D has a few ways of writing lambda expressions / anonymous
functions:
x => doSomething()
{ doSomething(); }
(){ doSomething(); }
While the flexibility is great, there's a hidden issue for those
programmers who come from different languages and are used to
writing:
x => { doSomething(); doSomethingElse(); }
At first glance, this may seem okay but what's actually happening
is that this is a lambda returning a lambda. The correct way
would be to rewrite this as one of:
x => { doSomething(); doSomethingElse(); }()
(x){ doSomething(); doSomethingElse(); }
This particular issue as popped up twice in the last couple days
alone and presumably many more times in the past:
http://forum.dlang.org/thread/qsayoktyffczskrnm...@forum.dlang.org
http://forum.dlang.org/thread/thgyqyarccinzuqhc...@forum.dlang.org
I'm proposing that we add a warning to the compiler for this
particular case. If the programmer intended to return a lambda,
then rewrite the expression as one of:
x => (){ doSomething(); doSomethingElse(); }
x => ({ doSomething(); doSomethingElse(); })
