Make vm.extract_elements generic

vm/src/frame.rs

@@ -1043,7 +1043,7 @@ impl Frame {
 
     fn execute_unpack_ex(&self, vm: &VirtualMachine, before: usize, after: usize) -> FrameResult {
         let value = self.pop_value();
-        let elements = vm.extract_elements(&value)?;
+        let elements = vm.extract_elements::<PyObjectRef>(&value)?;
         let min_expected = before + after;
         if elements.len() < min_expected {
             Err(vm.new_value_error(format!(

vm/src/obj/objiter.rs

@@ -7,7 +7,7 @@ use std::cell::Cell;
 use super::objtuple::PyTuple;
 use super::objtype::{self, PyClassRef};
 use crate::pyobject::{
-    PyClassImpl, PyContext, PyObjectRef, PyRef, PyResult, PyValue, TypeProtocol,
+    PyClassImpl, PyContext, PyObjectRef, PyRef, PyResult, PyValue, TryFromObject, TypeProtocol,
 };
 use crate::vm::VirtualMachine;
 
@@ -60,14 +60,10 @@ pub fn get_next_object(
 }
 
 /* Retrieve all elements from an iterator */
-pub fn get_all(vm: &VirtualMachine, iter_obj: &PyObjectRef) -> PyResult<Vec<PyObjectRef>> {
+pub fn get_all<T: TryFromObject>(vm: &VirtualMachine, iter_obj: &PyObjectRef) -> PyResult<Vec<T>> {
     let mut elements = vec![];
-    loop {
-        let element = get_next_object(vm, iter_obj)?;
-        match element {
-            Some(v) => elements.push(v),
-            None => break,
-        }
+    while let Some(element) = get_next_object(vm, iter_obj)? {
+        elements.push(T::try_from_object(vm, element)?);
     }
     Ok(elements)
 }

vm/src/pyobject.rs

@@ -941,6 +941,7 @@ where
 }
 
 impl TryFromObject for PyObjectRef {
+    #[inline]
     fn try_from_object(_vm: &VirtualMachine, obj: PyObjectRef) -> PyResult<Self> {
         Ok(obj)
     }

vm/src/vm.rs

@@ -808,17 +808,22 @@ impl VirtualMachine {
         Ok(())
     }
 
-    pub fn extract_elements(&self, value: &PyObjectRef) -> PyResult<Vec<PyObjectRef>> {
+    pub fn extract_elements<T: TryFromObject>(&self, value: &PyObjectRef) -> PyResult<Vec<T>> {
         // Extract elements from item, if possible:
-        let elements = if objtype::isinstance(value, &self.ctx.tuple_type()) {
-            objsequence::get_elements_tuple(value).to_vec()
+        if objtype::isinstance(value, &self.ctx.tuple_type()) {
+            objsequence::get_elements_tuple(value)
+                .iter()
+                .map(|obj| T::try_from_object(self, obj.clone()))
+                .collect()
         } else if objtype::isinstance(value, &self.ctx.list_type()) {
-            objsequence::get_elements_list(value).to_vec()
+            objsequence::get_elements_list(value)
+                .iter()
+                .map(|obj| T::try_from_object(self, obj.clone()))
+                .collect()
         } else {
             let iter = objiter::get_iter(self, value)?;
-            objiter::get_all(self, &iter)?
-        };
-        Ok(elements)
+            objiter::get_all(self, &iter)
+        }
     }
 
     // get_attribute should be used for full attribute access (usually from user code).