py: Add native json printing using existing print framework.

Also add start of ujson module with dumps implemented.  Enabled in unix
and stmhal ports.  Test passes on both.

1 files changed, 4 insertions, 1 deletions

diff --git a/py/objlist.c b/py/objlist.c
index 59390f371f..789a1600d3 100644
--- a/py/objlist.c
+++ b/py/objlist.c
@@ -49,12 +49,15 @@ STATIC mp_obj_t list_pop(mp_uint_t n_args, const mp_obj_t *args);
 
 STATIC void list_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t o_in, mp_print_kind_t kind) {
     mp_obj_list_t *o = o_in;
+    if (!(MICROPY_PY_UJSON && kind == PRINT_JSON)) {
+        kind = PRINT_REPR;
+    }
     print(env, "[");
     for (mp_uint_t i = 0; i < o->len; i++) {
         if (i > 0) {
             print(env, ", ");
         }
-        mp_obj_print_helper(print, env, o->items[i], PRINT_REPR);
+        mp_obj_print_helper(print, env, o->items[i], kind);
     }
     print(env, "]");
 }