Initial commit

.gitignore

@@ -0,0 +1,2 @@
+build
+.cache

Makefile

@@ -0,0 +1,10 @@
+BUILDDIR="build"
+
+all: configure
+	meson compile -C $(BUILDDIR)
+
+configure:
+	meson setup $(BUILDDIR)
+
+test: configure
+	meson test -vC $(BUILDDIR)

include/doubly-linked-list.h

@@ -0,0 +1,43 @@
+struct dll_node {
+  struct dll_node *previous;
+  struct dll_node *next;
+  char *value;
+};
+
+typedef struct dll_node dll_node;
+
+typedef struct {
+  struct dll_node *head;
+} dll_list;
+
+/**
+ * Allocates a new (empty) doubly linked list
+ */
+dll_list *dll_list_new();
+
+/**
+ * Frees the memory used by a list, including all of its child nodes
+ */
+void dll_list_free(dll_list *list);
+
+/**
+ * Inserts a given node at the given index of the given list. If index is -1
+*  or is greater than the size of the list, then the node will be inserted at the end of the list
+ */
+void dll_list_insert(dll_list *list, dll_node *node, int index);
+
+/**
+ * Appends a node to the end of a given list
+ */
+void dll_list_append(dll_list *list, dll_node *node) {
+  dll_list_insert(list, node, -1);
+}
+
+// TODO: find and delete operations on list
+
+dll_node *dll_node_new(char *value);
+
+/**
+ * Frees the memory for a given node, returning a pointer to the next node, if any
+ */
+dll_node *dll_node_free(dll_node *node);

meson.build

@@ -0,0 +1,5 @@
+project('clox', 'c')
+incdir = include_directories('include')
+dll_lib = library('dll', 'src/doubly-linked-list.c', include_directories: incdir)
+dll_test = executable('dll_test', 'test/dll.c', include_directories: incdir, link_with: dll_lib)
+test('doubly-linked list tests', dll_test)

src/doubly-linked-list.c

@@ -0,0 +1,72 @@
+#include "doubly-linked-list.h"
+#include <stdatomic.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+dll_list *dll_list_new() {
+  dll_list *list = malloc(sizeof(dll_list));
+  list->head = NULL;
+  return list;
+}
+
+void dll_list_free(dll_list *list) {
+  dll_node *current_node = list->head;
+  while (current_node != NULL) {
+    current_node = dll_node_free(current_node);
+  }
+
+  free(list);
+}
+
+void dll_list_insert(dll_list *list, dll_node *node, int index) {
+  if (list->head == NULL) {
+    list->head = node;
+    return;
+  }
+
+  if (index == 0) {
+    dll_node *old_head = list->head;
+    list->head = node;
+    node->next = old_head;
+    return;
+  }
+
+  int current_index = 0;
+  dll_node *current_node = list->head;
+  while (current_node->next != NULL) {
+    current_index++;
+    if (index > -1 && index == current_index) {
+      break;
+    }
+    current_node = current_node->next;
+  }
+  dll_node *next_node = current_node->next;
+  if (next_node != NULL) {
+    next_node->previous = node;
+    node->next = next_node;
+  }
+  node->previous = current_node;
+  current_node->next = node;
+}
+
+dll_node *dll_node_new(char *value) {
+  dll_node *node = malloc(sizeof(dll_node));
+  node->previous = NULL;
+  node->next = NULL;
+  int value_length = strlen(value) * sizeof(char);
+  value_length++; // pad for null byte
+  node->value = malloc(value_length);
+  strcpy(node->value, value);
+  node->value[value_length - 1] = '\0';
+  return node;
+}
+
+dll_node *dll_node_free(dll_node *node) {
+  dll_node *next = node->next;
+  free(node->value);
+  node->previous = NULL;
+  node->next = NULL;
+  free(node);
+  return next;
+}

test/dll.c

@@ -0,0 +1,93 @@
+#include "doubly-linked-list.h"
+#include <stdatomic.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+dll_list *list = NULL;
+dll_node *head = NULL;
+char *list_string = NULL;
+
+#define ASSERT_STR_EQ(expected, actual)                                        \
+  {                                                                            \
+    if (strcmp(expected, actual) != 0) {                                       \
+      fprintf(stderr,                                                          \
+              "strings don't match. expected: \"%s\", actual: \"%s\"\n",       \
+              expected, actual);                                               \
+      cleanup();                                                               \
+      return 1;                                                                \
+    }                                                                          \
+  }
+
+char *list_to_string(dll_list *list) {
+  char *list_string = malloc(sizeof(char));
+  list_string[0] = '\0';
+  dll_node *current_node = list->head;
+  while (current_node != NULL) {
+    // TODO: There's probably a better way to do this. Find it
+    int list_string_length = strlen(list_string);
+    int new_length = list_string_length + strlen(current_node->value) + 1;
+    if (current_node->previous != NULL) {
+      new_length += 2; // Add space for another ", "
+    }
+    char *new_list_string = realloc(list_string, new_length);
+    if (new_list_string == NULL) {
+      fprintf(stderr, "error: failed to reallocate memory for list string\n");
+      return NULL;
+    } else {
+      list_string = new_list_string;
+    }
+    if (list_string_length > 0 && current_node->previous != NULL) {
+      strcpy(&list_string[list_string_length], ", ");
+      list_string_length += 2;
+    }
+    strcpy(&list_string[list_string_length], current_node->value);
+    list_string[new_length - 1] = '\0';
+    current_node = current_node->next;
+  }
+  return list_string;
+}
+
+void cleanup() {
+  if (list != NULL) {
+    dll_list_free(list);
+    list = NULL;
+  }
+
+  if (head != NULL) {
+    dll_node_free(head);
+    head = NULL;
+  }
+
+  if (list_string != NULL) {
+    free(list_string);
+    list_string = NULL;
+  }
+}
+
+int main(int argc, char **argv) {
+  list = dll_list_new();
+  dll_node *head = dll_node_new("0");
+  dll_list_append(list, head);
+  head = NULL;
+  // TODO: Extract test utilities to shared file
+  list_string = list_to_string(list);
+  ASSERT_STR_EQ("0", list_string);
+
+  dll_node *third = dll_node_new("2");
+  dll_list_insert(list, third, 2);
+
+  free(list_string);
+  list_string = list_to_string(list);
+  ASSERT_STR_EQ("0, 2", list_string);
+
+  dll_node *second = dll_node_new("1");
+  dll_list_insert(list, second, 1);
+
+  free(list_string);
+  list_string = list_to_string(list);
+  ASSERT_STR_EQ("0, 1, 2", list_string);
+
+  cleanup();
+  return 0;
+}