<p>
A complete program is created by linking a single, unimported package
called the <i>main package</i> with all the packages it imports, transitively.
The main package must
have package name <code>main</code> and
declare a function <code>main</code> that takes no
arguments and returns no value.
</p>

<pre>
func main() { … }
</pre>

<p>

		// the jump table at all.
		// We check that min <= idx <= max and jump around the jump table
		// if that test fails.
		// We implement min <= idx <= max with 0 <= idx-min <= max-min, because
		// we'll need idx-min anyway as the control value for the jump table.
		var min, max uint64
		if unsigned {
			min, _ = constant.Uint64Val(n.Cases[0])
			max, _ = constant.Uint64Val(n.Cases[len(n.Cases)-1])