Move error handling to common

my/kython/kerror.py

@@ -1,114 +0,0 @@
-from typing import Union, TypeVar, Iterator, Callable, Iterable, List, Tuple, Type
-
-
-T = TypeVar('T')
-E = TypeVar('E', bound=Exception)
-
-ResT = Union[T, E]
-
-Res = ResT[T, Exception]
-
-
-# TODO make it a bit more typed??
-def is_error(res: Res[T]) -> bool:
-    return isinstance(res, Exception)
-
-
-def is_ok(res: Res[T]) -> bool:
-    return not is_error(res)
-
-
-def unwrap(res: Res[T]) -> T:
-    if isinstance(res, Exception):
-        raise res
-    else:
-        return res
-
-
-def split_errors(l: Iterable[ResT[T, E]], ET=Exception) -> Tuple[List[T], List[E]]:
-    rl: List[T] = []
-    el: List[E] = []
-    for x in l:
-        if isinstance(x, ET):
-            el.append(x)
-        else:
-            rl.append(x) # type: ignore
-    return rl, el
-
-
-def ytry(cb) -> Iterator[Exception]:
-    try:
-        cb()
-    except Exception as e:
-        yield e
-
-
-# TODO experimental, not sure if I like it
-def echain(ex: E, cause: Exception) -> E:
-    ex.__cause__ = cause
-    # TODO assert cause is none?
-    # TODO copy??
-    return ex
-    # try:
-    #     # TODO is there a awy to get around raise from?
-    #     raise ex from cause
-    # except Exception as e:
-    #     if isinstance(e, type(ex)):
-    #         return e
-    #     else:
-    #         raise e
-
-
-def sort_res_by(items: Iterable[ResT], key) -> List[ResT]:
-    """
-    The general idea is: just alaways carry errors with the entry that precedes them
-    """
-    # TODO ResT object should hold exception class?...
-    group = []
-    groups = []
-    for i in items:
-        if isinstance(i, Exception):
-            group.append(i)
-        else:
-            groups.append((i, group))
-            group = []
-
-    results = []
-    for v, errs in sorted(groups, key=lambda p: key(p[0])):
-        results.extend(errs)
-        results.append(v)
-    results.extend(group)
-
-    return results
-
-
-def test_sort_res_by():
-    class Exc(Exception):
-        def __eq__(self, other):
-            return self.args == other.args
-
-    ress = [
-        Exc('first'),
-        Exc('second'),
-        5,
-        3,
-        Exc('xxx'),
-        2,
-        1,
-        Exc('last'),
-    ]
-    results = sort_res_by(ress, lambda x: x) # type: ignore
-    assert results == [
-        1,
-        Exc('xxx'),
-        2,
-        3,
-        Exc('first'),
-        Exc('second'),
-        5,
-        Exc('last'),
-    ]
-
-    results2 = sort_res_by(ress + [0], lambda x: x) # type: ignore
-    assert results2 == [Exc('last'), 0] + results[:-1]
-