From 0199137fb01e3b329e331c628ff51fd4de17780c Mon Sep 17 00:00:00 2001
From: Windel Bouwman <windel@windel.nl>
Date: Sat, 3 Nov 2018 15:45:50 +0100
Subject: [PATCH] Add sum builtin function.

---
 tests/snippets/builtins.py |  3 +++
 vm/src/builtins.rs         | 25 +++++++++++++++++++++----
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/tests/snippets/builtins.py b/tests/snippets/builtins.py
index d6214455f..655f1bef4 100644
--- a/tests/snippets/builtins.py
+++ b/tests/snippets/builtins.py
@@ -2,3 +2,6 @@
 a = list(map(str, [1, 2, 3]))
 assert a == ['1', '2', '3']
 
+x = sum(map(int, a))
+assert x == 6
+
diff --git a/vm/src/builtins.rs b/vm/src/builtins.rs
index 5c989435c..bd072c8ba 100644
--- a/vm/src/builtins.rs
+++ b/vm/src/builtins.rs
@@ -19,7 +19,7 @@ use super::pyobject::{
 };
 use super::vm::VirtualMachine;
 use num_bigint::ToBigInt;
-use num_traits::{Signed, ToPrimitive};
+use num_traits::{Signed, ToPrimitive, Zero};
 
 fn get_locals(vm: &mut VirtualMachine) -> PyObjectRef {
     let d = vm.new_dict();
@@ -61,7 +61,9 @@ fn builtin_abs(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 }
 
 fn builtin_all(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
-    for item in args.args {
+    arg_check!(vm, args, required = [(iterable, None)]);
+    let items = vm.extract_elements(iterable)?;
+    for item in items {
         let result = objbool::boolval(vm, item)?;
         if !result {
             return Ok(vm.new_bool(false));
@@ -71,7 +73,9 @@ fn builtin_all(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 }
 
 fn builtin_any(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
-    for item in args.args {
+    arg_check!(vm, args, required = [(iterable, None)]);
+    let items = vm.extract_elements(iterable)?;
+    for item in items {
         let result = objbool::boolval(vm, item)?;
         if result {
             return Ok(vm.new_bool(true));
@@ -501,7 +505,19 @@ fn builtin_setattr(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 // builtin_slice
 // builtin_sorted
 // builtin_staticmethod
-// builtin_sum
+
+fn builtin_sum(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(vm, args, required = [(iterable, None)]);
+    let items = vm.extract_elements(iterable)?;
+
+    // Start with zero and add at will:
+    let mut sum = vm.ctx.new_int(Zero::zero());
+    for item in items {
+        sum = vm._add(sum, item)?;
+    }
+    Ok(sum)
+}
+
 // builtin_super
 // builtin_vars
 // builtin_zip
@@ -563,6 +579,7 @@ pub fn make_module(ctx: &PyContext) -> PyObjectRef {
     dict.insert(String::from("set"), ctx.set_type());
     dict.insert(String::from("setattr"), ctx.new_rustfunc(builtin_setattr));
     dict.insert(String::from("str"), ctx.str_type());
+    dict.insert(String::from("sum"), ctx.new_rustfunc(builtin_sum));
     dict.insert(String::from("tuple"), ctx.tuple_type());
     dict.insert(String::from("type"), ctx.type_type());