feat: Adds find_path_one_to_many

DESCRIPTION

@@ -23,7 +23,7 @@ BugReports: https://github.com/ixpantia/orbweaver-r/issues
 License: MIT + file LICENSE
 Encoding: UTF-8
 Roxygen: list(markdown = TRUE)
-RoxygenNote: 7.3.1
+RoxygenNote: 7.3.2
 Config/rextendr/version: 0.3.1.9000
 SystemRequirements: Cargo (Rust's package manager) >= 1.70, rustc >= 1.70
 Depends:

NAMESPACE

@@ -15,6 +15,8 @@ S3method(find_all_paths,DirectedAcyclicGraph)
 S3method(find_all_paths,DirectedGraph)
 S3method(find_path,DirectedAcyclicGraph)
 S3method(find_path,DirectedGraph)
+S3method(find_path_one_to_many,DirectedAcyclicGraph)
+S3method(find_path_one_to_many,DirectedGraph)
 S3method(get_all_leaves,DirectedAcyclicGraph)
 S3method(get_all_leaves,DirectedGraph)
 S3method(get_all_roots,DirectedAcyclicGraph)
@@ -47,6 +49,7 @@ export(build_directed)
 export(children)
 export(find_all_paths)
 export(find_path)
+export(find_path_one_to_many)
 export(get_all_leaves)
 export(get_all_roots)
 export(get_leaves_under)

R/extendr-wrappers.R

@@ -52,6 +52,8 @@ DirectedGraph$length <- function() .Call(wrap__DirectedGraph__length, self)
 
 DirectedGraph$find_all_paths <- function(from, to) .Call(wrap__DirectedGraph__find_all_paths, self, from, to)
 
+DirectedGraph$find_path_one_to_many <- function(from, to) .Call(wrap__DirectedGraph__find_path_one_to_many, self, from, to)
+
 #' @export
 `$.DirectedGraph` <- function (self, name) { func <- DirectedGraph[[name]]; environment(func) <- environment(); func }
 
@@ -98,6 +100,8 @@ DirectedAcyclicGraph$length <- function() .Call(wrap__DirectedAcyclicGraph__leng
 
 DirectedAcyclicGraph$find_all_paths <- function(from, to) .Call(wrap__DirectedAcyclicGraph__find_all_paths, self, from, to)
 
+DirectedAcyclicGraph$find_path_one_to_many <- function(from, to) .Call(wrap__DirectedAcyclicGraph__find_path_one_to_many, self, from, to)
+
 #' @export
 `$.DirectedAcyclicGraph` <- function (self, name) { func <- DirectedAcyclicGraph[[name]]; environment(func) <- environment(); func }
 

R/find_path.R

@@ -53,3 +53,29 @@ find_all_paths.DirectedGraph <- function(graph, from, to) {
 find_all_paths.DirectedAcyclicGraph <- function(graph, from, to) {
   graph$find_all_paths(from, to)
 }
+
+#' @title Find the shortest path from one node to many
+#'
+#' @description
+#' Find the shortest path from one node to many
+#'
+#' Not all graphs support this function. Currently only
+#' `DirectedAcyclicGraph` supports this.
+#' @param graph A graph object
+#' @param from The starting node of the path
+#' @param to A character vector of nodes
+#' @return A list of paths
+#' @export
+find_path_one_to_many <- function(graph, from, to) {
+  UseMethod("find_path_one_to_many")
+}
+
+#' @export
+find_path_one_to_many.DirectedGraph <- function(graph, from, to) {
+  graph$find_path_one_to_many(from, to)
+}
+
+#' @export
+find_path_one_to_many.DirectedAcyclicGraph <- function(graph, from, to) {
+  graph$find_path_one_to_many(from, to)
+}

src/rust/src/lib.rs

@@ -134,6 +134,7 @@ impl DirectedGraphBuilder {
 
 pub trait RImplDirectedGraph: Sized {
     fn find_path(&self, from: &str, to: &str) -> Result<NodeVec>;
+    fn find_path_one_to_many(&self, from: &str, to: Strings) -> Result<List>;
     fn children(&self, nodes: RNodesIn) -> Result<NodeVec>;
     fn parents(&self, nodes: RNodesIn) -> Result<NodeVec>;
     fn has_parents(&self, nodes: RNodesIn) -> Result<Vec<bool>>;

src/rust/src/macros.rs

@@ -99,6 +99,16 @@ macro_rules! impl_directed_graph {
                     .map(NodeVec)
                     .collect())
             }
+
+            fn find_path_one_to_many(&self, from: &str, to: Strings) -> Result<List> {
+                Ok(self
+                    .0
+                    .find_path_one_to_many(from, to.iter())
+                    .map_err(to_r_error)?
+                    .into_iter()
+                    .map(NodeVec)
+                    .collect())
+            }
         }
 
         impl $ty {

tests/testthat/test-find_path.R

@@ -22,3 +22,37 @@ test_that("find all paths on directed acyclic graph", {
     list(c("A", "Z", "C"), c("A", "B", "C"))
   )
 })
+
+test_that("find path from one node to many nodes", {
+
+  edges <- tibble::tibble(
+    Parent = c("A", "A", "B", "C", "D", "Z"),
+    Child = c("B", "C", "Z", "D", "Z", "F")
+  )
+
+  graph <- graph_builder() |>
+    populate_edges(edges, Parent, Child) |>
+    build_acyclic()
+
+  edges$path_ow <- find_path_one_to_many(graph, "A", edges$Child)
+  edges$level <- sapply(edges$path_ow, length)
+  edges$path <- sapply(edges$path_ow, \(path) paste(as.character(path), collapse = "|"))
+
+  expect_equal(
+    edges$level,
+    c(2, 2, 5, 3, 5, 6)
+  )
+
+  expect_equal(
+    edges$path,
+    c(
+      "A|B",
+      "A|C",
+      "A|B|C|D|Z",
+      "A|C|D",
+      "A|B|C|D|Z",
+      "A|B|C|D|Z|F"
+    )
+  )
+
+})