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/* valatypecheck.vala
*
* Copyright (C) 2006-2010 Jürg Billeter
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Author:
* Jürg Billeter <j@bitron.ch>
*/
using GLib;
/**
* Represents a type check (`is`) expression in the source code.
*/
public class Vala.TypeCheck : Expression {
/**
* The expression to be checked.
*/
public Expression expression {
get { return _expression; }
set {
_expression = value;
_expression.parent_node = this;
}
}
/**
* The type to be matched against.
*/
public DataType type_reference {
get { return _data_type; }
set {
_data_type = value;
_data_type.parent_node = this;
}
}
Expression _expression;
private DataType _data_type;
/**
* Creates a new type check expression.
*
* @param expr an expression
* @param type a data type
* @param source reference to source code
* @return newly created type check expression
*/
public TypeCheck (Expression expr, DataType type, SourceReference source) {
expression = expr;
type_reference = type;
source_reference = source;
}
public override void accept (CodeVisitor visitor) {
visitor.visit_type_check (this);
visitor.visit_expression (this);
}
public override void accept_children (CodeVisitor visitor) {
expression.accept (visitor);
type_reference.accept (visitor);
}
public override bool is_pure () {
return expression.is_pure ();
}
public override void replace_type (DataType old_type, DataType new_type) {
if (type_reference == old_type) {
type_reference = new_type;
}
}
public override void replace_expression (Expression old_node, Expression new_node) {
if (expression == old_node) {
expression = new_node;
}
}
public override bool check (CodeContext context) {
if (checked) {
return !error;
}
checked = true;
expression.check (context);
type_reference.check (context);
if (expression.value_type == null) {
Report.error (expression.source_reference, "invalid left operand");
error = true;
return false;
}
if (type_reference.data_type == null) {
/* if type resolving didn't succeed, skip this check */
error = true;
return false;
}
if (context.profile == Profile.GOBJECT && type_reference.has_type_arguments ()) {
Report.warning (_data_type.source_reference, "Type argument list has no effect");
}
value_type = context.analyzer.bool_type;
return !error;
}
public override void emit (CodeGenerator codegen) {
expression.emit (codegen);
codegen.visit_type_check (this);
codegen.visit_expression (this);
}
public override string to_string () {
return "(%s is %s)".printf (expression.to_string (), type_reference.to_string ());
}
}
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