From bfabb435e5c5bf313005c4636747fce59eb4ca6f Mon Sep 17 00:00:00 2001
From: 3gg <3gg@shellblade.net>
Date: Mon, 12 Jun 2023 08:52:15 -0700
Subject: Add list library.

---
 list/include/list.h | 118 +++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 104 insertions(+), 14 deletions(-)

(limited to 'list/include')

diff --git a/list/include/list.h b/list/include/list.h
index 945de28..facf820 100644
--- a/list/include/list.h
+++ b/list/include/list.h
@@ -1,21 +1,111 @@
-/// A doubly linked list.
-///
-/// This list does not hold user data. Instead, the list can be used as an
-/// intrusive list or as part as a more complex data structure.
+/// Doubly-linked list.
 #pragma once
 
+#include <assert.h>
 #include <stddef.h>
+#include <stdlib.h>
+
+#define DEF_LIST(type)         \
+  typedef struct type##_node { \
+    type                val;   \
+    struct type##_node* prev;  \
+    struct type##_node* next;  \
+  } type##_node;               \
+  typedef struct type##_list { \
+    type##_node* head;         \
+  } type##_list;
+
+static inline void* alloc(size_t size) {
+  void* ptr = calloc(1, size);
+  assert(ptr);
+  return ptr;
+}
+
+/// Create a new empty list.
+#define make_list(type) \
+  (type##_list) { 0 }
+
+/// Delete the list.
+#define del_list(list)                                  \
+  for (__typeof__(list.head) node = list.head; node;) { \
+    __typeof__(node) cur = node;                        \
+    node                 = node->next;                  \
+    free(cur);                                          \
+  }                                                     \
+  list.head = 0;
 
-typedef struct list list;
+/// Prepend a value to the list.
+#define list_push(list, value)                              \
+  {                                                         \
+    __typeof__(list.head) node = alloc(sizeof(*list.head)); \
+    node->val                  = value;                     \
+    node->next                 = list.head;                 \
+    if (list.head) {                                        \
+      list.head->prev = node;                               \
+    }                                                       \
+    list.head = node;                                       \
+  }
 
-typedef struct list {
-  list* prev;
-  list* next;
-} list;
+/// Delete the first occurrence of the value from the list.
+#define list_remove(list, search_value)                                   \
+  for (__typeof__(list.head) iter = list.head; iter; iter = iter->next) { \
+    if (iter->val == (search_value)) {                                    \
+      del_node(list, iter);                                               \
+      break;                                                              \
+    }                                                                     \
+  }
 
-/// Create a new list from an array of `size` items.
-void list_make(list* list, size_t size);
+/// Delete the node that contains the value at the given address from the
+/// list.
+#define list_remove_ptr(list, value_ptr)                                  \
+  for (__typeof__(list.head) iter = list.head; iter; iter = iter->next) { \
+    if (&iter->val == value_ptr) {                                        \
+      del_node(list, iter);                                               \
+      break;                                                              \
+    }                                                                     \
+  }
 
-/// Iterates over all the items in the list.
-#define list_foreach(LIST, iter) \
-  for (struct list* iter = LIST; iter; iter = iter->next)
+/// Delete the list node.
+#define del_node(list, node)         \
+  {                                  \
+    assert(node);                    \
+    if (node->prev) {                \
+      node->prev->next = node->next; \
+    }                                \
+    if (node->next) {                \
+      node->next->prev = node->prev; \
+    }                                \
+    if (list.head == node) {         \
+      list.head = 0;                 \
+    }                                \
+    free(node);                      \
+    node = 0;                        \
+  }
+
+/// Iterate over all the items in the list.
+///
+/// Use 'value' to refer to the address of the current node's value during
+/// iteration.
+#define list_foreach(list, body)                       \
+  {                                                    \
+    __typeof__(list.head) node = list.head;            \
+    while (node) {                                     \
+      const __typeof__(node->val)* value = &node->val; \
+      body;                                            \
+      node = node->next;                               \
+    }                                                  \
+  }
+
+/// Iterate over all the items in the list.
+///
+/// Use 'value' to refer to the address of the current node's value during
+/// iteration.
+#define list_foreach_mut(list, body)             \
+  {                                              \
+    __typeof__(list.head) node = list.head;      \
+    while (node) {                               \
+      __typeof__(node->val)* value = &node->val; \
+      body;                                      \
+      node = node->next;                         \
+    }                                            \
+  }
-- 
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