add structs copy demo

Author: geeksilva97

conditionals.c

@@ -561,6 +561,29 @@ lval *builtin_eval(lenv *e, lval *a) {
   return lval_eval(e, x);
 }
 
+lval *builtin_if(lenv *e, lval *a) {
+  LASSERT_NUM("if", a, 3);
+  LASSERT_TYPE("if", a, 0, LVAL_BOOL);
+  LASSERT_TYPE("if", a, 1, LVAL_QEXPR);
+  LASSERT_TYPE("if", a, 2, LVAL_QEXPR);
+
+  int cond = a->cell[0]->bool_val;
+
+  lval *x;
+
+  if (cond) {
+    x = lval_take(a, 1);
+  } else {
+    x = lval_take(a, 2);
+  }
+
+  lval_del(a);
+
+  x->type = LVAL_SEXPR;
+
+  return lval_eval(e, x);
+}
+
 lval *builtin_join(lenv *e, lval *a) {
 
   for (int i = 0; i < a->count; i++) {
@@ -693,6 +716,10 @@ void lenv_add_builtins(lenv *e) {
   lenv_add_builtin(e, "!=", builtin_uneq);
   lenv_add_builtin(e, ">=", builtin_ge);
   lenv_add_builtin(e, "<=", builtin_le);
+
+  /* Conditionals */
+
+  lenv_add_builtin(e, "if", builtin_if);
 }
 
