replace is_windows() function with attribute in mlog

mesonbuild/mlog.py

@@ -30,10 +30,6 @@
     TV_Loggable = T.Union[str, 'AnsiDecorator', StringProtocol]
     TV_LoggableList = T.List[TV_Loggable]
 
-def is_windows() -> bool:
-    platname = platform.system().lower()
-    return platname == 'windows'
-
 def _windows_ansi() -> bool:
     # windll only exists on windows, so mypy will get mad
     from ctypes import windll, byref  # type: ignore
@@ -77,6 +73,8 @@ class _Logger:
 
     _LOG_FNAME: T.ClassVar[str] = 'meson-log.txt'
 
+    is_windows = platform.system().lower() == 'windows'
+
     @contextmanager
     def no_logging(self) -> T.Iterator[None]:
         self.log_disable_stdout = True
@@ -121,7 +119,7 @@ def start_pager(self) -> None:
             pager_cmd = shlex.split(os.environ['PAGER'])
         else:
             less = shutil.which('less')
-            if not less and is_windows():
+            if not less and self.is_windows:
                 git = shutil.which('git')
                 if git:
                     path = Path(git).parents[1] / 'usr' / 'bin'
@@ -388,7 +386,7 @@ def colorize_console(self) -> bool:
         if _colorize_console is not None:
             return _colorize_console
         try:
-            if is_windows():
+            if self.is_windows:
                 _colorize_console = os.isatty(output.fileno()) and _windows_ansi()
             else:
                 _colorize_console = os.isatty(output.fileno()) and os.environ.get('TERM', 'dumb') != 'dumb'
@@ -402,7 +400,7 @@ def setup_console(self) -> None:
         # connected to stdout and turn off ANSI escape processing. Call this after
         # running a subprocess to ensure we turn it on again.
         output = sys.stderr if self.log_to_stderr else sys.stdout
-        if is_windows():
+        if self.is_windows:
             try:
                 delattr(output, 'colorize_console')
             except AttributeError: