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Paste # 48179
2019-04-23 14:31:40

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Embed:

#lang racket

(define (map f xs)
    (if (null? xs)
        null
    (cons (f (car xs)) (map f (cdr xs))))
    
(define xs ' (1 2 3 4))
(define f (lambda (x) (+ x 1)))
map (lambda (x) (+ x 1)) xs)

(define (filter f xs)
    (if (null? xs)
        null
        (if (f car xs))
        `   cons (car xs) (filter f (cdr xs)))
            (filter f (cdr xs)))))

=>

prog:17:32: read: unexpected `)'
  context...:
   /home/pasterack/racket68/collects/syntax/module-reader.rkt:186:17: body
   /home/pasterack/racket68/collects/syntax/module-reader.rkt:183:2: wrap-internal
   /home/pasterack/racket68/collects/racket/../syntax/module-reader.rkt:65:9: lang:read-syntax
   /home/pasterack/racket68/share/pkgs/scribble-lib/scribble/private/manual-code.rkt:112:0: get-tokens
   /home/pasterack/racket68/share/pkgs/scribble-lib/scribble/private/manual-code.rkt:56:0: typeset-code15
   /home/pasterack/pasterack/tmp/48179/48179code.scrbl: [running body]
   loop
   ...cket/cmdline.rkt:179:51
   /home/pasterack/racket68/share/pkgs/scribble-lib/scribble/run.rkt: [running body]