Function compile 

pub fn compile<'a, G>(
    get_node: GetNode<'a>,
    graph: G,
    vm: &mut Engine,
    entrypoints: &[Entrypoint],
    config: &Config,
) -> Result<Compiled, CompileError>
where
    G: Data<EdgeWeight = Edge> + IntoEdgesDirected + IntoNodeReferences + NodeIndexable + Visitable + Copy,
    G::NodeWeight: Node,

Compile the graph into a Steel module and run it in the VM.

The module runs as a single program so that the engine registers Compiled::src verbatim as one source: subsequent steel errors then carry spans whose offsets index into it directly (see steel_err_node).