[racket] Use of map and eval to evaluate symbol in namespace

Then would something like this work?
#lang racket

(provide (all-defined-out)
         #%datum #%top
         (rename-out [new-module-begin #%module-begin]))

(define-syntax-rule
  (new-module-begin med-thing ...)
  (#%module-begin (displayln (parse-meds (list med-thing ...)))))

(define (parse-meds lst)
  (match lst
    [(list) ""]
    [(list-rest MED QUANT FORM POS (? inst? INST) rest)
     (~a MED " " line " " QUANT " " FORM "\n" POS "\n" INST "\n" (parse rest))]
    [(list-rest MED QUANT FORM POS rest)
     (~a MED " " line " " QUANT " " FORM "\n" POS "\n" (parse rest))]))

(define hctz25 "Hydrochlorothiazide 25mg")
(define simva20 "Simvastatin 20mg")
(define pl "pills")
(define 1xd "Take 1 pill P.O. 1x/day")
(define 1xn "Take 1 pill P.O. 1x at night")
(define INSTOMZ "half an hour before breakfast, with a glass of water")
(define line "-----------")

(define (inst? x)
  (equal? x INSTOMZ))


On Aug 4, 2014, at 1:22 AM, Henry Lenzi <henry.lenzi at gmail.com> wrote:

> Hello Alex --
> 
> This is nice, the problem is separating the output into the proper
> formatting. I feel this has to be done a step before the expansion
> into the string form.
> One thing I'm considering is that that the DSL is made of MED QUANT
> FORM POS or MED QUANT FOR POS INST, so 4 or 5 items.
> If we have a symbol list (before string expansion), than we can treat
> INST as the divider marker. Otherwise, there's a linebreak at every
> fourth item.
> 
> I'm looking into how to to this using a position function:
> (define (position item list)
>    (- (length list)
>       (length (member item list))))
> 
> Knowing where the INST instructions occur help up decided whether we
> can break a line into the
> MED QUANT FORM
> POS
> or
> MED QUANT FORM
> POS
> INST
> 
> forms (see the code snippet on http://pasterack.org/pastes/14535 )
> 
> 
> Cheers,
> 
> Henry
> 
> On Mon, Aug 4, 2014 at 1:23 AM, Alexander D. Knauth
> <alexander at knauth.org> wrote:
>> Would this work for what you want?
>> 
>> If med.rkt contains this:
>> #lang racket
>> 
>> (provide (all-defined-out)
>>         #%datum #%top
>>         (rename-out [new-module-begin #%module-begin]))
>> 
>> (define-syntax-rule
>>  (new-module-begin med-thing ...)
>>  (#%module-begin (display (~a med-thing ... #:separator " "))))
>> 
>> (define hctz25 "Hydrochlorothiazide 25mg")
>> (define simva20 "Simvastatin 20mg")
>> (define pl "pills")
>> (define 1xd "Take 1 pill P.O. 1x/day")
>> (define 1xn "Take 1 pill P.O. 1x at night")
>> (define INSTOMZ "half an hour before breakfast, with a glass of water")
>> (define line "-----------")
>> 
>> And try-it.rkt contains this:
>> #lang s-exp "med.rkt"
>> hctz25 30 pl 1xd
>> simva20 30 pl 1xn
>> 
>> Then running try-it.rkt will produce the output:
>> Hydrochlorothiazide 25mg 30 pills Take 1 pill P.O. 1x/day Simvastatin 20mg
>> 30 pills Take 1 pill P.O. 1x at night
>> 
>> Or if new-module-begin is defined like this instead:
>> (define-syntax-rule
>>  (new-module-begin med-thing ...)
>>  (#%module-begin (provide data) (define data (~a med-thing ... #:separator
>> " "))))
>> 
>> Then doing (require “try-it.rkt”) will import data as the string
>> "Hydrochlorothiazide 25mg 30 pills Take 1 pill P.O. 1x/day Simvastatin 20mg
>> 30 pills Take 1 pill P.O. 1x at night".
>> 
>> 
>> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.racket-lang.org/users/archive/attachments/20140804/3a2530ec/attachment-0001.html>