test-suite/lalr/test-lr-associativity-03.scm

   1 ;;; test-lr-associativity-01.scm --
   2 ;;
   3 ;;Show  how  to use  left  and  right  associativity.  Notice  that  the
   4 ;;terminal M is declared as non-associative; this influences the binding
   5 ;;of values  to the  $n symbols in  the semantic clauses.   The semantic
   6 ;;clause in the rule:
   7 ;;
   8 ;;  (E M E M E)     : (list $1 $2 (list $3 $4 $5))
   9 ;;
  10 ;;looks like it is right-associated,  and it is because we have declared
  11 ;;M as "right:".
  12 ;;
  13
  14 (load "common-test.scm")
  15
  16 (define (doit . tokens)
  17   (let ((parser (lalr-parser
  18                  (expect: 0)
  19                  (N (nonassoc: A)
  20                     (nonassoc: M))
  21                  (E     (N)             : $1
  22                         (E A E)         : (list $1 $2 $3)
  23                         (E A E A E)     : (list (list $1 $2 $3) $4 $5)
  24                         (E M E)         : (list $1 $2 $3)
  25                         (E M E M E)     : (list $1 $2 (list $3 $4 $5))))))
  26     (parser (make-lexer tokens) error-handler)))
  27
  28 ;;; --------------------------------------------------------------------
  29 ;;; Single operator.
  30
  31 (check
  32     (doit (make-lexical-token 'N #f 1))
  33   => 1)
  34
  35 (check
  36     (doit (make-lexical-token 'N #f 1)
  37           (make-lexical-token 'A #f '+)
  38           (make-lexical-token 'N #f 2))
  39   => '(1 + 2))
  40
  41 (check
  42     (doit (make-lexical-token 'N #f 1)
  43           (make-lexical-token 'M #f '*)
  44           (make-lexical-token 'N #f 2))
  45   => '(1 * 2))
  46
  47 ;;; --------------------------------------------------------------------
  48 ;;; Precedence.
  49
  50 (check
  51     (doit (make-lexical-token 'N #f 1)
  52           (make-lexical-token 'A #f '+)
  53           (make-lexical-token 'N #f 2)
  54           (make-lexical-token 'M #f '*)
  55           (make-lexical-token 'N #f 3))
  56   => '(1 + (2 * 3)))
  57
  58 (check
  59     (doit (make-lexical-token 'N #f 1)
  60           (make-lexical-token 'M #f '*)
  61           (make-lexical-token 'N #f 2)
  62           (make-lexical-token 'A #f '+)
  63           (make-lexical-token 'N #f 3))
  64   => '((1 * 2) + 3))
  65
  66 ;;; --------------------------------------------------------------------
  67 ;;; Associativity.
  68
  69 (check
  70     (doit (make-lexical-token 'N #f 1)
  71           (make-lexical-token 'A #f '+)
  72           (make-lexical-token 'N #f 2)
  73           (make-lexical-token 'A #f '+)
  74           (make-lexical-token 'N #f 3))
  75   => '((1 + 2) + 3))
  76
  77 (check
  78     (doit (make-lexical-token 'N #f 1)
  79           (make-lexical-token 'M #f '*)
  80           (make-lexical-token 'N #f 2)
  81           (make-lexical-token 'M #f '*)
  82           (make-lexical-token 'N #f 3))
  83   => '(1 * (2 * 3)))
  84
  85 ;;; end of file