From de41cfb61d4cbafdc3ffe8a2651630a53b3c8d11 Mon Sep 17 00:00:00 2001
From: Tucker Evans <tuckerevans24@gmail.com>
Date: Fri, 24 Jul 2020 15:56:43 -0400
Subject: Add first/last getters for maps.

---
 collections/map/map.adoc | 49 ++++++++++++++++++++++++++++++++++++++++++++++++
 collections/map/map.c    | 24 ++++++++++++++++++++++++
 collections/map/map.h    |  3 +++
 3 files changed, 76 insertions(+)

diff --git a/collections/map/map.adoc b/collections/map/map.adoc
index 740df3c..690aa3d 100644
--- a/collections/map/map.adoc
+++ b/collections/map/map.adoc
@@ -119,6 +119,55 @@ assert(strcmp(tmp, "FOUR") == 0);
 free(tmp);
 ----
 
+[[map_first]]
++void* map_first(map *self)+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Returns the value associated with the smallest key from +self+.
+
+Examples
+^^^^^^^^
+[source,c]
+----
+#include "map.h"
+#include <string.h>
+
+char *str1 = "A";
+char *str2 = "Z";
+
+map *dict = map_new((cmp_func) strcmp);
+
+map_insert(dict, str1, str1);
+map_insert(dict, str2, str2);
+
+
+assert(strcmp(str1, map_first(dict) == 0);
+----
+
+[[map_last]]
++void* map_last(map *self)+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Returns the value associated with the largest key from +self+.
+
+Examples
+^^^^^^^^
+[source,c]
+----
+#include "map.h"
+#include <string.h>
+
+char *str1 = "A";
+char *str2 = "Z";
+
+map *dict = map_new((cmp_func) strcmp);
+
+map_insert(dict, str1, str1);
+map_insert(dict, str2, str2);
+
+
+assert(strcmp(str2, map_last(dict) == 0);
+----
+
+
 [[map_swap]]
 +void map_swap(map *self, void *i, void *j)+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/collections/map/map.c b/collections/map/map.c
index b0e095e..d581d81 100644
--- a/collections/map/map.c
+++ b/collections/map/map.c
@@ -497,6 +497,30 @@ void *key;
 	return ret;
 }
 
+void* map_first(root)
+map *root;
+{
+	struct map_node *tmp;
+
+	if (!root)
+		return;
+
+	for (tmp = root->root; tmp->left; tmp = tmp->left);
+	return tmp->val;
+}
+
+void* map_last(root)
+map *root;
+{
+	struct map_node *tmp;
+
+	if (!(root || root->root))
+		return;
+
+	for (tmp = root->root; tmp->right; tmp = tmp->right);
+	return tmp->val;
+}
+
 void map_swap(root, ikey, jkey)
 map *root;
 void *ikey, *jkey;
diff --git a/collections/map/map.h b/collections/map/map.h
index c6fb83d..b3ea4c5 100644
--- a/collections/map/map.h
+++ b/collections/map/map.h
@@ -14,6 +14,9 @@ int map_size(map*);
 int map_insert(map*, void*, void*);
 void* map_remove(map*, void*);
 
+void* map_first(map*);
+void* map_last(map*);
+
 void* map_set_val(map*, void*, void*);
 void* map_index(map*, void*);
 
-- 
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