def ... decorate

Roman Suzi rnd at onego.ru
Fri Aug 13 18:55:39 CEST 2004


Bingo!

Just replace decorate with "from" and the nice syntax is found:

    def f:
        staticmethod
        grammarrule('statement : expression')
        version("Added in 2.4")
        deprecatedmethod
        type_(None)
    from self, p:
        """docstring here"""
        print p[1]

or special short variant for one-liners:

    def n staticmethod from (self, p): return p[1]

(Though I wonder why not just

    n = staticmethod(lambda self, p: p[1])

)


(I've added details to the PythonDecorators wiki)

On Fri, 13 Aug 2004, Skip Montanaro wrote:

>>>>>> "Nick" == Nick Craig-Wood <nick at craig-wood.com> writes:
>
>    Steven> decorate:
>    Steven>     grammarrule('statement : expression')
>    Steven>     versioninfo("Added in 2.4")
>    Steven>     deprecated
>    Steven>     typeinfo(None)
>    Steven> def p_statement_expr(self, p):
>    Steven>     print p[1]
>
>    Nick>  as:
>    Nick>      staticmethod
>    Nick>      grammarrule('statement : expression')
>    Nick>      version("Added in 2.4")
>    Nick>      deprecatedmethod
>    Nick>      type_(None)
>    Nick>  def p_statement_expr(self, p):
>    Nick>      print p[1]
>
>How about
>
>    def p_statement_expr:
>        staticmethod
>        grammarrule('statement : expression')
>        version("Added in 2.4")
>        deprecatedmethod
>        type_(None)
>    decorate (self, p):
>        """docstring here"""
>        print p[1]
>
>Read it something like "define a function named p_statement_expr using a
>bunch of functions to decorate the basic function".
>
>It solves a couple problems:
>
>1. "def" introduces the function definition instead of an arbitrary number
>   of @-expressions.
>
>2. There is no extra indentation of the main body.
>
>3. The name of the function is known early on.
>
>4. "def"/"decorate" pair up visually much the same as "try"/"except" or
>   "if"/"then", though they don't represent alternative blocks of code to be
>   executed.
>
>On the minus side it introduces a vertical separation between the function
>name and parameter list and introduces a new keyword, "decorate".
>
>>From a parsing standpoint I think it will work.  You'll see either a colon
>or a left paren after the function name to distinguish between the two types
>of function definition.  I'm not sure if a token needs to be used to
>separate the various decorator functions or if requiring a newline and
>indentation is sufficient.
>
>Skip
>

Sincerely yours, Roman Suzi
-- 
rnd at onego.ru =\= My AI powered by GNU/Linux RedHat 7.3



More information about the Python-list mailing list