The `make-evaluator' function just `require's the specified module into the sandbox's namespace. It doesn't set up reading or printing.
The most important part of the code fragment below is ((dynamic-require 'htdp/bsl/runtime 'configure) (dynamic-require reader 'options)) which triggers the run-time configuration of the `htdp/*sl' languages, which sets reading and printing parameters. All of this is a step on the way to an improved `make-evaluator' that is like using `#lang' or picking a language with `racket -I ...', but no one has filled in the pieces, yet. At Mon, 27 Feb 2012 09:59:47 -0600, Robby Findler wrote: > Why is make-evaluator insufficient? > > On Mon, Feb 27, 2012 at 9:55 AM, Matthias Felleisen > <matth...@ccs.neu.edu> wrote: > > > > I was wrong. The code below accomplishes what you want. It sets up an > evaluator in the *sl languages, including hooks to print #t and #f properly. > > > > (Matthew reminded me but I had to re-run the rendering script in a clean > directory to validate his reminder.) > > > > > > > > (define-syntax-rule > > (*sl-eval module-lang reader def ...) > > ;; ===>>> > > (let () > > (define me (make-base-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 () > > (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)) > > ;; --- splice in the defs > > me)) > > > > (define-syntax-rule > > (bsl-eval def ...) > > (*sl-eval 'lang/htdp-beginner 'htdp/bsl/lang/reader def ...)) > > > > (define-syntax-rule > > (bsl-eval+ def ...) > > (*sl-eval 'lang/htdp-beginner-abbr 'htdp/bsl+/lang/reader def ...)) > > > > (define-syntax-rule > > (isl-eval def ...) > > (*sl-eval 'lang/htdp-intermediate 'htdp/isl/lang/reader def ...)) > > > > (define-syntax-rule > > (isl-eval+ def ...) > > (*sl-eval 'lang/htdp-intermediate-lambda 'htdp/isl/lang/reader def ...)) > > > > > > > > > > > > On Feb 27, 2012, at 10:31 AM, Robby Findler wrote: > > > >> Should consider this a bug (that that the call to make-evaluator below > >> doesn't set things up properly for this usecase)? > >> > >> Robby > >> > >> On Mon, Feb 27, 2012 at 9:27 AM, Matthias Felleisen > >> <matth...@ccs.neu.edu> wrote: > >>> > >>> I am running a short filter function on the output that changes #t to > >>> true. > -- Matthias > >>> > >>> > >>> > >>> On Feb 27, 2012, at 10:23 AM, Klaus Ostermann wrote: > >>> > >>>> Hi all, > >>>> > >>>> I want to use Scribble for some lecture notes using HTDP/2e. > >>>> > >>>> The example "An Introduction to Racket with Pictures" illustrates how to > use Scribble and embed Racket evaluation. However, the HTDP > >>>> languages behave different in some ways - for instance, they > >>>> print "#t" as "true" and various other differences. > >>>> > >>>> How can I use Scribble to write about examples in the HTDP languages? > >>>> I want the exact behavior of the HTDP languages. Using, say, > >>>> (make-evaluator 'lang/htdp-intermediate) > >>>> is not sufficient. > >>>> > >>>> HTDP/2e itself seems to be written using Scribble, which would mean that > there is already a solution to this problem (?). > >>>> > >>>> Regards, > >>>> Klaus > >>>> ____________________ > >>>> Racket Users list: > >>>> http://lists.racket-lang.org/users > >>> > >>> > >>> ____________________ > >>> Racket Users list: > >>> http://lists.racket-lang.org/users > > > > > > ____________________ > > Racket Users list: > > http://lists.racket-lang.org/users > > ____________________ > Racket Users list: > http://lists.racket-lang.org/users ____________________ Racket Users list: http://lists.racket-lang.org/users
