racket - DrRacket EOPL Scheme output -

i working through eopl scheme exercises using drracket in windows 7. when switch #lang racket #lang eopl, output definitions pane no longer shows in interaction pane. clear, trivial example, running

     #lang racket     4

produces

     4     >  

as expect. running

     #lang eopl     4

produces

     > 

is there can change behavior or there pane should looking @ output? can, of course, evaluate expressions in interaction pane , see output, tedious when have multiple expressions want evaluate multiple times.

looks #lang eopl uses #%plain-module-begin, not print results, instead of #%module-begin, print results.

for quick way switch, create following file following contents:

eopl-printing.rkt:

#lang racket (require (except-in eopl #%module-begin)) (provide (all-from-out eopl)) (provide #%module-begin) 

then use language in file:

#lang s-exp "eopl-printing.rkt" 1 2 3 

produces in drracket:

welcome drracket, version 5.3.4.6 [3m]. language: s-exp "eopl-printing.rkt" [custom]. 1 2 3 >  

caveat: if eopl hiding results reason, may spurious output, don't know sure.