Re: [PATCH 13/37] qapi/common.py: add notational type hints

[Markus Armbruster]

Question on the subject line: what makes a type hint notational?

John Snow <jsnow@redhat.com> writes:

> Signed-off-by: John Snow <jsnow@redhat.com>
> ---
>  scripts/qapi/common.py | 27 ++++++++++++++++-----------
>  1 file changed, 16 insertions(+), 11 deletions(-)
>
> diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
> index 4c079755d3..af01348b35 100644
> --- a/scripts/qapi/common.py
> +++ b/scripts/qapi/common.py
> @@ -12,6 +12,7 @@
>  # See the COPYING file in the top-level directory.
>  
>  import re
> +from typing import Optional, Union, Sequence
>  
>  
>  EATSPACE = '\033EATSPACE.'
> @@ -22,7 +23,7 @@
>  # ENUMName -> ENUM_NAME, EnumName1 -> ENUM_NAME1
>  # ENUM_NAME -> ENUM_NAME, ENUM_NAME1 -> ENUM_NAME1, ENUM_Name2 -> ENUM_NAME2
>  # ENUM24_Name -> ENUM24_NAME
> -def camel_to_upper(value):
> +def camel_to_upper(value: str) -> str:
>      c_fun_str = c_name(value, False)
>      if value.isupper():
>          return c_fun_str
> @@ -41,7 +42,9 @@ def camel_to_upper(value):
>      return new_name.lstrip('_').upper()
>  
>  
> -def c_enum_const(type_name, const_name, prefix=None):
> +def c_enum_const(type_name: str,
> +                 const_name: str,
> +                 prefix: Optional[str] = None) -> str:
>      if prefix is not None:
>          type_name = prefix
>      return camel_to_upper(type_name) + '_' + c_name(const_name, 
> False).upper()
> @@ -56,7 +59,7 @@ def c_enum_const(type_name, const_name, prefix=None):
>  # into substrings of a generated C function name.
>  # '__a.b_c' -> '__a_b_c', 'x-foo' -> 'x_foo'
>  # protect=True: 'int' -> 'q_int'; protect=False: 'int' -> 'int'
> -def c_name(name, protect=True):
> +def c_name(name: str, protect: bool = True) -> str:
>      # ANSI X3J11/88-090, 3.1.1
>      c89_words = set(['auto', 'break', 'case', 'char', 'const', 'continue',
>                       'default', 'do', 'double', 'else', 'enum', 'extern',
> @@ -134,24 +137,24 @@ def pop(self, amount: int = 4) -> int:
>  
>  # Generate @code with @kwds interpolated.
>  # Obey INDENT level, and strip EATSPACE.
> -def cgen(code, **kwds):
> +def cgen(code: str, **kwds: Union[str, int]) -> str:

Hmm.

The @kwds values can be anything, provided they match the conversion
specifiers in @code:

>      raw = code % kwds

Your type hint adds a restriction that wasn't there before.

Is there a better way?

>      if INDENT:
>          raw, _ = re.subn(r'^(?!(#|$))', str(INDENT), raw, flags=re.MULTILINE)
>      return re.sub(re.escape(EATSPACE) + r' *', '', raw)
>  
>  
> -def mcgen(code, **kwds):
> +def mcgen(code: str, **kwds: Union[str, int]) -> str:

Likewise.

>      if code[0] == '\n':
>          code = code[1:]
>      return cgen(code, **kwds)
>  
>  
> -def c_fname(filename):
> +def c_fname(filename: str) -> str:
>      return re.sub(r'[^A-Za-z0-9_]', '_', filename)
>  
>  
> -def guardstart(name):
> +def guardstart(name: str) -> str:
>      return mcgen('''
>  #ifndef %(name)s
>  #define %(name)s
> @@ -160,7 +163,7 @@ def guardstart(name):
>                   name=c_fname(name).upper())
>  
>  
> -def guardend(name):
> +def guardend(name: str) -> str:
>      return mcgen('''
>  
>  #endif /* %(name)s */
> @@ -168,7 +171,7 @@ def guardend(name):
>                   name=c_fname(name).upper())
>  
>  
> -def gen_if(ifcond):
> +def gen_if(ifcond: Sequence[str]) -> str:
>      ret = ''
>      for ifc in ifcond:
>          ret += mcgen('''
> @@ -177,7 +180,7 @@ def gen_if(ifcond):
>      return ret
>  
>  
> -def gen_endif(ifcond):
> +def gen_endif(ifcond: Sequence[str]) -> str:
>      ret = ''
>      for ifc in reversed(ifcond):
>          ret += mcgen('''
> @@ -186,7 +189,9 @@ def gen_endif(ifcond):
>      return ret
>  
>  
> -def build_params(arg_type, boxed, extra=None):
> +def build_params(arg_type,
> +                 boxed: bool,
> +                 extra: Optional[str] = None) -> str:
>      ret = ''
>      sep = ''
>      if boxed: