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.


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