Query: optimize arithmetic operation on constants

[maumar]

Currently when we translate Substring on SqlServer into something like this:

SUBSTRING([c].[ContactName], 1 + 1, 3)

we should simplify 1+1 into 2

[AndriySvyryd]

Only when we are sure that the server operation would produce the same result

[michalczerwinski]

@ajcvickers: is this something I can help with?

I was thinking about adding some new visitor in QueryTranslationPreprocessor and while traversing expression detect and optimize some simple cases, like basic arithmetic operations where all arguments are Expression.Constant

Is this in accordance with your vision?

[smitpatel]

This is post translation phase, not pre.

[michalczerwinski]

Ok, thanks @smitpatel. Then QueryTranslationPostprocessor.cs that is.
Just curious, why should be do it in postprocessing, not pre? And more importantly, can I take it?