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author | Thomas Wouters <thomas@python.org> | 2006-02-27 00:24:13 (GMT) |
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committer | Thomas Wouters <thomas@python.org> | 2006-02-27 00:24:13 (GMT) |
commit | dca3b9c797f6dd4b08d590fa2aa1031e22ab598e (patch) | |
tree | d2b7aa53793110100965906b1266296d08bd4ec1 /Doc/ref/ref5.tex | |
parent | d3a5f53a27be821cfdff869fd8ad93a060497e8c (diff) | |
download | cpython-dca3b9c797f6dd4b08d590fa2aa1031e22ab598e.zip cpython-dca3b9c797f6dd4b08d590fa2aa1031e22ab598e.tar.gz cpython-dca3b9c797f6dd4b08d590fa2aa1031e22ab598e.tar.bz2 |
PEP 308 implementation, including minor refdocs and some testcases. It
breaks the parser module, because it adds the if/else construct as well as
two new grammar rules for backward compatibility. If no one else fixes
parsermodule, I guess I'll go ahead and fix it later this week.
The TeX code was checked with texcheck.py, but not rendered. There is
actually a slight incompatibility:
>>> (x for x in lambda:0)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: iteration over non-sequence
changes into
>>> (x for x in lambda: 0)
File "<stdin>", line 1
(x for x in lambda: 0)
^
SyntaxError: invalid syntax
Since there's no way the former version can be useful, it's probably a
bugfix ;)
Diffstat (limited to 'Doc/ref/ref5.tex')
-rw-r--r-- | Doc/ref/ref5.tex | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/Doc/ref/ref5.tex b/Doc/ref/ref5.tex index 462548f..65a3cff 100644 --- a/Doc/ref/ref5.tex +++ b/Doc/ref/ref5.tex @@ -155,8 +155,7 @@ square brackets: \begin{productionlist} \production{test} - {\token{and_test} ( "or" \token{and_test} )* - | \token{lambda_form}} + {\token{or_test} | \token{lambda_form}} \production{testlist} {\token{test} ( "," \token{test} )* [ "," ]} \production{list_display} @@ -1017,7 +1016,8 @@ Boolean operations have the lowest priority of all Python operations: \begin{productionlist} \production{expression} - {\token{or_test} | \token{lambda_form}} + {\token{or_test} [\token{if} \token{or_test} \token{else} + \token{test}] | \token{lambda_form}} \production{or_test} {\token{and_test} | \token{or_test} "or" \token{and_test}} \production{and_test} @@ -1036,6 +1036,11 @@ The operator \keyword{not} yields \code{True} if its argument is false, \code{False} otherwise. \opindex{not} +The expression \code{\var{x} if \var{C} else \var{y}} first evaluates +\var{C} (\emph{not} \var{x}); if \var{C} is true, \var{x} is evaluated and +its value is returned; otherwise, \var{y} is evaluated and its value is +returned. + The expression \code{\var{x} and \var{y}} first evaluates \var{x}; if \var{x} is false, its value is returned; otherwise, \var{y} is evaluated and the resulting value is returned. |