py: Add framework for built-in "type()" function.

py/builtin.c

@@ -410,3 +410,16 @@ mp_obj_t mp_builtin_sum(int n_args, const mp_obj_t *args) {
     }
     return value;
 }
+
+static mp_obj_t mp_builtin_type(mp_obj_t o_in) {
+    // TODO implement the 3 argument version of type()
+    if (MP_OBJ_IS_SMALL_INT(o_in)) {
+        // TODO implement int-type
+        return mp_const_none;
+    } else {
+        mp_obj_base_t *o = o_in;
+        return (mp_obj_t)o->type;
+    }
+}
+
+MP_DEFINE_CONST_FUN_OBJ_1(mp_builtin_type_obj, mp_builtin_type);

py/builtin.h

@@ -31,3 +31,4 @@ mp_obj_t mp_builtin_print(int n_args, const mp_obj_t *args);
 mp_obj_t mp_builtin_range(int n_args, const mp_obj_t *args);
 MP_DECLARE_CONST_FUN_OBJ(mp_builtin_set_obj);
 mp_obj_t mp_builtin_sum(int n_args, const mp_obj_t *args);
+MP_DECLARE_CONST_FUN_OBJ(mp_builtin_type_obj);

py/objtype.c

@@ -7,12 +7,12 @@
 #include "obj.h"
 
 void type_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in) {
-    print(env, "type?");
+    print(env, "<a type>");
 }
 
 const mp_obj_type_t mp_const_type = {
     { &mp_const_type },
-    "type?",
+    "<a type>",
     type_print, // print
     NULL, // call_n
     NULL, // unary_op

py/runtime.c

@@ -147,6 +147,7 @@ void rt_init(void) {
     mp_qstr_map_lookup(&map_builtins, qstr_from_str_static("range"), true)->value = rt_make_function_var(1, mp_builtin_range);
     mp_qstr_map_lookup(&map_builtins, qstr_from_str_static("set"), true)->value = (mp_obj_t)&mp_builtin_set_obj;
     mp_qstr_map_lookup(&map_builtins, qstr_from_str_static("sum"), true)->value = rt_make_function_var(1, mp_builtin_sum);
+    mp_qstr_map_lookup(&map_builtins, qstr_from_str_static("type"), true)->value = (mp_obj_t)&mp_builtin_type_obj;
 
 
     next_unique_code_id = 2; // 1 is reserved for the __main__ module scope