Re: [PATCH 09/22] qapi: add match_nofail helper

[John Snow]

On 4/25/21 3:54 AM, Markus Armbruster wrote:
> John Snow <jsnow@redhat.com> writes:
>
> > Mypy cannot generally understand that these regex functions cannot
> > possibly fail. Add a _nofail helper that clarifies this for mypy.
>
> Convention wants a blank line here.

Tooling failure.

stg pop -a
while stg push; and stg edit --sign; done

(Will fix, but not so sure about fixing the tool...)

> > Signed-off-by: John Snow <jsnow@redhat.com>
> > ---
> >   scripts/qapi/common.py |  8 +++++++-
> >   scripts/qapi/main.py   |  6 ++----
> >   scripts/qapi/parser.py | 13 +++++++------
> >   3 files changed, 16 insertions(+), 11 deletions(-)
> >
> > diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
> > index cbd3fd81d36..d38c1746767 100644
> > --- a/scripts/qapi/common.py
> > +++ b/scripts/qapi/common.py
> > @@ -12,7 +12,7 @@
> >   # See the COPYING file in the top-level directory.
> >   
> >   import re
> > -from typing import Optional, Sequence
> > +from typing import Match, Optional, Sequence
> >   
> >   
> >   #: Magic string that gets removed along with all space to its right.
> > @@ -210,3 +210,9 @@ def gen_endif(ifcond: Sequence[str]) -> str:
> >   #endif /* %(cond)s */
> >   ''', cond=ifc)
> >       return ret
> > +
> > +
> > +def match_nofail(pattern: str, string: str) -> Match[str]:
> > +    match = re.match(pattern, string)
> > +    assert match is not None
> > +    return match
>
> Name it must_match()?  You choose.

If you think it reads genuinely better, sure.

> I wish we could have more stating typing with less notational overhead,
> but no free lunch...
>
> [...]