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(*
* The transpose of a graph
*
* -- Allen
*)
signature REVERSED_GRAPH_VIEW =
sig
val rev_view : ('n,'e,'g) Graph.graph -> ('n,'e,'g) Graph.graph
end
structure ReversedGraphView : REVERSED_GRAPH_VIEW =
struct
structure G = Graph
fun rev_view (G.GRAPH G) =
let fun swap f (i,j,e) = f (j,i,e)
fun swap' f (i,j) = f (j,i)
fun swap'' (i,j,e) = (j,i,e)
fun flip es = map (fn (i,j,e) => (j,i,e)) es
in
G.GRAPH
{ name = #name G,
graph_info = #graph_info G,
new_id = #new_id G,
add_node = #add_node G,
add_edge = swap (#add_edge G),
remove_node = #remove_node G,
set_in_edges = fn (j,es) => #set_out_edges G (j,flip es),
set_out_edges = fn (i,es) => #set_in_edges G (i,flip es),
set_entries = #set_exits G,
set_exits = #set_entries G,
garbage_collect = #garbage_collect G,
nodes = #nodes G,
edges = fn () => map swap'' (#edges G ()),
order = #order G,
size = #size G,
capacity = #capacity G,
out_edges = fn i => map swap'' (#in_edges G i),
in_edges = fn i => map swap'' (#out_edges G i),
succ = #pred G,
pred = #succ G,
has_edge = swap' (#has_edge G),
has_node = #has_node G,
node_info = #node_info G,
entries = #exits G,
exits = #entries G,
entry_edges = #exit_edges G,
exit_edges = #entry_edges G,
forall_nodes = #forall_nodes G,
forall_edges = fn f => #forall_edges G (swap f)
(*
fold_nodes = #fold_nodes G,
fold_edges = fn f => fn u =>
#fold_edges G (fn ((i,j,e),l) => f((j,i,e),l)) u *)
}
end
end
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