Rainer Blome wrote:

...

You can get 90% of 'if bool then else': if: bool Then: thenClause Else: elseClause = ( bool if: thenClause False: elseClause ).

Oh, OK. In this case, a macro would indeed be an efficiency hack. Because using a message would give up locality there. Where is the `if:Then:Else:' slot? In globalBehavior, I guess. And that slot takes time to find. If its content is a normal method, it will be evaluated over and over again. Maybe the compiler can optimize that away, but I don't think so.

Well, I couldn't let *that* bait go :-) Here's a little experiment: put the if: .. method in defaultBehavior and create a test object called foo containing

(| parent* = defaultBehavior*. test: n With: x With: y = ( n do: [ x < y ifTrue: 'true' False: 'false'] ). test2: n With: x With: y = ( n do: [ if: x < y Then: 'true' Else: 'false'] ). |)

[Hint: never put such testing code in the shell, because it has a dynamic parent that can mess up performance.]

On my system, [foo test: 100000 With: 3 With: 4] time is 135..161 and [foo test2: 100000 With: 3 With: 4] time is 137..162.

No difference.

Of course, a *really* smart compiler would execute both in 0 ms, but that's another story.

-Urs