Implement default function arguments (for Python functions).

TODO: Decide if we really need separate bytecode for creating functions
with default arguments - we would need same for closures, then there're
keywords arguments too. Having all combinations is a small exponential
explosion, likely we need just 2 cases - simplest (no defaults, no kw),
and full - defaults & kw.

1 files changed, 9 insertions, 3 deletions

diff --git a/py/emitbc.c b/py/emitbc.c
index d74b06525..10a93d5b6 100644
--- a/py/emitbc.c
+++ b/py/emitbc.c
@@ -664,9 +664,15 @@ static void emit_bc_unpack_ex(emit_t *emit, int n_left, int n_right) {
 }
 
 static void emit_bc_make_function(emit_t *emit, scope_t *scope, int n_dict_params, int n_default_params) {
-    assert(n_default_params == 0 && n_dict_params == 0);
-    emit_pre(emit, 1);
-    emit_write_byte_code_byte_uint(emit, MP_BC_MAKE_FUNCTION, scope->unique_code_id);
+    assert(n_dict_params == 0);
+    if (n_default_params != 0) {
+        emit_bc_build_tuple(emit, n_default_params);
+        emit_pre(emit, 0);
+        emit_write_byte_code_byte_uint(emit, MP_BC_MAKE_FUNCTION_DEFARGS, scope->unique_code_id);
+    } else {
+        emit_pre(emit, 1);
+        emit_write_byte_code_byte_uint(emit, MP_BC_MAKE_FUNCTION, scope->unique_code_id);
+    }
 }
 
 static void emit_bc_make_closure(emit_t *emit, scope_t *scope, int n_dict_params, int n_default_params) {