public Node ProcedureDeclaration()
{
Expect(TokenCategory.PROCEDURE);
var procedure_node = new ProcedureDeclarationNode()
{
AnchorToken = Expect(TokenCategory.IDENTIFIER)
};
Expect(TokenCategory.PARENTHESIS_OPEN);
procedure_node.Add(new ParameterDeclarationNode()
{
ZeroOrMore(TokenCategory.IDENTIFIER, ParameterDeclaration)
});
Expect(TokenCategory.PARENTHESIS_CLOSE);
var typeNode = Optional(TokenCategory.COLON, Type, true);
if (typeNode == null)
{
typeNode = new VoidTypeNode();
}
procedure_node.Add(typeNode);
Expect(TokenCategory.SEMICOLON);
procedure_node.Add(Optional(TokenCategory.CONST, () =>
{
var node = new ConstantListNode()
{
AnchorToken = Expect(TokenCategory.CONST)
};
node.Add(OneOrMore(TokenCategory.IDENTIFIER, ConstantDeclaration));
return(node);
}));
procedure_node.Add(Optional(TokenCategory.VAR, () =>
{
var node = new VariableDeclarationNode()
{
AnchorToken = Expect(TokenCategory.VAR)
};
node.Add(OneOrMore(TokenCategory.IDENTIFIER, VariableDeclaration));
return(node);
}));
Expect(TokenCategory.BEGIN);
procedure_node.Add(new StatementListNode()
{
ZeroOrMore(firstOfStatement, Statement)
});
Expect(TokenCategory.END);
Expect(TokenCategory.SEMICOLON);
return(procedure_node);
}
private TypeNode ReturnType()
{
TypeNode itsAST = null; // in case there is a syntactic error
SourceCodePosition itsPos = _currentToken.SourcePosition;
if (Array.Exists(_typeFirstSet, e => e == _currentToken.Type))
{
itsAST = Type();
}
else if (_currentToken.Type == Token.TokenType.Void)
{
itsAST = new VoidTypeNode(itsPos);
Accept(Token.TokenType.Void);
}
else
{
Error("Expected int, real, string, boolean, identifier, void or array type");
}
return(itsAST);
}
public object Visit(VoidTypeNode n, object o)
{
return(null);
}
public void Visit(VoidTypeNode node)
{
builder.Append("void");
}
public Type Visit(VoidTypeNode node)
{
return(Type.VOID);
}
public object Visit(VoidTypeNode n, object o)
{
Append("void");
return(null);
}