 /* Evaluation */

copy_structs.c

@@ -0,0 +1,218 @@
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct {
+  char *title;
+  char **messages;
+  size_t num_messages;
+} channel_t;
+
+void remove_message(channel_t *channel, size_t index) {
+  if (index >= channel->num_messages) {
+    perror("Error while removing message: Invalid index");
+    return exit(EXIT_FAILURE);
+  }
+
+  free(channel->messages[index]);
+
+  for (size_t i = index; i < channel->num_messages - 1; i++) {
+    channel->messages[i] = channel->messages[i + 1];
+  }
+
+  channel->num_messages--;
+
+  if (channel->num_messages == 0) {
+    free(channel->messages);
+    channel->messages = NULL;
+  } else {
+    channel->messages =
+        realloc(channel->messages, sizeof(char *) * channel->num_messages);
+  }
+}
+
+void update_message(channel_t *channel, size_t index, char *new_message) {
+  if (index >= channel->num_messages) {
+    perror("Error while removing message: Invalid index");
+    return exit(EXIT_FAILURE);
+  }
+
+  free(channel->messages[index]);
+
+  channel->messages[index] = malloc(strlen(new_message) + 1);
+
+  strcpy(channel->messages[index], new_message);
+}
+
+void add_message(channel_t *channel, char *message) {
+  printf("Adding message to the channel %s\n"
+         "There are %lu messages at this moment.\n",
+         channel->title, channel->num_messages);
+
+  channel->num_messages++;
+  channel->messages =
+      realloc(channel->messages, sizeof(char *) * channel->num_messages);
+  channel->messages[channel->num_messages - 1] = malloc(strlen(message) + 1);
+
+  strcpy(channel->messages[channel->num_messages - 1], message);
+}
+
+channel_t *create_channel(char *channel_title) {
+  channel_t *channel = malloc(sizeof(channel_t));
+  /* Até é possivel setart a string sem o malloc, mas mudar depois falha
+      Tomei um bus error */
+  channel->title = malloc(strlen(channel_title) + 1);
+  channel->title = strcpy(channel->title, channel_title);
+
+  return channel;
+}
+
+void print_size_struct(channel_t *channel) {
+  size_t s = sizeof(*(channel));
+
+  printf("Struct size: %lu\n", s);
+
+  printf("Size of title: %lu\n"
+         "Size of num_messages: %lu\n"
+         "Size of messages: %lu\n",
+         sizeof(channel->title), sizeof(channel->messages),
+         sizeof(channel->num_messages));
+}
+
+void print_channel(channel_t *channel) {
+  printf("===== Printing channel =======\n"
+         "[Title]: %s\n"
+         "[N messages]: %lu\n",
+         channel->title, channel->num_messages);
+
+  for (int i = 0; i < channel->num_messages; i++) {
+    printf("Message %i\n%s\n\n", i + 1, channel->messages[i]);
+  }
+}
+
+channel_t *clone2(channel_t *channel) {
+  size_t size = sizeof(*channel);
+
+  channel_t *new_channel = malloc(size);
+
+  memcpy(new_channel, channel, size);
+
+  return new_channel;
+}
+
+size_t my_str_len(char *str) {
+  size_t n = 0;
+
+  while (*str) {
+    printf("Contando char '%c'\n", *str);
+    str++;
+    n++;
+  }
+
+  return n;
+}
+
+channel_t *clone(channel_t *channel) {
+  printf("Cloning chanel '%s'\n\n", channel->title);
+
+  channel_t *new_channel = malloc(sizeof(channel_t));
+
+  new_channel->num_messages = channel->num_messages;
+  new_channel->title = malloc(strlen(channel->title) + 1);
+  new_channel->messages = malloc(sizeof(char *) * channel->num_messages);
+
+  stpcpy(new_channel->title, channel->title);
+
+  int mem = 0;
+
+  for (int i = 0; i < channel->num_messages; i++) {
+    char *message = channel->messages[i];
+
+    mem += strlen(message) + 1;
+  }
+
+  char **messages = malloc(sizeof(char *) * mem);
+
+  for (int i = 0; i < channel->num_messages; i++) {
+    char *message = channel->messages[i];
+
+    strcpy(messages[i], message);
+  }
+
+  memcpy(new_channel->messages, messages, mem);
+
+  /* for (int i = 0; i < channel->num_messages; i++) { */
+  /*   char *message = channel->messages[i]; */
+  /*   new_channel->messages[i] = malloc(strlen(message) + 1); */
+  /*   strcpy(new_channel->messages[i], message); */
+  /* } */
+
+  return new_channel;
+}
+
+int compare(channel_t *channel_a, channel_t *channel_b) {
+  printf("Comparing titles '%s' to '%s'\n\n", channel_a->title,
+         channel_b->title);
+
+  printf("Comparing total of messages '%lu' to '%lu'\n\n",
+         channel_a->num_messages, channel_b->num_messages);
+  if (channel_a->num_messages == channel_b->num_messages &&
+      strcmp(channel_a->title, channel_b->title) == 0) {
+
+    return 1;
+  }
+
+  return 0;
+}
+
+void free_channel(channel_t *channel) {
+  free(channel->title);
+  free(channel->messages);
+  free(channel);
+}
+
+channel_t *copy_channel_with_memcpy(char *channel) {
+  channel_t *new_channel = create_channel("Gotta copy this channel");
+
+  return new_channel;
+}
+
+int main(void) {
+  channel_t *channel = create_channel("This is my channel");
+
+  add_message(channel, "A single message");
+
+  print_channel(channel);
+
+  remove_message(channel, 0);
+
+  channel->title[0] = 'K';
+
+  /* channel_t *cloned_channel = clone2(channel); */
+  channel_t *cloned_channel = clone(channel);
+
+  printf("Original title address: %u\n", *channel->title);
+  printf("Cloned title address: %u\n", *cloned_channel->title);
+
+  char *new_title = "Cloned channel";
+
+  cloned_channel->title = realloc(cloned_channel->title, strlen(new_title) + 1);
+  strcpy(cloned_channel->title, new_title);
+
+  print_channel(channel);
+
+  print_channel(cloned_channel);
+
+  printf("Are channels equal? %s\n\n",
+         compare(channel, cloned_channel) ? "True" : "False");
+
+  free_channel(channel);
+  free_channel(cloned_channel);
+
+  size_t string_size = my_str_len("Edy\n");
+
+  printf("A string tem tamanho %lu\n", string_size);
+
+  return 0;
+}