Upversioned the C source tree to '0.0.7-SNAPSHOT', but proposing to start experimental

work towards 0.1.0 in separate source trees.

src/c/ops/meta.c

@@ -0,0 +1,45 @@
+/*
+ * 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 "memory/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.stream.meta;
+            break;
+    }
+
+    return make_cons( make_cons( c_string_to_lisp_keyword( L"type" ),
+                                 c_type( frame->arg[0] ) ), result );
+
+//  return result;
+}