anonymous-gist.rkt

(module+ test
  (require rackunit)

  (let ([ip (open-input-string "2 + 3")])
    (define (ts type tok)
      (token-struct type tok #f #f #f #f #f))
    (define (pt val from to)
      (position-token val (position from #f #f) (position to #f #f)))

    (define (check-lex1 type tok a b)
      (check-equal? (smalltalk/lex ip)
                    (pt (ts type tok) a b)))
    (define (check-lex2 type tok a b c)
      (check-equal? (smalltalk/lex ip)
                    (pt (pt (ts type tok) b c) a b)))

    (check-lex1 'NUM "2" 1 2)
    (check-lex2 'BIN "+" 2 3 4)
    (check-lex2 'NUM "3" 4 5 6)))

(module+ test
  (require rackunit
           racket/match)

  (define (check-lex input . expecteds)
    (let ([ip (open-input-string input)]
          [from2 #f]
          [to2 #f])
      (for ([expected expecteds])
        (match expected
          [`(#f ,n ,m)
           (set! from2 n)
           (set! to2 m)]

          [`(,type ,tok ,from ,to)
           (if from2
               (begin
                 (check-equal? (smalltalk/lex ip)
                               (pt (pt (ts type tok) from to) from2 to2))
                 (set! from2 #f)
                 (set! to2 #f))
               (check-equal? (smalltalk/lex ip)
                             (pt (ts type tok) from to)))]))))

  (define (ws n m)     (list #f n m))
  (define (tk a b c d) (list a b c d))

  (check-lex "2 + 3"
             (tk 'NUM "2" 1 2)
             (ws 2 3)
             (tk 'BIN "+" 3 4)
             (ws 4 5)
             (tk 'NUM "3" 5 6)))