From 5cbd188b8081d74f422edf8b14427c14c0dc8c0e Mon Sep 17 00:00:00 2001
From: XANTRONIX Development <dev@xantronix.com>
Date: Wed, 10 Jan 2024 23:31:45 -0500
Subject: [PATCH] Initial implementation of hexagram_list

---
 include/hexagram/list.h | 26 ++++++++++++++
 src/Makefile            | 12 +++----
 src/list.c              | 78 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 110 insertions(+), 6 deletions(-)
 create mode 100644 include/hexagram/list.h
 create mode 100644 src/list.c

diff --git a/include/hexagram/list.h b/include/hexagram/list.h
new file mode 100644
index 0000000..e4c6c17
--- /dev/null
+++ b/include/hexagram/list.h
@@ -0,0 +1,26 @@
+#ifndef _HEXAGRAM_LIST_H
+#define _HEXAGRAM_LIST_H
+
+#include <sys/types.h>
+
+typedef struct _hexagram_list_item {
+    void *obj;
+    struct _hexagram_list_item *next;
+} hexagram_list_item;
+
+typedef struct _hexagram_list {
+    size_t count;
+
+    hexagram_list_item *head,
+                       *tail;
+} hexagram_list;
+
+hexagram_list *hexagram_list_new(void);
+
+void hexagram_list_destroy(hexagram_list *list);
+
+int hexagram_list_item_add(hexagram_list *list, void *obj);
+
+void *hexagram_list_item_get(hexagram_list *list, size_t index);
+
+#endif /* _HEXAGRAM_LIST_H */
diff --git a/src/Makefile b/src/Makefile
index 5654c62..f527c6c 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -7,15 +7,15 @@ CC		= $(CROSS)cc
 CFLAGS		+= -fPIC -I$(INCLUDE_PATH) $(shell pkg-config --cflags cairo x11)
 LDFLAGS		= $(shell pkg-config --libs cairo x11) -lXext
 
-HEADERS		= dict.h hash.h can.h capture.h pcapng.h module.h window.h \
-		  gauge.h tacho.h speedo.h thermo.h fuel.h mfd.h cluster.h \
-		  sim.h schedule.h
+HEADERS		= list.h dict.h hash.h can.h capture.h pcapng.h module.h \
+		  window.h gauge.h tacho.h speedo.h thermo.h fuel.h mfd.h \
+		  cluster.h sim.h schedule.h
 
 HEADERS_LOCAL	= util.h
 
-OBJS		= dict.o hash.o can.o capture.o pcapng.o module.o window.o \
-		  gauge.o tacho.o speedo.o thermo.o fuel.o mfd.o cluster.o \
-		  sim.o schedule.o
+OBJS		= list.o dict.o hash.o can.o capture.o pcapng.o module.o \
+		  window.o gauge.o tacho.o speedo.o thermo.o fuel.o mfd.o \
+		  cluster.o sim.o schedule.o
 
 VERSION_MAJOR	= 0
 VERSION_MINOR	= 0.1
diff --git a/src/list.c b/src/list.c
new file mode 100644
index 0000000..15bed3d
--- /dev/null
+++ b/src/list.c
@@ -0,0 +1,78 @@
+#include <stdlib.h>
+
+#include <hexagram/list.h>
+
+hexagram_list *hexagram_list_new(void) {
+    hexagram_list *list;
+
+    if ((list = malloc(sizeof(*list))) == NULL) {
+        goto error_malloc_list;
+    }
+
+    list->count = 0;
+    list->head  = NULL;
+    list->tail  = NULL;
+
+    return list;
+
+error_malloc_list:
+    return NULL;
+}
+
+void hexagram_list_destroy(hexagram_list *list) {
+    hexagram_list_item *cur = list->head;
+
+    while (cur) {
+        hexagram_list_item *next = cur->next;
+
+        free(cur);
+
+        cur = next;
+    }
+
+    free(list);
+}
+
+int hexagram_list_item_add(hexagram_list *list, void *obj) {
+    hexagram_list_item *item;
+
+    if ((item = malloc(sizeof(*item))) == NULL) {
+        goto error_malloc_item;
+    }
+
+    item->obj  = obj;
+    item->next = NULL;
+
+    if (list->head == NULL) {
+        list->head = item;
+        list->tail = item;
+    } else {
+        list->tail->next = item;
+        list->tail       = item;
+    }
+
+    return 0;
+
+error_malloc_item:
+    return -1;
+}
+
+void *hexagram_list_item_get(hexagram_list *list, size_t index) {
+    hexagram_list_item *cur;
+    size_t i;
+
+    if (index > list->count) {
+        goto error_bounds;
+    }
+
+    cur = list->head;
+
+    for (i=0; i<index; i++) {
+        cur = cur->next;
+    }
+
+    return cur->obj;
+
+error_bounds:
+    return NULL;
+}