JEP325: Switch expressions spec
alex.buckley at oracle.com
Wed Apr 18 19:02:58 UTC 2018
On 4/18/2018 11:16 AM, Kevin Bourrillion wrote:
> Evaluation of an expression can produce side effects, because
> expressions may contain embedded assignments, increment operators,
> decrement operators, and method invocations. *In addition, lambda
> expressions and switch expressions have bodies that may contain
> arbitrary statements.
> A lambda "contains" statements /physically/, but nothing gets
> executed. If anything, it is anonymous /classes/ that belong here
> (though maybe, arguably, that would be covered if "method invocations"
> was changed to "method or constructor invocations"?).
The goal was to highlight that a lambda/switch expression is not like
(say) a field access expression, because of the ability to have a body
of statements rather than merely a tree of subexpressions ... but you're
right, "Evaluation of a lambda expression is distinct from execution of
the lambda body." (JLS 15.27.4)
> Suggestion: "... because expressions may contain embedded assignments,
> increment operators, decrement operators, and method or constructor
> invocations, as well as arbitrary statements nested inside a switch
Yes, limiting the arbitrariness to switch expressions (the sole "home"
for something-resembling-block-expressions) is right.
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