libds

commit 14b7a734b4a11d12aaec3addbd5cdc062b5c1768
parent 1c6a976146697d192bdbf4f16abf37ee6a6f0fcf
Author: sin <sin@2f30.org>
Date:   Tue,  6 May 2014 13:09:23 +0100

Add simple stack implementation

Diffstat:
M
Makefile
 | 
2
+-
M
ds.h
 | 
19
+++++++++++++------
A
stack.c
 | 
72
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 86 insertions(+), 7 deletions(-)
diff --git a/Makefile b/Makefile
@@ -3,7 +3,7 @@
 
 include config.mk
 
-SRC = vector.c fifo.c
+SRC = fifo.c stack.c vector.c
 OBJ = ${SRC:.c=.o}
 SOUT = ${NAME}.a
 
diff --git a/ds.h b/ds.h
@@ -3,6 +3,19 @@
 
 #include <stddef.h>
 
+/* fifo.c */
+struct fifo *fifo_init(size_t);
+void fifo_free(struct fifo *);
+int fifo_add(struct fifo *, const void *, size_t);
+int fifo_remove(struct fifo *, void *, size_t);
+
+/* stack.c */
+struct stack *stack_init(void);
+void stack_free(struct stack *);
+void *stack_push(struct stack *, void *);
+void *stack_pop(struct stack *);
+void *stack_peek(struct stack *);
+
 /* vector.c */
 struct vector *vector_init(void);
 void vector_free(struct vector *);
@@ -11,10 +24,4 @@ void *vector_get(struct vector *, size_t);
 size_t vector_len(struct vector *);
 void vector_walk(struct vector *, void (*)(struct vector *, void *));
 
-/* fifo.c */
-struct fifo *fifo_init(size_t);
-void fifo_free(struct fifo *);
-int fifo_add(struct fifo *, const void *, size_t)
-int fifo_remove(struct fifo *, void *, size_t);
-
 #endif
diff --git a/stack.c b/stack.c
@@ -0,0 +1,72 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+struct stacknode {
+	void *data;
+	struct stacknode *next;
+};
+
+struct stack {
+	struct stacknode *top;
+};
+
+struct stack *
+stack_init(void)
+{
+	struct stack *s;
+
+	s = calloc(1, sizeof(*s));
+	if (!s)
+		return NULL;
+	return s;
+}
+
+void
+stack_free(struct stack *s)
+{
+	struct stacknode *n, *tmp;
+
+	if (s->top) {
+		n = s->top;
+		while (n) {
+			tmp = n->next;
+			free(tmp);
+			n = tmp;
+		}
+	}
+	free(s);
+}
+
+void *
+stack_push(struct stack *s, void *data)
+{
+	struct stacknode *n;
+
+	n = calloc(1, sizeof(*n));
+	if (!n)
+		return NULL;
+	n->data = data;
+	n->next = s->top;
+	s->top = n;
+	return data;
+}
+
+void *
+stack_pop(struct stack *s)
+{
+	void *data;
+
+	if (!s->top)
+		return NULL;
+	data = s->top->data;
+	s->top = s->top->next;
+	return data;
+}
+
+void *
+stack_peek(struct stack *s)
+{
+	if (!s->top)
+		return NULL;
+	return s->top->data;
+}