An imperative block without a return statement returns null #2

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1. pboyer

   added

   TODO

   on May 31, 2016
2. lukechurch commented on May 31, 2016

   

   lukechurch

   on May 31, 2016

   Contributor

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   (Let me know if me answering these ever gets unhelpful)

   The design was that it should return null.

   Whilst this is a little bit annoying and slightly harms exploration, it does mean that it's less fragile to changes in the ordering of the code and makes it slightly more predictable.

   It's tangled to a broader issue that I now consider a mistake that DesignScript has statements at all rather than everything being an expression. Consequently if we had it return the last expression there'd be all sorts of ugly things to deal with:

   r = [Imperative]  {
   a = 2;
   if (false) { print ("Woof"); } else { print "Meow"; )
   }
   

   Which is the 'last expression'? I think valid arguments could be made for '2', 'false' and "Meow".
   "Last assigned variable" might be a workable alternative, and then you only have to decide what happens with scoping etc.

   This all got far too messy, so we went with null.
3. pboyer commented on Jun 1, 2016

   

   pboyer

   on Jun 1, 2016

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   That sounds very reasonable. Thanks @lukechurch!
4. pboyer

   changed the title [-]What happens when an imperative block lacks a return? Return last expr?[/-] [+]What happens when an imperative block lacks a return?[/+] on Jun 1, 2016
5. pboyer

   removed

   TODO

   on Oct 27, 2016
6. pboyer

   closed this as completedon Oct 31, 2016
7. pboyer

   reopened this on Oct 31, 2016
8. pboyer

   changed the title [-]What happens when an imperative block lacks a return?[/-] [+]An imperative block without a return statement returns null[/+] on Oct 31, 2016