下記のプログラムは編集して実行できます。

-- -- -- Graph demonstration -- -- -- -- Matcher definition -- def graph {a, b} (a: Matcher b) : Matcher [Edge b] := set (edge a) def edge {a, b} (a: Matcher b) : Matcher (Edge b) := algebraicDataMatcher | edge a a -- -- Sample data -- def graphData1 : [Edge Integer] := [Edge 1 4, Edge 2 1, Edge 3 1, Edge 3 2, Edge 4 3, Edge 5 1, Edge 5 4] def graphData2 : [Edge Integer] := [Edge 1 4, Edge 1 5, Edge 1 8, Edge 1 10, Edge 2 3, Edge 2 6, Edge 2 12, Edge 3 2, Edge 3 7, Edge 3 9, Edge 4 1, Edge 4 6, Edge 5 1, Edge 5 8, Edge 5 9, Edge 5 11, Edge 6 2, Edge 6 4, Edge 6 10, Edge 6 12, Edge 7 3, Edge 7 9, Edge 7 11, Edge 8 1, Edge 8 5, Edge 9 3, Edge 9 5, Edge 9 7, Edge 10 1, Edge 10 6, Edge 10 12, Edge 11 5, Edge 11 7, Edge 12 2, Edge 12 6, Edge 12 10] -- -- Demonstration code -- -- find all nodes who have an edge from 's' but not have an edge to 's' assertEqual "nodes with edge from 1 but not to 1" (let s := 1 in matchAll graphData1 as graph integer with | edge #s $x :: !(edge #x #s :: _) -> x) [4] -- find all nodes in two paths from 's' assertEqual "two-hop paths from 1" (let s := 1 in matchAll graphData1 as graph integer with | edge (#s & $x_1) $x_2 :: edge #x_2 $x_3 :: _ -> x) [{|1, 4, 3|}, {|1, 4, 3|}, {|1, 4, 3|}, {|1, 4, 3|}] -- enumerate first 5 paths from 's' to 'e' assertEqual "first 5 paths from 1 to 2" (take 5 (let s := 1 e := 2 in matchAll graphData2 as graph integer with | edge (#s & $x_1) $x_2 :: (loop $i (4, $n) (edge #x_(i - 2) $x_(i - 1) :: ...) (edge #x_(n - 1) (#e & $x_n) :: _)) -> x)) [{|1, 4, 6, 2|}, {|1, 10, 6, 2|}, {|1, 5, 9, 3, 2|}, {|1, 10, 12, 2|}, {|1, 8, 5, 9, 3, 2|}] -- find all cliques whose size is 'n' assertEqual "all 3-cliques" (let n := 3 in matchAll graphData2 as graph integer with | edge $x_1 $x_2 :: (loop $i (3, n, _) (edge #x_1 $x_i :: (loop $j (2, i - 1, _) (edge #x_j #x_i :: ...) ...)) _) -> x) [{|1, 4, 6|}, {|1, 5, 8|}, {|1, 6, 10|}, {|1, 10, 4|}, {|2, 3, 7|}, {|2, 6, 12|}, {|2, 12, 6|}, {|3, 7, 9|}, {|3, 9, 5|}, {|5, 7, 11|}, {|5, 9, 7|}, {|6, 10, 12|}, {|6, 12, 10|}] 実行