is_tree: separate VERTEX_ROOT type

igraph · Oct 27, 2023 · cb7ceda · cb7ceda
1 parent f772ee3
commit cb7ceda
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Showing 3 changed files with 21 additions and 5 deletions.
diff --git a/R/aaa-auto.R b/R/aaa-auto.R
@@ -3791,13 +3791,12 @@ is_tree_impl <- function(graph, mode=c("out", "in", "all", "total"), details=FAL
   on.exit( .Call(R_igraph_finalizer) )
   # Function call
   res <- .Call(R_igraph_is_tree, graph, mode)
-    if (!details) {
-    res <- res$res
-} else if (vcount(graph) == 0) {
-    # FIXME: Better handled in rinterface_extra.c, or via a dedicated type?
-  } else if (igraph_opt("return.vs.es")) {
+  if (igraph_opt("return.vs.es") && vcount(graph) != 0) {
     res$root <- create_vs(graph, res$root)
   }
+  if (!details) {
+    res <- res$res
+  }
   res
 }
 

diff --git a/tools/stimulus/functions-R.yaml b/tools/stimulus/functions-R.yaml
@@ -1125,6 +1125,10 @@ igraph_get_stochastic_sparsemat:
 igraph_hrg_dendrogram:
     PARAMS: OUT GRAPH graph, HRG hrg
 
+igraph_is_tree:
+    PARAMS: GRAPH graph, PRIMARY OUT BOOLEAN res, OPTIONAL OUT VERTEX_ROOT root, NEIMODE mode=OUT
+    DEPS: root ON graph
+
 #######################################
 # Coloring
 #######################################

diff --git a/tools/stimulus/types-RR.yaml b/tools/stimulus/types-RR.yaml
@@ -130,6 +130,19 @@ VERTEX:
               %I% <- create_vs(%I1%, %I%)
             }
 
+VERTEX_ROOT:
+    CALL: '%I%-1'
+    INCONV: |-
+        %I% <- as_igraph_vs(%I1%, %I%)
+        if (length(%I%) == 0) {
+          stop("No vertex was specified")
+        }
+    OUTCONV:
+        OUT: |-
+            if (igraph_opt("return.vs.es") && vcount(%I1%) != 0) {
+              %I% <- create_vs(%I1%, %I%)
+            }
+
 VERTEX_SELECTOR:
     CALL: '%I%-1'
     DEFAULT: