.METHOD;
Variable getter = new Variable(method.name);
getter.initialized = (method.body.Count != 0);
getter.used = true; //We don't want warnings for member functions/getters.
resolve(method.body);
scopes.Peek().Add(method.name.lexeme, getter);
currentFunction = previous;
}
else
{
resolveFunction(method, declaration);
}
}
endScope();
if (classStatement.superclass.Count > 0)
{
endScope();
}
currentClass = enclosingClass;
return(null);
}
public object visitClassStatement(Statement.Class classStatement)
{
List <LoxClass> superClasses = new List <LoxClass>();
if (classStatement.superclass.Count != 0)
{
foreach (Object superClass in classStatement.superclass)
{
Object eval = evaluate((Expr.Variable)superClass);
if (!(eval is LoxClass))
{
throw new Exceptions.RuntimeError(new HelperFunctions.GetToken().evaluate((Expr)superClass), "Superclass must be a class.");
}
else
{
superClasses.Add((LoxClass)eval);
}
}
}
environment.define(classStatement.name.lexeme, null, classStatement.name);
if (classStatement.superclass.Count != 0)
{
environment = new Environment(environment);
environment.define("super", superClasses);
}
Dictionary <string, LoxFunction> methods = new Dictionary <string, LoxFunction>();
Dictionary <LoxFunction, Token> getters = new Dictionary <LoxFunction, Token>();
List <Statement.function> methodsList = classStatement.methods;
foreach (Statement.function method in methodsList)
{
if (method._params.Count == 1 && method._params.ElementAt(0).type == TokenType.SEMICOLON && method._params.ElementAt(0).lexeme.Equals("getter"))
{
Statement.function noParams = new Statement.function(method.name, new List <Token>(), method.body);
LoxFunction getter = new LoxFunction(noParams, environment, false, true);
methods.Add(method.name.lexeme, getter);
getters[getter] = method.name;
}
else
{
LoxFunction function = new LoxFunction(method, environment, method.name.lexeme.Equals("init"));
if (!methods.ContainsKey(method.name.lexeme))
{
methods.Add(method.name.lexeme, function);
}
else
{
throw new Exceptions.RuntimeError(method.name, "Cannot have two functions with the same name in the same class.");
}
}
}
LoxClass _class = new LoxClass(classStatement.name.lexeme, superClasses, methods);
foreach (Statement.function staticFunction in classStatement.staticFunctions)
{
_class.set(staticFunction.name, staticFunction);
}
foreach (LoxFunction getter in getters.Keys)
{
_class.set(getters[getter], getter);
}
if (superClasses.Count != 0)
{
environment = environment.enclosing;
}
environment.assign(classStatement.name, _class);
return(null);
}