public static UnifiedExpression CreateIterationStatement(XElement node)
{
Contract.Requires(node != null);
Contract.Requires(node.Name() == "iteration_statement");
/*
* iteration_statement
* : 'while' '(' expression ')' statement
| 'do' statement 'while' '(' expression ')' ';'
| 'for' '(' expression_statement expression_statement expression? ')' statement
*/
var first = node.FirstElement().Value;
var body =
UnifiedBlock.Create(
CreateStatement(node.FirstElement("statement")));
switch (first)
{
case "while":
return
(UnifiedWhile.Create(
CreateExpression(node.NthElement(2)).First(),
body));
case "do":
return
(UnifiedDoWhile.Create(
CreateExpression(node.NthElement(4)).First(),
body));
case "for":
var step = node.Element("expression") != null?
CreateExpression
(
node
.
FirstElement
(
"expression"))
.
First
()
: null;
return(UnifiedFor.Create(
CreateExpressionStatement(node.NthElement(2)),
CreateExpressionStatement(node.NthElement(3)),
step, body));
default:
throw new InvalidOperationException();
}
}
public UnifiedElement VisitForStatement(
ForStatement forStmt, object data)
{
// C#はstatementは一つのStatementあるいはBlockなためFirstOrDefaultで問題ない。
// 複数あるのはVBを表す場合のため。
var initStmt = forStmt.Initializers
.Select(s => s.TryAcceptForExpression(this))
.FirstOrDefault();
var condExpr = forStmt.Condition.TryAcceptForExpression(this);
var stepStmt = forStmt.Iterators
.Select(s => s.TryAcceptForExpression(this))
.FirstOrDefault();
var body =
forStmt.EmbeddedStatement.TryAcceptForExpression(this).
ToBlock();
return(UnifiedFor.Create(initStmt, condExpr, stepStmt, body));
}