wip: working on extern in VM

- Feat: add writer externs writing fns
- Feat: add VM reader functions

src/vm/reader/utility.c

@@ -0,0 +1,32 @@
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <vm/internals/reader.h>
+
+// Read characters with red bytes check
+bool vm_rd_char(FILE *fd, size_t count, char *o)
+{
+  if (!fd || !o)
+    return false;
+
+  return fread(o, sizeof(char), count, fd) == (sizeof(char) * count);
+}
+
+// Read 16-byte uints with red bytes check
+bool vm_rd_u16(FILE *fd, size_t count, uint16_t *o)
+{
+  if (!fd || !o)
+    return false;
+
+  return fread(o, sizeof(uint16_t), count, fd) == (sizeof(uint16_t) * count);
+}
+
+// Read machine word-size uints with red bytes check
+bool vm_rd_word(FILE *fd, size_t count, size_t *o)
+{
+  if (!fd || !o)
+    return false;
+
+  return fread(o, sizeof(size_t), count, fd) == (sizeof(size_t) * count);
+}