//sub-body ::= '{' <local-var-decl>* <statement>* '}'
private void ParseSubBody()
{
Match(new Token(TokenType.Symbol, "{"));
ParseLocalVarDecls();
//Notify the code generator -- now _currentSub has full information
//about the subroutine's parameters and local variables.
switch (_currentSub.Kind)
{
case SubroutineKind.Constructor:
_codeGenerator.ConstructorDeclaration(_currentSub);
break;
case SubroutineKind.Function:
_codeGenerator.FunctionDeclaration(_currentSub);
break;
case SubroutineKind.Method:
_codeGenerator.MethodDeclaration(_currentSub);
break;
default:
ThrowCompilationException("Invalid value for _currentSub.Kind: " + _currentSub.Kind);
break;
}
ParseStatements();
//Make sure the method ends with 'return'. If the method is void,
//return an an arbitrary value. This could be left to the CG's
//discretion as well.
if (!_wasLastStatementReturn)
{
if (_currentSub.ReturnType == "void")
{
_codeGenerator.IntConst(0);
_codeGenerator.Return();
//NOTE: This is a deviation from the original Jack syntax,
//in which all methods must end with a 'return' statement,
//even void methods.
}
else
{
ThrowCompilationException("Non-void method must return a value");
}
}
_wasLastStatementReturn = false;
_codeGenerator.EndSubroutine();
//This is the last thing we do because it may advance us to the
//next line, but we want accurate compilation errors.
Match(new Token(TokenType.Symbol, "}"));
}