diff options
Diffstat (limited to 'Doc/ref/ref6.tex')
| -rw-r--r-- | Doc/ref/ref6.tex | 42 |
1 files changed, 26 insertions, 16 deletions
diff --git a/Doc/ref/ref6.tex b/Doc/ref/ref6.tex index 04db013..1fc885e 100644 --- a/Doc/ref/ref6.tex +++ b/Doc/ref/ref6.tex @@ -108,7 +108,8 @@ objects: \begin{productionlist} \production{assignment_stmt} - {(\token{target_list} "=")+ \token{expression_list}} + {(\token{target_list} "=")+ + (\token{expression_list} | \token{yield_expression})} \production{target_list} {\token{target} ("," \token{target})* [","]} \production{target} @@ -273,11 +274,11 @@ operation and an assignment statement: \begin{productionlist} \production{augmented_assignment_stmt} - {\token{target} \token{augop} \token{expression_list}} + {\token{target} \token{augop} + (\token{expression_list} | \token{yield_expression})} \production{augop} {"+=" | "-=" | "*=" | "/=" | "\%=" | "**="} - % The empty groups below prevent conversion to guillemets. - \productioncont{| ">{}>=" | "<{}<=" | "\&=" | "\textasciicircum=" | "|="} + \productioncont{| ">>=" | "<<=" | "\&=" | "\textasciicircum=" | "|="} \end{productionlist} (See section~\ref{primaries} for the syntax definitions for the last @@ -376,9 +377,9 @@ right type (but even this is determined by the sliced object). \begin{productionlist} \production{print_stmt} - {"print" ( \optional{\token{expression} ("," \token{expression})* \optional{","}}} + {"print" ([\token{expression} ("," \token{expression})* [","]} \productioncont{| ">>" \token{expression} - \optional{("," \token{expression})+ \optional{","}} )} + [("," \token{expression})+ [","])} \end{productionlist} \keyword{print} evaluates each expression in turn and writes the @@ -460,7 +461,7 @@ to include an \grammartoken{expression_list}. In that context, a bare \begin{productionlist} \production{yield_stmt} - {"yield" \token{expression_list}} + {\token{yield_expression}} \end{productionlist} \index{generator!function} @@ -630,15 +631,19 @@ It continues with the next cycle of the nearest enclosing loop. \production{import_stmt} {"import" \token{module} ["as" \token{name}] ( "," \token{module} ["as" \token{name}] )*} - \productioncont{| "from" \token{module} "import" \token{identifier} + \productioncont{| "from" \token{relative_module} "import" \token{identifier} ["as" \token{name}]} \productioncont{ ( "," \token{identifier} ["as" \token{name}] )*} - \productioncont{| "from" \token{module} "import" "(" \token{identifier} - ["as" \token{name}]} + \productioncont{| "from" \token{relative_module} "import" "(" + \token{identifier} ["as" \token{name}]} \productioncont{ ( "," \token{identifier} ["as" \token{name}] )* [","] ")"} \productioncont{| "from" \token{module} "import" "*"} \production{module} {(\token{identifier} ".")* \token{identifier}} + \production{relative_module} + {"."* \token{module} | "."+} + \production{name} + {\token{identifier}} \end{productionlist} Import statements are executed in two steps: (1) find a module, and @@ -757,8 +762,10 @@ before the release in which the feature becomes standard. \begin{productionlist}[*] \production{future_statement} - {"from" "__future__" "import" feature ["as" name] ("," feature ["as" name])*} - \productioncont{| "from" "__future__" "import" "(" feature ["as" name] ("," feature ["as" name])* [","] ")"} + {"from" "__future__" "import" feature ["as" name]} + \productioncont{ ("," feature ["as" name])*} + \productioncont{| "from" "__future__" "import" "(" feature ["as" name]} + \productioncont{ ("," feature ["as" name])* [","] ")"} \production{feature}{identifier} \production{name}{identifier} \end{productionlist} @@ -775,9 +782,10 @@ lines that can appear before a future statement are: \end{itemize} -The features recognized by Python 2.3 are \samp{generators}, -\samp{division} and \samp{nested_scopes}. \samp{generators} and -\samp{nested_scopes} are redundant in 2.3 because they are always +The features recognized by Python 2.5 are \samp{absolute_import}, +\samp{division}, \samp{generators}, \samp{nested_scopes} and +\samp{with_statement}. \samp{generators} and \samp{nested_scopes} +are redundant in Python version 2.3 and above because they are always enabled. A future statement is recognized and treated specially at compile @@ -872,7 +880,7 @@ containing the \keyword{exec} statement. The same applies to the \begin{productionlist} \production{exec_stmt} - {"exec" \token{expression} + {"exec" \token{or_expr} ["in" \token{expression} ["," \token{expression}]]} \end{productionlist} @@ -916,3 +924,5 @@ for use by \keyword{exec}. + + |