Add remove function for vectors

Removes element at an index.

3 files changed, 47 insertions, 1 deletions

diff --git a/collections/vector/vector.adoc b/collections/vector/vector.adoc
index 9e61a43..d423c37 100644
--- a/collections/vector/vector.adoc
+++ b/collections/vector/vector.adoc
@@ -1,7 +1,7 @@
 Vector
 ======
 Tucker Evans
-v0.13, 2020-07-03
+v0.14, 2020-07-03
 
 A basic vector, that hold pointers to your data structures.
 
@@ -284,6 +284,35 @@ assert(str_cmp(vec_index(vector, 1), str3) == 0);
 assert(str_cmp(vec_index(vector, 2), str2) == 0);
 ----
 
+[[vec_remove]]
++void vec_remove(vec *self, int index)+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Element at position +index+ of +self+ is removed from vector and the remaining
+items are shifted towards the front.
+
+Examples
+^^^^^^^^
+[source,c]
+----
+#include "vector.h"
+#include <string.h>
+
+char *str1 = "ONE";
+char *str2 = "TWO";
+char *str3 = "THREE";
+
+vec *vector = vec_new();
+vec_push(vector, str_dup(str1));
+vec_push(vector, str_dup(str2));
+vec_push(vector, str_dup(str3));
+
+vec_remove(vector, 1);
+
+assert(vec_size == 2);
+assert(strcmp(vec_pop(vector), str3) == 0);
+assert(strcmp(vec_pop(vector), str1) == 0);
+----
+
 [[vec_swap]]
 +void vec_swap(vec *self, int i, int j)+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/collections/vector/vector.c b/collections/vector/vector.c
index 2ae748f..5c473a4 100644
--- a/collections/vector/vector.c
+++ b/collections/vector/vector.c
@@ -191,6 +191,22 @@ void *item;
 	root->base[index] = item;
 }
 
+void* vec_remove(root, index)
+vec *root;
+int index;
+{
+	void *tmp;
+
+	if (!root || index > root->end || index < 0)
+		return NULL;
+
+	tmp = vec_index(root, index);
+	memmove(root->base + index, root->base + index + 1,
+			(--root->end - index) * sizeof(void*));
+
+	return tmp;
+}
+
 void vec_swap(root, i, j)
 vec *root;
 int i,j;
diff --git a/collections/vector/vector.h b/collections/vector/vector.h
index 1b47642..083a1d0 100644
--- a/collections/vector/vector.h
+++ b/collections/vector/vector.h
@@ -22,6 +22,7 @@ void vec_set(vec*, int, void*);
 void* vec_index(vec*, int);
 
 void vec_insert(vec*, int, void*);
+void* vec_remove(vec*, int);
 
 void vec_swap(vec*, int, int);
 void* vec_swap_pop(vec*, int);