Add size_hint() to PyIterator

coolreader18 · youknowone · commit 490c638b4f16 · 2020-06-21T19:33:12.000+09:00
diff --git a/vm/src/pyobject.rs b/vm/src/pyobject.rs
@@ -980,9 +980,12 @@ impl<T> PyIterable<T> {
             },
         )?;
 
+        let lenhint = objiter::length_hint(vm, iter_obj.clone())?;
+
         Ok(PyIterator {
             vm,
             obj: iter_obj,
+            lenhint,
             _item: std::marker::PhantomData,
         })
     }
@@ -991,6 +994,7 @@ impl<T> PyIterable<T> {
 pub struct PyIterator<'a, T> {
     vm: &'a VirtualMachine,
     obj: PyObjectRef,
+    lenhint: Option<usize>,
     _item: std::marker::PhantomData<T>,
 }
 
@@ -1012,6 +1016,10 @@ where
             }
         }
     }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (self.lenhint.unwrap_or(0), self.lenhint)
+    }
 }
 
 impl<T> TryFromObject for PyIterable<T>

Original file line number	Diff line number	Diff line change
`@@ -980,9 +980,12 @@ impl<T> PyIterable<T> {`
`980`	`980`	`},`
`981`	`981`	`)?;`
`982`	`982`
	`983`	`+ let lenhint = objiter::length_hint(vm, iter_obj.clone())?;`
	`984`	`+`
`983`	`985`	`Ok(PyIterator {`
`984`	`986`	`vm,`
`985`	`987`	`obj: iter_obj,`
	`988`	`+ lenhint,`
`986`	`989`	`_item: std::marker::PhantomData,`
`987`	`990`	`})`
`988`	`991`	`}`
`@@ -991,6 +994,7 @@ impl<T> PyIterable<T> {`
`991`	`994`	`pub struct PyIterator<'a, T> {`
`992`	`995`	`vm: &'a VirtualMachine,`
`993`	`996`	`obj: PyObjectRef,`
	`997`	`+ lenhint: Option<usize>,`
`994`	`998`	`_item: std::marker::PhantomData<T>,`
`995`	`999`	`}`
`996`	`1000`
`@@ -1012,6 +1016,10 @@ where`
`1012`	`1016`	`}`
`1013`	`1017`	`}`
`1014`	`1018`	`}`
	`1019`	`+`
	`1020`	`+ fn size_hint(&self) -> (usize, Option<usize>) {`
	`1021`	`+ (self.lenhint.unwrap_or(0), self.lenhint)`
	`1022`	`+ }`
`1015`	`1023`	`}`
`1016`	`1024`
`1017`	`1025`	`impl<T> TryFromObject for PyIterable<T>`