I feel like make-evaluator should do something like this when you call (make-evaluator ‘(special beginner)). Is there a reason that it doesn’t?
On Apr 14, 2014, at 5:43 PM, Matthias Felleisen <matth...@ccs.neu.edu> wrote: > > On Apr 14, 2014, at 1:04 PM, Klaus Ostermann <klaus...@gmail.com> wrote: > >> I'm using Scribble to write lecture notes on the "Beginning Student >> Language". >> >> To this end, I'm using >> >> @(require (for-label lang/htdp-beginner)) >> >> to get the bindings for the functions defined in BSL. >> >> However, if I want to illustrate an error, I get the wrong error message. >> >> For instance, >> >> @ex[(number->string "asdf")] >> >> gives the ouput: >> >>> (number->string "asdf") >> >> number->string: contract violation >> expected: number? >> given: "asdf" >> >> >> rather than the expected: >> >>> (number->string "asdf") >> >> number->string: expects a number, given "asdf" >> >> What do I need to do to get the BSL error messages? > > ;; Here is the code from the shared library in HtDP/2e: > > (require teachpack/2htdp/scribblings/img-eval) > > (define-syntax-rule > (*sl-eval module-lang reader def ...) > ;; ===>>> > (let () > (define me (parameterize ([sandbox-propagate-exceptions #f]) > (make-img-eval))) > (me '(require (only-in racket empty? first rest cons? sqr true false))) > (me '(require lang/posn)) > (me '(require racket/pretty)) > (me '(current-print pretty-print-handler)) > (me '(pretty-print-columns 65)) > (me 'def) > ... > (call-in-sandbox-context me (lambda () (error-print-source-location #f))) > (call-in-sandbox-context me (lambda () (sandbox-output 'string))) > (call-in-sandbox-context me (lambda () (sandbox-error-output 'string))) > (call-in-sandbox-context me (lambda () (sandbox-propagate-exceptions #f))) > (call-in-sandbox-context me (lambda () > (current-print-convert-hook > (let ([prev (current-print-convert-hook)]) > ;; tell `print-convert' to leave images > as themselves: > (lambda (v basic sub) > (if (convertible? v) > v > (prev v basic sub))))) > > (pretty-print-size-hook > (let ([prev (pretty-print-size-hook)]) > ;; tell `pretty-print' that we'll handle > images specially: > (lambda (v w? op) > (if (convertible? v) 1 (prev v w? > op))))) > > (pretty-print-print-hook > (let ([prev (pretty-print-print-hook)]) > ;; tell `pretty-print' how to handle > images, which is > ;; by using `write-special': > (lambda (v w? op) > (if (convertible? v) (write-special v > op) (prev v w? op))))) > > ((dynamic-require 'htdp/bsl/runtime > 'configure) > (dynamic-require reader 'options)))) > (call-in-sandbox-context me (lambda () (namespace-require module-lang))) > (interaction-eval #:eval me (require 2htdp/image)) > (interaction-eval #:eval me (require 2htdp/batch-io)) > (error-display-handler > (lambda (msg exn) > (if (exn? exn) > (display (get-rewriten-error-message exn) (current-error-port)) > (eprintf "uncaught exception: ~e" exn)))) > me)) > > (require lang/private/rewrite-error-message) > > (define-syntax-rule > (bsl-eval def ...) > (*sl-eval 'lang/htdp-beginner 'htdp/bsl/lang/reader def ...)) > > ;; Here is how I use this in chapter 1 to get error messages: > > @interaction[#:eval (bsl-eval) > (string-length 42) > ] > > > It's not perfect but it comes reasonably close in most cases. > > -- Matthias > > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
