Initial upload

token_list.c

@@ -0,0 +1,130 @@
+/* vim: set filetype=c: */
+
+#include "token_list.h"
+
+#include <malloc.h>
+
+void TokenList_init(TokenList* obj) {
+    obj->front = NULL;
+    obj->back = NULL;
+    obj->size = 0;
+}
+
+static void TokenList_add_initial_item_(TokenList* obj, TokenListItem* data) {
+    obj->front = obj->back = data;
+    data->prev = data->next = NULL;
+    obj->size++;
+}
+
+void TokenList_push_back(TokenList* obj, TokenListItem* data) {
+    if(obj->size == 0) {
+        TokenList_add_initial_item_(obj, data);
+        return;
+    }
+    data->prev = obj->back;
+    obj->back->next = data;
+    obj->back = data;
+    data->next = NULL;
+    obj->size++;
+}
+
+
+void TokenList_push_front(TokenList* obj, TokenListItem* data) {
+    if(obj->size == 0) {
+        TokenList_add_initial_item_(obj, data);
+        return;
+    }
+    data->next = obj->front;
+    obj->front->prev = data;
+    obj->front = data;
+    data->prev = NULL;
+    obj->size++;
+}
+
+void TokenList_insert_before(TokenList* obj, TokenListItem* itm, TokenListItem* data) {
+    if(itm == obj->front) {
+        TokenList_push_front(obj, data);
+        return;
+    }
+    /* See insert_after for details */
+    data->prev = itm->prev;
+    data->next = itm;
+    itm->prev->next = data;
+    itm->prev = data;
+    obj->size++;
+}
+
+void TokenList_insert_after(TokenList* obj, TokenListItem* itm, TokenListItem* data) {
+    if(itm == obj->back) {
+        TokenList_push_back(obj, data);
+        return;
+    }
+    /* Initial state
+     * +---+ -> +---+ -> +---+
+     * |itm|    |   |    |   |
+     * +---+ <- +---+ <- +---+
+     *     +----+
+     *     |data|
+     *     +----+               */
+
+    /* Make data point to its new neighbours
+     * +---+ -> +---+ -> +---+
+     * |itm|    |   |    |   |
+     * +---+ <- +---+ <- +---+
+     *  ^          ^
+     *  |          |
+     *  |  +----+ -+
+     *  |  |data|
+     *  +- +----+               */
+    data->next = itm->next;
+    data->prev = itm;
+
+    /* Make new datas' neighbours point to it
+     * +---+ -+   +---+ -> +---+
+     * |itm|  |   |   |    |   |
+     * +---+  |   +---+ <- +---+
+     *  ^     |   |   ^
+     *  | +---+   |   |
+     *  | |       +---+--+
+     *  | |           |  |
+     *  | +-> +----+ -+  |
+     *  |     |data|     |
+     *  +---- +----+ <---+         */
+
+     /* +---+ -> +----+ -> +---+ -> +---+
+     *  |itm|    |data|    |   |    |   |
+     *  +---+ <- +----+ <- +---+ <- +---+ */
+    itm->next->prev = data;
+    itm->next = data;
+
+    obj->size++;
+}
+
+void TokenList_remove(TokenList* obj, TokenListItem* itm) {
+    if(obj->size == 1) {
+        obj->front = NULL;
+        obj->back = NULL;
+    }
+    else if(itm == obj->front) {
+        itm->next->prev = itm->prev;
+        obj->front = itm->next;
+    }
+    else if(itm == obj->back) {
+        itm->prev->next = itm->next;
+        obj->back = itm->prev;
+    } else {
+        itm->prev->next = itm->next;
+        itm->next->prev = itm->prev;
+    }
+    free(itm);
+    obj->size--;
+}
+
+void TokenList_uninit(TokenList* obj) {
+    TokenListItem* curr = obj->front;
+    while(curr != NULL) {
+        TokenListItem* next = curr->next;
+        free(curr);
+        curr = next;
+    }
+}