[plt-scheme] starting DrScheme with no language level chosen

On Dec 4, 2005, at 11:50 AM, Robby Findler wrote:

> The most frequent bug report we get (by far) is "DrScheme does not
> allow dotted pairs" or "DrScheme does not allow set!" followed by
> comments along the lines of "how can you call this 'scheme'" etc. The
> problem is, of course, that these people do not realize that they need
> to pick an appropriate language level. This next release is our new
> attempt to combat that problem. I suspect that hiding the message
> telling people to choose the language level probably would not work in
> our favor in this case.
>
> In partial answer to the use-case you mention below (where someone
> changes the language immediately, perhaps without even reading the  
> text
> at the bottom), you will note that anything do uses the new language,
> except type a program in the REPL but the REPL tells you that you
> should click Run to get your newly selected language.
>
> Robby

Being relatively new to Scheme (and certainly DrScheme), I often find  
myself wondering which language to use and, for that matter, what is  
standard and what is not. I only noticed this morning that if I  
choose "Swindle" then I can go ahead and use call/cc as a synonym for  
call-with-current-continuation (without defining it, that is). I  
still wonder about the letcc used systematically in "The Seasoned  
Schemer". I think I can manage to translate the examples, but it is a  
bit of an adventure trying to figure out what dialect you need, or  
how code needs to be modified before it can be run.

===
Gregory Woodhouse
gregory.woodhouse at sbcglobal.net

"Perfection is achieved, not when there is nothing more to add, but  
when there is nothing left to take away."
-- Antoine de Saint-Exupery