/// <summary>
/// Creates a Linq expression for a <see cref="CommandAst" /> representing
/// the "lock" command.
/// </summary>
/// <param name="commandAst">The AST to convert.</param>
/// <param name="targetAst">The AST containing the target of the keyword.</param>
/// <param name="bodyAst">The AST containing the body of the keyword.</param>
/// <param name="visitor">The <see cref="CompileVisitor" /> requesting the expression.</param>
/// <returns>An expression representing the command.</returns>
protected override Expression ProcessObjectAndBody(
CommandAst commandAst,
CommandElementAst targetAst,
ScriptBlockExpressionAst bodyAst,
CompileVisitor visitor)
{
var lockVar = Expression.Variable(typeof(object));
var lockTakenVar = Expression.Variable(typeof(bool));
return(visitor.NewBlock(() =>
Expression.Block(
typeof(void),
new[] { lockVar, lockTakenVar },
Expression.Call(
ReflectionCache.Monitor_Enter,
Expression.Assign(
lockVar,
Expression.Convert(
targetAst.Compile(visitor),
typeof(object))),
lockTakenVar),
Expression.TryFinally(
bodyAst.ScriptBlock.EndBlock.Compile(visitor),
Expression.IfThen(
lockTakenVar,
Expression.Call(
ReflectionCache.Monitor_Exit,
lockVar))))));
}
/// <summary>
/// Creates a Linq expression for a <see cref="CommandAst" /> representing
/// the "with" command.
/// </summary>
/// <param name="commandAst">The AST to convert.</param>
/// <param name="targetAst">The AST containing the target of the keyword.</param>
/// <param name="bodyAst">The AST containing the body of the keyword.</param>
/// <param name="visitor">The <see cref="CompileVisitor" /> requesting the expression.</param>
/// <returns>An expression representing the command.</returns>
protected override Expression ProcessObjectAndBody(
CommandAst commandAst,
CommandElementAst targetAst,
ScriptBlockExpressionAst bodyAst,
CompileVisitor visitor)
{
var disposeVar = Expression.Variable(typeof(IDisposable));
return(visitor.NewBlock(() =>
Expression.Block(
typeof(void),
new[] { disposeVar },
Expression.Assign(
disposeVar,
Expression.Convert(
targetAst.Compile(visitor),
typeof(IDisposable))),
Expression.TryFinally(
bodyAst.ScriptBlock.EndBlock.Compile(visitor),
Expression.Call(disposeVar, ReflectionCache.IDisposable_Dispose)))));
}