From: David Given <dg@cowlark.com>
Date: Mon, 28 Nov 2016 22:38:01 +0000 (+0100)
Subject: Add a routine for adding bidirectional edges to a graph.
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=1b6e7e1bb660579479cef264205874730762f911;p=ack.git

Add a routine for adding bidirectional edges to a graph.
---

diff --git a/modules/src/data/pmap.c b/modules/src/data/pmap.c
index fffba7e90..4ac38178a 100644
--- a/modules/src/data/pmap.c
+++ b/modules/src/data/pmap.c
@@ -57,6 +57,22 @@ void pmap_add(void* mapp, void* left, void* right)
     append(map, left, right);
 }
 
+void pmap_add_bi(void* mapp, void* left, void* right)
+{
+    struct pmap* map = mapp;
+    int i;
+
+    for (i=0; i<map->count; i++)
+    {
+        struct pmap_node* node = &map->item[i];
+        if (((node->left == left) && (node->right == right)) ||
+            ((node->left == right) && (node->right == left)))
+            return;
+    }
+
+    append(map, left, right);
+}
+
 void pmap_remove(void* mapp, void* left, void* right)
 {
     struct pmap* map = mapp;
diff --git a/modules/src/data/pmap.h b/modules/src/data/pmap.h
index a7980a3a3..ff43b6aa3 100644
--- a/modules/src/data/pmap.h
+++ b/modules/src/data/pmap.h
@@ -25,6 +25,7 @@ struct pmap
 
 extern void pmap_put(void* map, void* left, void* right);
 extern void pmap_add(void* map, void* left, void* right);
+extern void pmap_add_bi(void* map, void* left, void* right);
 extern void pmap_remove(void* map, void* left, void* right);
 extern void* pmap_findleft(void* map, void* left);
 extern void* pmap_findright(void* map, void* right);