From 035a0a2b6e5e3e6908927d3627887fbd581b7469 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Mon, 12 Oct 2015 21:49:03 +0100
Subject: [PATCH] py: Add support for _ in REPL to hold last computed value.

Only available when MICROPY_CAN_OVERRIDE_BUILTINS is enabled.
---
 py/modbuiltins.c | 4 ++++
 py/qstrdefs.h    | 1 +
 2 files changed, 5 insertions(+)

diff --git a/py/modbuiltins.c b/py/modbuiltins.c
index 1f33ab75ec..45fb3ffd9b 100644
--- a/py/modbuiltins.c
+++ b/py/modbuiltins.c
@@ -416,6 +416,10 @@ STATIC mp_obj_t mp_builtin___repl_print__(mp_obj_t o) {
         mp_obj_print_helper(&mp_plat_print, o, PRINT_REPR);
         mp_print_str(&mp_plat_print, "\n");
         #endif
+        #if MICROPY_CAN_OVERRIDE_BUILTINS
+        mp_obj_t dest[2] = {MP_OBJ_SENTINEL, o};
+        mp_type_module.attr((mp_obj_t)&mp_module_builtins, MP_QSTR__, dest);
+        #endif
     }
     return mp_const_none;
 }
diff --git a/py/qstrdefs.h b/py/qstrdefs.h
index dcde1b5c16..161d231127 100644
--- a/py/qstrdefs.h
+++ b/py/qstrdefs.h
@@ -35,6 +35,7 @@ QCFG(BYTES_IN_HASH, MICROPY_QSTR_BYTES_IN_HASH)
 
 Q()
 Q(*)
+Q(_)
 Q(__build_class__)
 Q(__class__)
 Q(__doc__)