utils: Create linked list data structure

This is a simple implementation of a general propose single-linked list.

There is only the *prepend* function implemented at this moment.  We can
alway revisit the code and implement new missing functionality on demand.

Signed-off-by: Johnny Richard <johnny@johnnyrichard.com>

4 files changed, 176 insertions, 0 deletions

diff --git a/src/list.c b/src/list.c
new file mode 100644
index 0000000..b73280f
--- /dev/null
+++ b/src/list.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2023 Johnny Richard
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#include "list.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static list_t *
+list_alloc(void)
+{
+  list_t *list = (list_t *)malloc(sizeof(list_t));
+  if (list == NULL) {
+    fprintf(stderr, "list_alloc: Out of memory %s\n", strerror(errno));
+    exit(EXIT_FAILURE);
+  }
+  return list;
+}
+
+list_t *
+list_new(void)
+{
+  return NULL;
+}
+
+void
+list_prepend(list_t **list, void *data)
+{
+  list_t *new_list = list_alloc();
+  new_list->data = data;
+  new_list->next = *list;
+  *list = new_list;
+}
+
+size_t
+list_get_size(list_t *list)
+{
+  size_t size = 0;
+  while (list != NULL) {
+    list = list->next;
+    size++;
+  }
+  return size;
+}
+
+void
+list_destroy(list_t *list)
+{
+  while (list != NULL) {
+    list_t *previous = list;
+    list = list->next;
+    free(previous);
+  }
+}
diff --git a/src/list.h b/src/list.h
new file mode 100644
index 0000000..efe5720
--- /dev/null
+++ b/src/list.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2023 Johnny Richard
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#ifndef LIST_H
+#define LIST_H
+
+#include <stdlib.h>
+
+typedef struct list_t
+{
+  void *data;
+  struct list_t *next;
+} list_t;
+
+list_t *
+list_new(void);
+
+void
+list_prepend(list_t **list, void *data);
+
+size_t
+list_get_size(list_t *list);
+
+void
+list_destroy(list_t *list);
+
+#endif /* LIST_H */
diff --git a/test/Makefile b/test/Makefile
index 1655f06..6bdec12 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -28,6 +28,9 @@ string_view_test: munit.o ../build/string_view.o string_view_test.o
 vector_test: munit.o ../build/vector.o vector_test.o
 	$(CC) $? $(CFLAGS) -o $@
 
+list_test: munit.o ../build/list.o list_test.o
+	$(CC) $? $(CFLAGS) -o $@
+
 lexer_test: munit.o ../build/string_view.o ../build/lexer.o lexer_test.o
 	$(CC) $? $(CFLAGS) -o $@
 
diff --git a/test/list_test.c b/test/list_test.c
new file mode 100644
index 0000000..041ceec
--- /dev/null
+++ b/test/list_test.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2023 Johnny Richard
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#define MUNIT_ENABLE_ASSERT_ALIASES
+#include "list.h"
+#include "munit.h"
+
+static MunitResult
+test_create_new(const MunitParameter params[], void *user_data_or_fixture)
+{
+  list_t *list = list_new();
+
+  assert_null(list);
+
+  list_destroy(list);
+
+  return MUNIT_OK;
+}
+
+static MunitResult
+test_list_prepend(const MunitParameter params[], void *user_data_or_fixture)
+{
+  list_t *list = list_new();
+
+  int number1 = 1;
+  int number2 = 2;
+
+  list_prepend(&list, (void *)&number1);
+  list_prepend(&list, (void *)&number2);
+
+  assert_int(list_get_size(list), ==, 2);
+  assert_int(*((int *)list->data), ==, number2);
+  assert_int(*((int *)list->next->data), ==, number1);
+
+  list_destroy(list);
+
+  return MUNIT_OK;
+}
+
+static MunitTest tests[] = { { "/test_create_new", test_create_new, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL },
+                             { "/test_list_prepend", test_list_prepend, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL },
+                             { NULL, NULL, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL } };
+
+static const MunitSuite suite = { "/list", tests, NULL, 1, MUNIT_SUITE_OPTION_NONE };
+
+int
+main(int argc, char *argv[])
+{
+  return munit_suite_main(&suite, NULL, argc, argv);
+  return EXIT_SUCCESS;
+}