ice-9/syncase.scm

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  42 \f
  43
  44 (define-module (ice-9 syncase)
  45   :use-module (ice-9 debug))
  46
  47 \f
  48
  49 (define-public sc-macro
  50   (procedure->memoizing-macro
  51     (lambda (exp env)
  52       (sc-expand exp))))
  53
  54 ;;; Exported variables
  55
  56 (define-public sc-expand #f)
  57 (define-public sc-expand3 #f)
  58 (define-public install-global-transformer #f)
  59 (define-public syntax-dispatch #f)
  60 (define-public syntax-error #f)
  61
  62 (define-public bound-identifier=? #f)
  63 (define-public datum->syntax-object #f)
  64 (define-public define-syntax sc-macro)
  65 (define-public eval-when sc-macro)
  66 (define-public fluid-let-syntax sc-macro)
  67 (define-public free-identifier=? #f)
  68 (define-public generate-temporaries #f)
  69 (define-public identifier? #f)
  70 (define-public identifier-syntax sc-macro)
  71 (define-public let-syntax sc-macro)
  72 (define-public letrec-syntax sc-macro)
  73 (define-public syntax sc-macro)
  74 (define-public syntax-case sc-macro)
  75 (define-public syntax-object->datum #f)
  76 (define-public syntax-rules sc-macro)
  77 (define-public with-syntax sc-macro)
  78 (define-public include sc-macro)
  79
  80 (define primitive-syntax '(quote lambda letrec if set! begin define or
  81                               and let let* cond do quasiquote unquote
  82                               unquote-splicing case))
  83
  84 (for-each (lambda (symbol)
  85             (set-symbol-property! symbol 'primitive-syntax #t))
  86           primitive-syntax)
  87
  88 ;;; Hooks needed by the syntax-case macro package
  89
  90 (define-public (void) *unspecified*)
  91
  92 (define andmap
  93   (lambda (f first . rest)
  94     (or (null? first)
  95         (if (null? rest)
  96             (let andmap ((first first))
  97               (let ((x (car first)) (first (cdr first)))
  98                 (if (null? first)
  99                     (f x)
 100                     (and (f x) (andmap first)))))
 101             (let andmap ((first first) (rest rest))
 102               (let ((x (car first))
 103                     (xr (map car rest))
 104                     (first (cdr first))
 105                     (rest (map cdr rest)))
 106                 (if (null? first)
 107                     (apply f (cons x xr))
 108                     (and (apply f (cons x xr)) (andmap first rest)))))))))
 109
 110 (define (error who format-string why what)
 111   (start-stack 'syncase-stack
 112                (scm-error 'misc-error
 113                           who
 114                           "~A ~S"
 115                           (list why what)
 116                           '())))
 117
 118 (define the-syncase-module (current-module))
 119
 120 (define (putprop symbol key binding)
 121   (let* ((m (current-module))
 122          (v (or (module-variable m symbol)
 123                 (module-make-local-var! m symbol))))
 124     (if (symbol-property symbol 'primitive-syntax)
 125         (if (eq? (current-module) the-syncase-module)
 126             (set-object-property! (module-variable the-root-module symbol)
 127                                   key
 128                                   binding))
 129         (variable-set! v sc-macro))
 130     (set-object-property! v key binding)))
 131
 132 (define (getprop symbol key)
 133   (let* ((m (current-module))
 134          (v (module-variable m symbol)))
 135     (and v (or (object-property v key)
 136                (let ((root-v (module-local-variable the-root-module symbol)))
 137                  (and (equal? root-v v)
 138                       (object-property root-v key)))))))
 139
 140 (define generated-symbols (make-weak-key-hash-table 1019))
 141
 142 ;;; Utilities
 143
 144 (define (psyncomp)
 145   (system "mv -f psyntax.pp psyntax.pp~")
 146   (let ((in (open-input-file "psyntax.ss"))
 147         (out (open-output-file "psyntax.pp")))
 148     (let loop ((x (read in)))
 149       (if (eof-object? x)
 150           (begin
 151             (close-port out)
 152             (close-port in))
 153           (begin
 154             (write (sc-expand3 x 'c '(compile load eval)) out)
 155             (newline out)
 156             (loop (read in)))))))
 157
 158 ;;; Load the preprocessed code
 159
 160 (let ((old-debug #f)
 161       (old-read #f))
 162   (dynamic-wind (lambda ()
 163                   (set! old-debug (debug-options))
 164                   (set! old-read (read-options)))
 165                 (lambda ()
 166                   (debug-disable 'debug 'procnames)
 167                   (read-disable 'positions)
 168                   (load-from-path "ice-9/psyntax.pp"))
 169                 (lambda ()
 170                   (debug-options old-debug)
 171                   (read-options old-read))))
 172
 173
 174 ;;; The following lines are necessary only if we start making changes
 175 ;; (use-syntax sc-expand)
 176 ;; (load-from-path "ice-9/psyntax.ss")
 177
 178 (define internal-eval (nested-ref the-scm-module '(app modules guile eval)))
 179
 180 (define-public (eval x environment)
 181   (internal-eval (if (and (pair? x)
 182                           (equal? (car x) "noexpand"))
 183                      (cadr x)
 184                      (sc-expand x))
 185                  environment))
 186
 187 ;;; Hack to make syncase macros work in the slib module
 188 (let ((m (nested-ref the-root-module '(app modules ice-9 slib))))
 189   (if m
 190       (set-object-property! (module-local-variable m 'define)
 191                             '*sc-expander*
 192                             '(define))))
 193
 194 (define-public syncase sc-expand)