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/* valaifstatement.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 an if selection statement in the source code.
*/
public class Vala.IfStatement : CodeNode, Statement {
/**
* The boolean condition to evaluate.
*/
public Expression condition {
get {
return _condition;
}
private set {
_condition = value;
_condition.parent_node = this;
}
}
/**
* The statement to be evaluated if the condition holds.
*/
public Block true_statement {
get { return _true_statement; }
private set {
_true_statement = value;
_true_statement.parent_node = this;
}
}
/**
* The optional statement to be evaluated if the condition doesn't hold.
*/
public Block? false_statement {
get { return _false_statement; }
private set {
_false_statement = value;
if (_false_statement != null)
_false_statement.parent_node = this;
}
}
private Expression _condition;
private Block _true_statement;
private Block _false_statement;
/**
* Creates a new if statement.
*
* @param cond a boolean condition
* @param true_stmt statement to be evaluated if condition is true
* @param false_stmt statement to be evaluated if condition is false
* @return newly created if statement
*/
public IfStatement (Expression cond, Block true_stmt, Block? false_stmt, SourceReference? source = null) {
condition = cond;
true_statement = true_stmt;
false_statement = false_stmt;
source_reference = source;
}
public override void accept (CodeVisitor visitor) {
visitor.visit_if_statement (this);
}
public override void accept_children (CodeVisitor visitor) {
condition.accept (visitor);
visitor.visit_end_full_expression (condition);
true_statement.accept (visitor);
if (false_statement != null) {
false_statement.accept (visitor);
}
}
public override void replace_expression (Expression old_node, Expression new_node) {
if (condition == old_node) {
condition = new_node;
}
}
public override void get_error_types (Collection<DataType> collection, SourceReference? source_reference = null) {
condition.get_error_types (collection, source_reference);
true_statement.get_error_types (collection, source_reference);
if (false_statement != null) {
false_statement.get_error_types (collection, source_reference);
}
}
public override bool check (CodeContext context) {
if (checked) {
return !error;
}
checked = true;
condition.target_type = context.analyzer.bool_type.copy ();
condition.check (context);
true_statement.check (context);
if (false_statement != null) {
false_statement.check (context);
}
if (condition.error) {
/* if there was an error in the condition, skip this check */
error = true;
return false;
}
if (condition.value_type == null || !condition.value_type.compatible (context.analyzer.bool_type)) {
error = true;
Report.error (condition.source_reference, "Condition must be boolean");
return false;
}
return !error;
}
public override void emit (CodeGenerator codegen) {
condition.emit (codegen);
codegen.visit_end_full_expression (condition);
codegen.visit_if_statement (this);
}
}
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