Fix (in) operator

Resolves   #725.

__coconut__/__init__.pyi

@@ -874,7 +874,8 @@ def _coconut_bool_or(a: _t.Literal[False], b: _T) -> _T: ...
 def _coconut_bool_or(a: _T, b: _U) -> _t.Union[_T, _U]: ...
 
 
-def _coconut_not_in(a: _T, b: _t.Sequence[_T]) -> bool: ...
+def _coconut_in(a: _T, b: _t.Sequence[_T]) -> bool: ...
+_coconut_not_in = _coconut_in
 
 
 @_t.overload

coconut/__coconut__.pyi

@@ -1,2 +1,2 @@
 from __coconut__ import *
-from __coconut__ import _coconut_tail_call, _coconut_tco, _coconut_call_set_names, _coconut_handle_cls_kwargs, _coconut_handle_cls_stargs, _namedtuple_of, _coconut, _coconut_super, _coconut_Expected, _coconut_MatchError, _coconut_iter_getitem, _coconut_base_compose, _coconut_forward_compose, _coconut_back_compose, _coconut_forward_star_compose, _coconut_back_star_compose, _coconut_forward_dubstar_compose, _coconut_back_dubstar_compose, _coconut_pipe, _coconut_star_pipe, _coconut_dubstar_pipe, _coconut_back_pipe, _coconut_back_star_pipe, _coconut_back_dubstar_pipe, _coconut_none_pipe, _coconut_none_star_pipe, _coconut_none_dubstar_pipe, _coconut_bool_and, _coconut_bool_or, _coconut_none_coalesce, _coconut_minus, _coconut_map, _coconut_partial, _coconut_get_function_match_error, _coconut_base_pattern_func, _coconut_addpattern, _coconut_sentinel, _coconut_assert, _coconut_raise, _coconut_mark_as_match, _coconut_reiterable, _coconut_self_match_types, _coconut_dict_merge, _coconut_exec, _coconut_comma_op, _coconut_multi_dim_arr, _coconut_mk_anon_namedtuple, _coconut_matmul, _coconut_py_str, _coconut_flatten, _coconut_multiset, _coconut_back_none_pipe, _coconut_back_none_star_pipe, _coconut_back_none_dubstar_pipe, _coconut_forward_none_compose, _coconut_back_none_compose, _coconut_forward_none_star_compose, _coconut_back_none_star_compose, _coconut_forward_none_dubstar_compose, _coconut_back_none_dubstar_compose, _coconut_call_or_coefficient, _coconut_not_in
+from __coconut__ import _coconut_tail_call, _coconut_tco, _coconut_call_set_names, _coconut_handle_cls_kwargs, _coconut_handle_cls_stargs, _namedtuple_of, _coconut, _coconut_super, _coconut_Expected, _coconut_MatchError, _coconut_iter_getitem, _coconut_base_compose, _coconut_forward_compose, _coconut_back_compose, _coconut_forward_star_compose, _coconut_back_star_compose, _coconut_forward_dubstar_compose, _coconut_back_dubstar_compose, _coconut_pipe, _coconut_star_pipe, _coconut_dubstar_pipe, _coconut_back_pipe, _coconut_back_star_pipe, _coconut_back_dubstar_pipe, _coconut_none_pipe, _coconut_none_star_pipe, _coconut_none_dubstar_pipe, _coconut_bool_and, _coconut_bool_or, _coconut_none_coalesce, _coconut_minus, _coconut_map, _coconut_partial, _coconut_get_function_match_error, _coconut_base_pattern_func, _coconut_addpattern, _coconut_sentinel, _coconut_assert, _coconut_raise, _coconut_mark_as_match, _coconut_reiterable, _coconut_self_match_types, _coconut_dict_merge, _coconut_exec, _coconut_comma_op, _coconut_multi_dim_arr, _coconut_mk_anon_namedtuple, _coconut_matmul, _coconut_py_str, _coconut_flatten, _coconut_multiset, _coconut_back_none_pipe, _coconut_back_none_star_pipe, _coconut_back_none_dubstar_pipe, _coconut_forward_none_compose, _coconut_back_none_compose, _coconut_forward_none_star_compose, _coconut_back_none_star_compose, _coconut_forward_none_dubstar_compose, _coconut_back_none_dubstar_compose, _coconut_call_or_coefficient, _coconut_in, _coconut_not_in

coconut/compiler/grammar.py

@@ -1033,7 +1033,7 @@ class Grammar(object):
         # must come after is not / not in
         | fixto(keyword("not"), "_coconut.operator.not_")
         | fixto(keyword("is"), "_coconut.operator.is_")
-        | fixto(keyword("in"), "_coconut.operator.contains")
+        | fixto(keyword("in"), "_coconut_in")
     )
     partialable_op = base_op_item | infix_op
     partial_op_item_tokens = (

