[plt-scheme] stepper interface suggestion for "start-from-here"?

Slight modifications to the previous proposal:

> 1) Provide a "step" form that opens a Stepper window to evaluate  
> its argument.  This form would be invokable from either Definitions  
> or Interactions.  If invoked when there is no MrEd window open at  
> all, it would simply evaluate its argument.  If invoked from within  
> an expression that's already being Stepped, it would be ignored.

Of course, there's no need for the "step" form to be restricted to  
one expression; if it were written to take an arbitrary number of  
expressions and evaluate them in order, the "Stepper" button would be  
equivalent to wrapping a "step" around the entire Definitions pane  
and hitting "Run".

The miniature "foot" icon would be an abbreviation for the unary form  
of "step", i.e. it would apply only to the immediately-following  
expression.



Stephen Bloch
sbloch at adelphi.edu