fix invalid syntax not being called on an invalid assignment

src/dynamic_array/darray.c

@@ -1,77 +1,109 @@
+#include "darray.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include "darray.h"
 
 void darray_init(DArray *arr, size_t element_size) {
-    arr->element_size = element_size;
-    arr->size = 0;
-    arr->capacity = CHUNK_SIZE;
-    arr->data = malloc(CHUNK_SIZE * element_size);
-    if (!arr->data) {
-        fprintf(stderr, "darray_init: allocation failed\n");
-        exit(EXIT_FAILURE);
-    }
+  arr->element_size = element_size;
+  arr->size = 0;
+  arr->capacity = CHUNK_SIZE;
+  arr->data = malloc(CHUNK_SIZE * element_size);
+  arr->resizable = true;
+  if (!arr->data) {
+    fprintf(stderr, "darray_init: allocation failed\n");
+    exit(EXIT_FAILURE);
+  }
 }
 
 void darray_resize(DArray *arr, size_t new_size) {
-    size_t new_capacity = ((new_size + CHUNK_SIZE) / CHUNK_SIZE) * CHUNK_SIZE;
-    if (new_capacity != arr->capacity) {
-        void *new_data = realloc(arr->data, new_capacity * arr->element_size);
-        if (!new_data) {
-            fprintf(stderr, "darray_resize: reallocation failed\n");
-            exit(EXIT_FAILURE);
-        }
-        arr->data = new_data;
-        arr->capacity = new_capacity;
+  if (!arr->resizable) {
+    fprintf(stderr, "darray_resize: unresizable darray\n");
+    exit(EXIT_FAILURE);
+  }
+  size_t new_capacity = ((new_size + CHUNK_SIZE) / CHUNK_SIZE) * CHUNK_SIZE;
+  if (new_capacity != arr->capacity) {
+    void *new_data = realloc(arr->data, new_capacity * arr->element_size);
+    if (!new_data) {
+      fprintf(stderr, "darray_resize: reallocation failed\n");
+      exit(EXIT_FAILURE);
     }
+    arr->data = new_data;
+    arr->capacity = new_capacity;
+  }
 
-    arr->size = new_size;
+  arr->size = new_size;
 }
 
 void darray_push(DArray *arr, void *element) {
-    if (arr->size >= arr->capacity) {
-        darray_resize(arr, arr->size + 1);
-    } else {
-        arr->size++;
-    }
+  if (!arr->resizable) {
+    fprintf(stderr, "darray_resize: unresizable darray\n");
+    exit(EXIT_FAILURE);
+  }
+  if (arr->size >= arr->capacity) {
+    darray_resize(arr, arr->size + 1);
+  } else {
+    arr->size++;
+  }
 
-    void *target = (void *)arr->data + (arr->size - 1) * arr->element_size;
-    memcpy(target, element, arr->element_size);
+  void *target = (char *)arr->data + (arr->size - 1) * arr->element_size;
+  memcpy(target, element, arr->element_size);
 }
 
 void darray_pop(DArray *arr, void (*free_data)(void *)) {
-    if (arr->size == 0)
-        return;
+  if (!arr->resizable) {
+    fprintf(stderr, "darray_resize: unresizable darray\n");
+    exit(EXIT_FAILURE);
+  }
+  if (arr->size == 0)
+    return;
 
-    arr->size--;
+  if (free_data) {
+    void *target = (char *)arr->data + (arr->size-1) * arr->element_size;
+    free_data(target);
+  }
 
-    if (free_data) {
-        void *target = (void *)arr->data + arr->size * arr->element_size;
-        free_data(target);
-    }
-
-    darray_resize(arr, arr->size);
+  darray_resize(arr, arr->size);
 }
 
 void *darray_get(DArray *arr, size_t index) {
-    if (index >= arr->size) {
-        fprintf(stderr, "darray_get: index out of bounds\n");
-        exit(EXIT_FAILURE);
-    }
-    return (void *)arr->data + index * arr->element_size;
+  if (index >= arr->size) {
+    fprintf(stderr, "darray_get: index out of bounds\n");
+    exit(EXIT_FAILURE);
+  }
+  return (char *)arr->data + index * arr->element_size;
+}
+
+DArray darray_slice(DArray *arr, size_t start, size_t end) {
+  if (start > end || end > arr->size) {
+    fprintf(stderr, "darray_slice: invalid slice range\n");
+    exit(EXIT_FAILURE);
+  }
+
+  DArray slice;
+
+  slice.data = (char *)arr->data + start * arr->element_size;
+  slice.size = (end - start);
+  slice.element_size = arr->element_size;
+  slice.capacity = ((slice.size + CHUNK_SIZE) / CHUNK_SIZE) * CHUNK_SIZE;
+  slice.resizable = false;
+
+  return slice;
 }
 
 void darray_free(DArray *arr, void (*free_data)(void *)) {
-    if (free_data) {
-        for (size_t i = 0; i < arr->size; ++i) {
-            void *element = (void *)arr->data + i * arr->element_size;
-            free_data(element);
-        }
+  if (!arr->resizable) {
+    // It's a view/slice — don't free
+    return;
+  }
+  if (free_data) {
+    for (size_t i = 0; i < arr->size; ++i) {
+      void *element = (char *)arr->data + i * arr->element_size;
+      free_data(element);
     }
-    free(arr->data);
-    arr->data = NULL;
-    arr->size = 0;
-    arr->capacity = 0;
-    arr->element_size = 0;
+  }
+  free(arr->data);
+  arr->data = NULL;
+  arr->size = 0;
+  arr->capacity = 0;
+  arr->element_size = 0;
 }