Apply GRAFTS to the OUTPUTS of DRV and all their dependencies, recursively. That is, if GRAFTS apply only indirectly to DRV, graft the dependencies of DRV, and graft DRV itself to refer to those grafted dependencies.

Return a derivation called NAME, which applies GRAFTS to the specified OUTPUTS of DRV. This procedure performs "shallow" grafting in that GRAFTS are not recursively applied to dependencies of DRV.

Return the number of nodes reachable from NODES along NODE-EDGES.

Do a depth-first traversal of NODES along NODE-EDGES, calling PROC with each node and the current result, and visiting each reachable node exactly once. NODES must be a list of nodes, and NODE-EDGES must be a one-argument procedure as returned by 'node-edges' or 'node-back-edges'.

Return as a monadic value the shortest path, represented as a list, from NODE1 to NODE2 of the given TYPE. Return #f when there is no path.

Return the graph backend called NAME. Raise an error if it is not found.

Write to PORT the representation of the DAG with the given SINKS, using the given BACKEND. Use NODE-TYPE to traverse the DAG. When REVERSE-EDGES? is true, draw reverse arrows. Do not represent nodes whose distance to one of the SINKS is greater than MAX-DEPTH.