py: make closures work.

1 files changed, 21 insertions, 3 deletions

diff --git a/py/objclosure.c b/py/objclosure.c
index e699c5daa..e3354d42d 100644
--- a/py/objclosure.c
+++ b/py/objclosure.c
@@ -1,5 +1,6 @@
 #include <stdlib.h>
 #include <stdint.h>
+#include <string.h>
 #include <assert.h>
 
 #include "nlr.h"
@@ -11,14 +12,31 @@
 typedef struct _mp_obj_closure_t {
     mp_obj_base_t base;
     mp_obj_t fun;
-    mp_obj_t vars;
+    uint n_closed;
+    mp_obj_t *closed;
 } mp_obj_closure_t;
 
+// args are in reverse order in the array
+mp_obj_t closure_call_n(mp_obj_t self_in, int n_args, const mp_obj_t *args) {
+    mp_obj_closure_t *self = self_in;
+
+    // concatenate args and closed-over-vars, in reverse order
+    // TODO perhaps cache this array so we don't need to create it each time we are called
+    mp_obj_t *args2 = m_new(mp_obj_t, self->n_closed + n_args);
+    memcpy(args2, args, n_args * sizeof(mp_obj_t));
+    for (int i = 0; i < self->n_closed; i++) {
+        args2[n_args + i] = self->closed[self->n_closed - 1 - i];
+    }
+
+    // call the function with the new vars array
+    return rt_call_function_n(self->fun, n_args + self->n_closed, args2);
+}
+
 const mp_obj_type_t closure_type = {
     { &mp_const_type },
     "closure",
     NULL, // print
-    NULL, // call_n
+    closure_call_n, // call_n
     NULL, // unary_op
     NULL, // binary_op
     NULL, // getiter
@@ -30,6 +48,6 @@ mp_obj_t mp_obj_new_closure(mp_obj_t fun, mp_obj_t closure_tuple) {
     mp_obj_closure_t *o = m_new_obj(mp_obj_closure_t);
     o->base.type = &closure_type;
     o->fun = fun;
-    o->vars = closure_tuple;
+    mp_obj_tuple_get(closure_tuple, &o->n_closed, &o->closed);
     return o;
 }