Re: [PATCH v2 10/11] qapi/introspect.py: improve readability of _tree_to_qlit

[Markus Armbruster]

John Snow <jsnow@redhat.com> writes:

> Subjective, but I find getting rid of the comprehensions helps. Also,
> divide the sections into scalar and non-scalar sections, and remove
> old-style string formatting.
>
> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  scripts/qapi/introspect.py | 37 +++++++++++++++++++++----------------
>  1 file changed, 21 insertions(+), 16 deletions(-)
>
> diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
> index a261e402d69..d4f28485ba5 100644
> --- a/scripts/qapi/introspect.py
> +++ b/scripts/qapi/introspect.py
> @@ -100,7 +100,7 @@ def indent(level: int) -> str:
>  
>          ret = ''
>          if obj.comment:
> -            ret += indent(level) + '/* %s */\n' % obj.comment
> +            ret += indent(level) + f"/* {obj.comment} */\n"
>          if obj.ifcond:
>              ret += gen_if(obj.ifcond)
>          ret += _tree_to_qlit(obj.value, level, suppress_first_indent)
> @@ -111,31 +111,36 @@ def indent(level: int) -> str:
>      ret = ''
>      if not suppress_first_indent:
>          ret += indent(level)
> +
> +    # Scalars:
>      if obj is None:
>          ret += 'QLIT_QNULL'
>      elif isinstance(obj, str):
> -        ret += 'QLIT_QSTR(' + to_c_string(obj) + ')'
> +        ret += f"QLIT_QSTR({to_c_string(obj)})"
> +    elif isinstance(obj, bool):
> +        ret += "QLIT_QBOOL({:s})".format(str(obj).lower())

Changed from

           ret += 'QLIT_QBOOL(%s)' % ('true' if obj else 'false')

Doesn't look like an improvement to me.

> +
> +    # Non-scalars:
>      elif isinstance(obj, list):
> -        elts = [_tree_to_qlit(elt, level + 1).strip('\n')
> -                for elt in obj]
> -        elts.append(indent(level + 1) + "{}")
>          ret += 'QLIT_QLIST(((QLitObject[]) {\n'
> -        ret += '\n'.join(elts) + '\n'
> +        for value in obj:
> +            ret += _tree_to_qlit(value, level + 1).strip('\n') + '\n'
> +        ret += indent(level + 1) + '{}\n'
>          ret += indent(level) + '}))'
>      elif isinstance(obj, dict):
> -        elts = []
> -        for key, value in sorted(obj.items()):
> -            elts.append(indent(level + 1) + '{ %s, %s }' %
> -                        (to_c_string(key),
> -                         _tree_to_qlit(value, level + 1, True)))
> -        elts.append(indent(level + 1) + '{}')
>          ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n'
> -        ret += ',\n'.join(elts) + '\n'
> +        for key, value in sorted(obj.items()):
> +            ret += indent(level + 1) + "{{ {:s}, {:s} }},\n".format(
> +                to_c_string(key),
> +                _tree_to_qlit(value, level + 1, suppress_first_indent=True)
> +            )
> +        ret += indent(level + 1) + '{}\n'
>          ret += indent(level) + '}))'
> -    elif isinstance(obj, bool):
> -        ret += 'QLIT_QBOOL(%s)' % ('true' if obj else 'false')
>      else:
> -        assert False                # not implemented
> +        raise NotImplementedError(
> +            f"type '{type(obj).__name__}' not implemented"
> +        )

Not covered by the commit message's mandate.

Why bother?

> +
>      if level > 0:
>          ret += ','
>      return ret