Merge pull request RustPython#3734 from gnsxun/map-mod

Add map.reduce()

Author: youknowone

Lib/test/test_builtin.py

@@ -925,8 +925,6 @@ def badfunc(x):
             raise RuntimeError
         self.assertRaises(RuntimeError, list, map(badfunc, range(5)))
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_map_pickle(self):
         for proto in range(pickle.HIGHEST_PROTOCOL + 1):
             m1 = map(map_char, "Is this the real life?")

Lib/test/test_pickle.py

@@ -100,8 +100,6 @@ def test_buffers_error(self): # TODO: RUSTPYTHON, remove when this passes
     def test_c_methods(self): # TODO: RUSTPYTHON, remove when this passes
         super().test_c_methods() # TODO: RUSTPYTHON, remove when this passes
 
-    # TODO: RUSTPYTHON, TypeError: cannot pickle 'map' object
-    @unittest.expectedFailure
     def test_compat_pickle(self): # TODO: RUSTPYTHON, remove when this passes
         super().test_compat_pickle() # TODO: RUSTPYTHON, remove when this passes
 
@@ -211,8 +209,6 @@ def test_buffers_error(self): # TODO: RUSTPYTHON, remove when this passes
     def test_c_methods(self): # TODO: RUSTPYTHON, remove when this passes
         super().test_c_methods() # TODO: RUSTPYTHON, remove when this passes
 
-    # TODO: RUSTPYTHON, TypeError: cannot pickle 'map' object
-    @unittest.expectedFailure
     def test_compat_pickle(self): # TODO: RUSTPYTHON, remove when this passes
         super().test_compat_pickle() # TODO: RUSTPYTHON, remove when this passes
 

Lib/test/test_pickletools.py

@@ -22,8 +22,6 @@ def test_buffers_error(self): # TODO: RUSTPYTHON, remove when this passes
     def test_c_methods(self): # TODO: RUSTPYTHON, remove when this passes
         super().test_c_methods()
 
-    # TODO: RUSTPYTHON, TypeError: cannot pickle 'map' object
-    @unittest.expectedFailure
     def test_compat_pickle(self): # TODO: RUSTPYTHON, remove when this passes
         super().test_compat_pickle()
 

vm/src/builtins/map.rs

@@ -1,5 +1,6 @@
 use super::PyTypeRef;
 use crate::{
+    builtins::PyTupleRef,
     class::PyClassImpl,
     function::PosArgs,
     protocol::{PyIter, PyIterReturn},
@@ -45,6 +46,13 @@ impl PyMap {
             Ok(max)
         })
     }
+
+    #[pymethod(magic)]
+    fn reduce(&self, vm: &VirtualMachine) -> (PyTypeRef, PyTupleRef) {
+        let mut vec = vec![self.mapper.clone()];
+        vec.extend(self.iterators.iter().map(|o| o.clone().into()));
+        (vm.ctx.types.map_type.clone(), vm.new_tuple(vec))
+    }
 }
 
 impl IterNextIterable for PyMap {}