[plt-scheme] Square braces in MrEd

> Forgive the stupid question, but how to enter [ or ] in MrEd then?
> Everytime I try, it gets replaced by ( and ).

In DrScheme preferences, go to the "Editing" tab and the "Scheme" sub- 
tab and uncheck "Automatically adjust opening square brackets".

On a semi-related note, having "Automatically adjust closing parens"  
checked can be quite useful. This automatically changes closing  
parentheses so they match the next unclosed opening parenthesis on the  
left of the cursor. For example, type "[)" and it'll get corrected to  
"[]".

Cheers,

-- Dave