The graph-dfs library is an implementation of depth-first search on a graph object that follows the API of e.g. the digraph egg.
depth-first search iterator; given a list of initial nodes, ROOTS, the successors of each initial node are visited in depth-first search order, and procedures FNODE and FEDGE are applied to each node or edge, respectively, as the graph is traversed. FNODE is of the form LAMBDA N -> _ where N is node number; and FEDGE is of the form LAMBDA EDGE where EDGE is a list of the form (I J INFO); I and J are the nodes defining the edge, and INFO is edge metadata.
depth-first search iterator with state; given a list of initial nodes, ROOTS, and initial node state and edge state, NODE-INIT and EDGE-INIT the successors of each initial node are visited in depth-first search order, and procedures FNODE and FEDGE are applied to each node and the node state, or edge and the edge state, respectively, as the graph is traversed. FNODE is of the form LAMBDA N NODE-STATE -> NODE-STATE where N is node number, and NODE-STATE can be of arbitrary type and must of the same type as NODE-INIT. FEDGE is of the form LAMBDA EDGE EDGE-STATE where EDGE is a list of the form (I J INFO); I and J are the nodes defining the edge, and INFO is edge metadata; EDGE-STATE must be of the same type as EDGE-INIT
depth-first search depth; given a list of initial nodes, this procedure computes shortest DFS depth for each nodes traversed, and the number of nodes visited while traversing the successors of each node. NODE-DEPTH is an array that contains the corresponding DFS depth for each node; TRAVERSAL-TIME is also an array, where each value is the number of nodes visited in the sub-graph of that node.
compute the preorder traversal sequence number for each successor of the given initial node.
compute the postorder traversal sequence number for each successor of the given initial node.
;; example adapted from graph example in the Boost library documentation (require-extension srfi-1) (require-extension digraph) (require-extension graph-dfs) (define g (make-digraph 'depgraph "dependency graph")) (define used-by (list (cons 'dax_h 'foo_cpp) (cons 'dax_h 'bar_cpp) (cons 'dax_h 'yow_h) (cons 'yow_h 'bar_cpp) (cons 'yow_h 'zag_cpp) (cons 'boz_h 'bar_cpp) (cons 'boz_h 'zig_cpp) (cons 'boz_h 'zag_cpp) (cons 'zow_h 'foo_cpp) (cons 'foo_cpp 'foo_o) (cons 'foo_o 'libfoobar_a) (cons 'bar_cpp 'bar_o) (cons 'bar_o 'libfoobar_a) (cons 'libfoobar_a 'libzigzag_a) (cons 'zig_cpp 'zig_o) (cons 'zig_o 'libzigzag_a) (cons 'zag_cpp 'zag_o) (cons 'zag_o 'libzigzag_a) (cons 'libzigzag_a 'killerapp))) (define node-list (delete-duplicates (concatenate (list (map car used-by) (map cdr used-by))))) (define node-ids (list-tabulate (length node-list) values)) (for-each (lambda (i n) ((g 'add-node!) i n)) node-ids node-list) (define node-map (zip node-list node-ids)) (for-each (lambda (e) (match e ((ni . nj) (let ((i (car (alist-ref ni node-map))) (j (car (alist-ref nj node-map)))) ((g 'add-edge!) (list i j (format "~A->~A" ni nj))))) (else (error "invalid edge " e)))) used-by) (define roots (map car ((g 'roots)))) (graph-dfs-foreach g (lambda (n) (print (format "node ~A; " n))) (lambda (e) (print (format "edge ~A; " e))) roots) (graph-dfs-fold g (lambda (n ax) (cons (list 'node n) ax)) (lambda (e ax) (cons (list 'edge e) ax)) roots (list) (list))
Copyright Ivan Raikov and the Okinawa Institute of Science and Technology This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. A full copy of the GPL license can be found at <http://www.gnu.org/licenses/>.