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/* valadostatement.vala
*
* Copyright (C) 2006-2009 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 do iteration statement in the source code.
*/
public class Vala.DoStatement : CodeNode, Statement {
/**
* Specifies the loop body.
*/
public Block body {
get {
return _body;
}
set {
_body = value;
_body.parent_node = this;
}
}
/**
* Specifies the loop condition.
*/
public Expression condition {
get {
return _condition;
}
set {
_condition = value;
_condition.parent_node = this;
}
}
private Expression _condition;
private Block _body;
/**
* Creates a new do statement.
*
* @param body loop body
* @param condition loop condition
* @param source_reference reference to source code
* @return newly created do statement
*/
public DoStatement (Block body, Expression condition, SourceReference? source_reference = null) {
this.condition = condition;
this.source_reference = source_reference;
this.body = body;
}
public override void accept (CodeVisitor visitor) {
visitor.visit_do_statement (this);
}
public override void accept_children (CodeVisitor visitor) {
body.accept (visitor);
condition.accept (visitor);
visitor.visit_end_full_expression (condition);
}
bool always_true (Expression condition) {
var literal = condition as BooleanLiteral;
return (literal != null && literal.value);
}
public override bool check (CodeContext context) {
// convert to simple loop
// do not generate variable and if block if condition is always true
if (always_true (condition)) {
var loop = new Loop (body, source_reference);
var parent_block = (Block) parent_node;
parent_block.replace_statement (this, loop);
return loop.check (context);
}
var block = new Block (source_reference);
var first_local = new LocalVariable (context.analyzer.bool_type.copy (), get_temp_name (), new BooleanLiteral (true, source_reference), source_reference);
block.add_statement (new DeclarationStatement (first_local, source_reference));
var if_condition = new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, condition, condition.source_reference);
var true_block = new Block (condition.source_reference);
true_block.add_statement (new BreakStatement (condition.source_reference));
var if_stmt = new IfStatement (if_condition, true_block, null, condition.source_reference);
var condition_block = new Block (condition.source_reference);
condition_block.add_statement (if_stmt);
var first_if = new IfStatement (new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, new MemberAccess.simple (first_local.name, source_reference), source_reference), condition_block, null, source_reference);
body.insert_statement (0, first_if);
body.insert_statement (1, new ExpressionStatement (new Assignment (new MemberAccess.simple (first_local.name, source_reference), new BooleanLiteral (false, source_reference), AssignmentOperator.SIMPLE, source_reference), source_reference));
block.add_statement (new Loop (body, source_reference));
var parent_block = (Block) parent_node;
parent_block.replace_statement (this, block);
return block.check (context);
}
}
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