coconut/compiler/header.py

@@ -541,7 +541,7 @@ async def __anext__(self):
     #  (extra_format_dict is to keep indentation levels matching)
     extra_format_dict = dict(
         # when anything is added to this list it must also be added to *both* __coconut__ stub files
-        underscore_imports="{tco_comma}{call_set_names_comma}{handle_cls_args_comma}_namedtuple_of, _coconut, _coconut_super, _coconut_Expected, _coconut_MatchError, _coconut_iter_getitem, _coconut_base_compose, _coconut_forward_compose, _coconut_back_compose, _coconut_forward_star_compose, _coconut_back_star_compose, _coconut_forward_dubstar_compose, _coconut_back_dubstar_compose, _coconut_pipe, _coconut_star_pipe, _coconut_dubstar_pipe, _coconut_back_pipe, _coconut_back_star_pipe, _coconut_back_dubstar_pipe, _coconut_none_pipe, _coconut_none_star_pipe, _coconut_none_dubstar_pipe, _coconut_bool_and, _coconut_bool_or, _coconut_none_coalesce, _coconut_minus, _coconut_map, _coconut_partial, _coconut_get_function_match_error, _coconut_base_pattern_func, _coconut_addpattern, _coconut_sentinel, _coconut_assert, _coconut_raise, _coconut_mark_as_match, _coconut_reiterable, _coconut_self_match_types, _coconut_dict_merge, _coconut_exec, _coconut_comma_op, _coconut_multi_dim_arr, _coconut_mk_anon_namedtuple, _coconut_matmul, _coconut_py_str, _coconut_flatten, _coconut_multiset, _coconut_back_none_pipe, _coconut_back_none_star_pipe, _coconut_back_none_dubstar_pipe, _coconut_forward_none_compose, _coconut_back_none_compose, _coconut_forward_none_star_compose, _coconut_back_none_star_compose, _coconut_forward_none_dubstar_compose, _coconut_back_none_dubstar_compose, _coconut_call_or_coefficient, _coconut_not_in".format(**format_dict),
+        underscore_imports="{tco_comma}{call_set_names_comma}{handle_cls_args_comma}_namedtuple_of, _coconut, _coconut_super, _coconut_Expected, _coconut_MatchError, _coconut_iter_getitem, _coconut_base_compose, _coconut_forward_compose, _coconut_back_compose, _coconut_forward_star_compose, _coconut_back_star_compose, _coconut_forward_dubstar_compose, _coconut_back_dubstar_compose, _coconut_pipe, _coconut_star_pipe, _coconut_dubstar_pipe, _coconut_back_pipe, _coconut_back_star_pipe, _coconut_back_dubstar_pipe, _coconut_none_pipe, _coconut_none_star_pipe, _coconut_none_dubstar_pipe, _coconut_bool_and, _coconut_bool_or, _coconut_none_coalesce, _coconut_minus, _coconut_map, _coconut_partial, _coconut_get_function_match_error, _coconut_base_pattern_func, _coconut_addpattern, _coconut_sentinel, _coconut_assert, _coconut_raise, _coconut_mark_as_match, _coconut_reiterable, _coconut_self_match_types, _coconut_dict_merge, _coconut_exec, _coconut_comma_op, _coconut_multi_dim_arr, _coconut_mk_anon_namedtuple, _coconut_matmul, _coconut_py_str, _coconut_flatten, _coconut_multiset, _coconut_back_none_pipe, _coconut_back_none_star_pipe, _coconut_back_none_dubstar_pipe, _coconut_forward_none_compose, _coconut_back_none_compose, _coconut_forward_none_star_compose, _coconut_back_none_star_compose, _coconut_forward_none_dubstar_compose, _coconut_back_none_dubstar_compose, _coconut_call_or_coefficient, _coconut_in, _coconut_not_in".format(**format_dict),
         import_typing=pycondition(
             (3, 5),
             if_ge="import typing",

coconut/compiler/templates/header.py_template

@@ -469,6 +469,9 @@ def _coconut_bool_and(a, b):
 def _coconut_bool_or(a, b):
     """Boolean or operator (or). Equivalent to (a, b) -> a or b."""
     return a or b
+def _coconut_in(a, b):
+    """Containment operator (in). Equivalent to (a, b) -> a in b."""
+    return a in b
 def _coconut_not_in(a, b):
     """Negative containment operator (not in). Equivalent to (a, b) -> a not in b."""
     return a not in b

coconut/root.py

@@ -26,7 +26,7 @@
 VERSION = "3.0.0"
 VERSION_NAME = None
 # False for release, int >= 1 for develop
-DEVELOP = 19
+DEVELOP = 20
 ALPHA = True  # for pre releases rather than post releases
 
 # -----------------------------------------------------------------------------------------------------------------------

coconut/tests/src/cocotest/agnostic/primary.coco

@@ -1580,4 +1580,7 @@ def primary_test() -> bool:
     assert not a_multiset.values() `isinstance` list
     assert not a_multiset.items() `isinstance` list
     assert len(a_multiset.keys()) == len(a_multiset.values()) == len(a_multiset.items()) == 2
+    assert (in)(1, [1, 2])
+    assert not (1 not in .)([1, 2])
+    assert not (in)([[]], [])
     return True