Mercurial > octave-nkf
changeset 18876:e6a4fa91a2f1 stable
doc: Clarify order of evaluation of compound assignment expressions
* expr.txi: Add descriptive text and example to clarify the actual order
of evaluation of assignment expressions that contain another assignment
expression.
| author | Mike Miller <mtmiller@ieee.org> |
|---|---|
| date | Tue, 17 Jun 2014 23:38:49 -0400 |
| parents | dd34502e5c3c |
| children | 77d5e7661b8e |
| files | doc/interpreter/expr.txi |
| diffstat | 1 files changed, 13 insertions(+), 2 deletions(-) [+] |
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--- a/doc/interpreter/expr.txi Tue Jun 17 12:04:18 2014 -0400 +++ b/doc/interpreter/expr.txi Tue Jun 17 23:38:49 2014 -0400 @@ -1237,8 +1237,19 @@ @end example @noindent -where @var{op} can be either @code{+}, @code{-}, @code{*}, or @code{/}. -So, the expression +where @var{op} can be either @code{+}, @code{-}, @code{*}, or @code{/}, +as long as @var{expr2} is a simple expression with no side effects. If +@var{expr2} also contains an assignment operator, then this expression +is evaluated as + +@example +@var{temp} = @var{expr2} +@var{expr1} = (@var{expr1}) @var{op} @var{temp} +@end example + +@noindent +where @var{temp} is a placeholder temporary value storing the computed +result of evaluating @var{expr2}. So, the expression @example a *= b+1