How exception handling works.

complex.cs

private static void f()
{
	ThreadExEnv env = Thread.current().getExEnv();
	void() fin = void () ->
	{
		// finally block
		// ...
	};
	if (!env.registerHandler(fin))
	{
		// try block
		// ...
		env.leave();
	}
	else
	{
		Exception e = env.getEx();
		Type t = e.getType();
		if (t.subTypeOf(typeof(NullPtrException)))
		{
			NullPtrException npe = Object.forceCast<NullPtrException>(e);
			// catch (NullPtrException npe) block
			// ...
			env.leave();
		}
		else if (t.subTypeOf(typeof(IOException)))
		{
			IOException ioe = Object.forceCast<IOException>(e);
			// catch (IOException ioe) block
			// ...
			env.leave();
		}
		else
		{
			env.fallThrough();
		}
	}
}

private static void g(Exception e)
{
	Thread.current().getExEnv().raise(e);
}

simple.cs

private static void f()
{
	try
	{
		// try block
		// ...
	}
	catch (NullPtrException npe)
	{
		// catch (NullPtrException npe) block
		// ...
	}
	catch (IOException ioe)
	{
		// catch (IOException ioe) block
		// ...
	}
	finally
	{
		// finally block
		// ...
	}
}

private static void g(Exception e)
{
	throw e;
}