test-suite/lalr/test-lr-error-recovery-02.scm

   1 ;;; test-lr-error-recovery-02.scm --
   2 ;;
   3 ;;Test error  recovery policy when the synchronisation  terminal has the
   4 ;;same category of the lookahead that raises the error.
   5 ;;
   6
   7 (load "common-test.scm")
   8
   9 (define (doit . tokens)
  10   (let ((parser (lalr-parser (expect: 0)
  11                              (A B C)
  12                              (alphas (alpha)            : $1
  13                                      (alphas alpha)     : $2)
  14                              (alpha (A B)       : (list $1 $2)
  15                                     (C)         : $1
  16                                     (error C)   : 'error-form))))
  17     (parser (make-lexer tokens) error-handler)))
  18
  19 ;;; --------------------------------------------------------------------
  20 ;;; No error, just grammar tests.
  21
  22 (check
  23     (doit (make-lexical-token 'A #f 1)
  24           (make-lexical-token 'B #f 2))
  25   => '(1 2))
  26
  27 (check
  28     (doit (make-lexical-token 'C #f 3))
  29   => '3)
  30
  31 ;;; --------------------------------------------------------------------
  32 ;;; Successful error recovery.
  33
  34 (check
  35     ;;Error, recovery, end-of-input.
  36     (let ((r (doit (make-lexical-token 'A #f 1)
  37                    (make-lexical-token 'C #f 3))))
  38       (cons r *error*))
  39   => '(error-form (error-handler "Syntax error: unexpected token : " . C)))
  40
  41 (check
  42     ;;Error, recovery, correct parse of "A B".
  43     (let ((r (doit (make-lexical-token 'A #f 1)
  44                    (make-lexical-token 'C #f 3)
  45                    (make-lexical-token 'A #f 1)
  46                    (make-lexical-token 'B #f 2))))
  47       (cons r *error*))
  48   => '((1 2)
  49        (error-handler "Syntax error: unexpected token : " . C)))
  50
  51 ;;; end of file