Basic implementation of import.
import works for simple cases. Still work to do on finding the right
script, and setting globals/locals correctly when running an imported
function.
diff --git a/py/builtinimport.c b/py/builtinimport.c
new file mode 100644
index 0000000..f1479ab
--- /dev/null
+++ b/py/builtinimport.c
@@ -0,0 +1,84 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <assert.h>
+
+#include "nlr.h"
+#include "misc.h"
+#include "mpconfig.h"
+#include "lexer.h"
+#include "lexerunix.h"
+#include "parse.h"
+#include "compile.h"
+#include "obj.h"
+#include "runtime0.h"
+#include "runtime.h"
+#include "map.h"
+#include "builtin.h"
+
+mp_obj_t mp_builtin___import__(int n, mp_obj_t *args) {
+ /*
+ printf("import:\n");
+ for (int i = 0; i < n; i++) {
+ printf(" ");
+ mp_obj_print(args[i]);
+ printf("\n");
+ }
+ */
+
+ // find the file to import
+ qstr mod_name = mp_obj_get_qstr(args[0]);
+ mp_lexer_t *lex = mp_import_open_file(mod_name);
+ if (lex == NULL) {
+ // TODO handle lexer error correctly
+ return mp_const_none;
+ }
+
+ // create a new module object
+ mp_obj_t module_obj = mp_obj_new_module(mp_obj_get_qstr(args[0]));
+
+ // save the old context
+ mp_map_t *old_locals = rt_locals_get();
+ mp_map_t *old_globals = rt_globals_get();
+
+ // set the new context
+ rt_locals_set(mp_obj_module_get_globals(module_obj));
+ rt_globals_set(mp_obj_module_get_globals(module_obj));
+
+ // parse the imported script
+ mp_parse_node_t pn = mp_parse(lex, MP_PARSE_FILE_INPUT);
+ mp_lexer_free(lex);
+
+ if (pn == MP_PARSE_NODE_NULL) {
+ // TODO handle parse error correctly
+ rt_locals_set(old_locals);
+ rt_globals_set(old_globals);
+ return mp_const_none;
+ }
+
+ if (!mp_compile(pn, false)) {
+ // TODO handle compile error correctly
+ rt_locals_set(old_locals);
+ rt_globals_set(old_globals);
+ return mp_const_none;
+ }
+
+ // complied successfully, execute it
+ mp_obj_t module_fun = rt_make_function_from_id(1); // TODO we should return from mp_compile the unique_code_id for the module
+ nlr_buf_t nlr;
+ if (nlr_push(&nlr) == 0) {
+ rt_call_function_0(module_fun);
+ nlr_pop();
+ } else {
+ // exception; restore context and re-raise same exception
+ rt_locals_set(old_locals);
+ rt_globals_set(old_globals);
+ nlr_jump(nlr.ret_val);
+ }
+ rt_locals_set(old_locals);
+ rt_globals_set(old_globals);
+
+ return module_obj;
+}