Cleanup slice_new and added more slice tests

skinnyBat · skinnyBat · commit a49895ef63a8 · 2019-03-31T09:58:02.000+13:00
diff --git a/tests/snippets/builtin_slice.py b/tests/snippets/builtin_slice.py
@@ -11,6 +11,7 @@
 b = [1, 2]
 
 assert b[:] == [1, 2]
+assert b[slice(None)] == [1, 2]
 assert b[:2**100] == [1, 2]
 assert b[-2**100:] == [1, 2]
 assert b[2**100:] == []
@@ -77,3 +78,15 @@ def __setitem__(self, key, value):
 ss = SubScript()
 _ = ss[:]
 ss[:1] = 1
+
+
+class CustomIndex:
+    def __init__(self, x):
+        self.x = x
+
+    def __index__(self):
+        return self.x
+
+
+assert c[CustomIndex(1):CustomIndex(3)] == [1, 2]
+assert d[CustomIndex(1):CustomIndex(3)] == "23"
diff --git a/vm/src/function.rs b/vm/src/function.rs
@@ -1,4 +1,5 @@
 use std::collections::HashMap;
+use std::mem;
 use std::ops::RangeInclusive;
 
 use crate::obj::objtype::{isinstance, PyClassRef};
@@ -46,6 +47,12 @@ impl From<(&Args, &KwArgs)> for PyFuncArgs {
     }
 }
 
+impl FromArgs for PyFuncArgs {
+    fn from_args(_vm: &VirtualMachine, args: &mut PyFuncArgs) -> Result<Self, ArgumentError> {
+        Ok(mem::replace(args, Default::default()))
+    }
+}
+
 impl PyFuncArgs {
     pub fn new(mut args: Vec<PyObjectRef>, kwarg_names: Vec<String>) -> PyFuncArgs {
         let mut kwargs = vec![];
diff --git a/vm/src/obj/objslice.rs b/vm/src/obj/objslice.rs
@@ -24,25 +24,22 @@ impl PyValue for PySlice {
 
 pub type PySliceRef = PyRef<PySlice>;
 
-fn slice_new(vm: &VirtualMachine, args: PyFuncArgs) -> PyResult {
-    let (cls, slice): (PyClassRef, PySlice) = match args.args.len() {
-        0 | 1 => {
+fn slice_new(cls: PyClassRef, args: PyFuncArgs, vm: &VirtualMachine) -> PyResult<PySliceRef> {
+    let slice: PySlice = match args.args.len() {
+        0 => {
             return Err(vm.new_type_error("slice() must have at least one arguments.".to_owned()));
         }
-        2 => {
-            let (cls, stop) = args.bind(vm)?;
-            (
-                cls,
-                PySlice {
-                    start: None,
-                    stop: Some(stop),
-                    step: None,
-                },
-            )
+        1 => {
+            let stop = args.bind(vm)?;
+            PySlice {
+                start: None,
+                stop: Some(stop),
+                step: None,
+            }
         }
         _ => args.bind(vm)?,
     };
-    slice.into_ref_with_type(vm, cls).map(|x| x.into_object())
+    slice.into_ref_with_type(vm, cls)
 }
 
 fn get_property_value(vm: &VirtualMachine, value: &Option<PyObjectRef>) -> PyObjectRef {
