Setting up medatata works...

And the `inspect` function correctly shows it. However, the `metadata` function segfaults.

src/ops/meta.c

@@ -0,0 +1,47 @@
+/*
+ * meta.c
+ *
+ * Get metadata from a cell which has it.
+ *
+ * (c) 2019 Simon Brooke <simon@journeyman.cc>
+ * Licensed under GPL version 2.0, or, at your option, any later version.
+ */
+
+#include "conspage.h"
+#include "debug.h"
+
+/**
+ * Function: get metadata describing my first argument.
+ *
+ * * (metadata any)
+ *
+ * @return a pointer to the metadata of my first argument, or nil if none.
+ */
+struct cons_pointer lisp_metadata( struct stack_frame *frame, struct cons_pointer frame_pointer,
+                                  struct cons_pointer env ) {
+  debug_print(L"lisp_metadata: entered\n", DEBUG_EVAL);
+  debug_dump_object(frame->arg[0], DEBUG_EVAL);
+  struct cons_pointer result = NIL;
+  struct cons_space_object cell = pointer2cell(frame->arg[0]);
+
+  switch( cell.tag.value) {
+    case FUNCTIONTV:
+    result = cell.payload.function.meta;
+    break;
+    case SPECIALTV:
+    result = cell.payload.special.meta;
+    break;
+    case READTV:
+    case WRITETV:
+    result = cell.payload.special.meta;
+    break;
+  }
+
+  return make_cons(
+    make_cons(
+      c_string_to_lisp_keyword( L"type"),
+      c_type(frame->arg[0])),
+    result);
+
+//  return result;
+}