PEP-0318, @decorator-style. In Guido's words:
"@ seems the syntax that everybody can hate equally"
Implementation by Mark Russell, from SF #979728.
diff --git a/Doc/ref/ref7.tex b/Doc/ref/ref7.tex
index 80ddc33..1d7b860 100644
--- a/Doc/ref/ref7.tex
+++ b/Doc/ref/ref7.tex
@@ -315,8 +315,12 @@
\begin{productionlist}
\production{funcdef}
- {"def" \token{funcname} "(" [\token{parameter_list}] ")"
+ {[\token{decorators}] "def" \token{funcname} "(" [\token{parameter_list}] ")"
":" \token{suite}}
+ \production{decorators}
+ {\token{decorator} ([NEWLINE] \token{decorator})* NEWLINE}
+ \production{decorator}
+ {"@" \token{dotted_name} ["(" [\token{argument_list} [","]] ")"]}
\production{parameter_list}
{(\token{defparameter} ",")*}
\productioncont{("*" \token{identifier} [, "**" \token{identifier}]}
@@ -343,6 +347,27 @@
The function definition does not execute the function body; this gets
executed only when the function is called.
+A function definition may be wrapped by one or more decorator expressions.
+Decorator expressions are evaluated when the function is defined, in the scope
+that contains the function definition. The result must be a callable,
+which is invoked with the function object as the only argument.
+The returned value is bound to the function name instead of the function
+object. If there are multiple decorators, they are applied in reverse
+order. For example, the following code:
+
+\begin{verbatim}
+@f1
+@f2
+def func(): pass
+\end{verbatim}
+
+is equivalent to:
+
+\begin{verbatim}
+def func(): pass
+func = f2(f1(func))
+\end{verbatim}
+
When one or more top-level parameters have the form \var{parameter}
\code{=} \var{expression}, the function is said to have ``default
parameter values.'' For a parameter with a