parser.lisp

   1 ;;; -*- show-trailing-whitespace: t; indent-tabs-mode: nil -*-
   2
   3 ;;; Copyright (c) 2007,2008 David Lichteblau, Ivan Shvedunov.
   4 ;;; All rights reserved.
   5
   6 ;;; Redistribution and use in source and binary forms, with or without
   7 ;;; modification, are permitted provided that the following conditions
   8 ;;; are met:
   9 ;;;
  10 ;;;   * Redistributions of source code must retain the above copyright
  11 ;;;     notice, this list of conditions and the following disclaimer.
  12 ;;;
  13 ;;;   * Redistributions in binary form must reproduce the above
  14 ;;;     copyright notice, this list of conditions and the following
  15 ;;;     disclaimer in the documentation and/or other materials
  16 ;;;     provided with the distribution.
  17 ;;;
  18 ;;; THIS SOFTWARE IS PROVIDED BY THE AUTHOR 'AS IS' AND ANY EXPRESSED
  19 ;;; OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20 ;;; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21 ;;; ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  22 ;;; DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23 ;;; DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  24 ;;; GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  25 ;;; INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  26 ;;; WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  27 ;;; NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  28 ;;; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 (in-package :xuriella)
  31
  32 (defun map-namespace-declarations (fn element &optional include-redeclared)
  33   (let ((parent (stp:parent element)))
  34     (maphash (lambda (prefix uri)
  35                (unless (and (not include-redeclared)
  36                             (typep parent 'stp:element)
  37                             (equal (stp:find-namespace prefix parent) uri))
  38                  (funcall fn prefix uri)))
  39              (cxml-stp-impl::collect-local-namespaces element))))
  40
  41 (defun maybe-wrap-namespaces (child exprs)
  42   (if (typep child 'stp:element)
  43       (let ((bindings '())
  44             (excluded-uris '()))
  45         (map-namespace-declarations (lambda (prefix uri)
  46                                       (push (list prefix uri) bindings))
  47                                     child)
  48         (stp:with-attributes ((erp "exclude-result-prefixes" *xsl*))
  49             child
  50           (dolist (prefix (words (or erp "")))
  51             (when (equal prefix "#default")
  52               (setf prefix nil))
  53             (push (or (stp:find-namespace prefix child)
  54                       (xslt-error "namespace not found: ~A" prefix))
  55                   excluded-uris)))
  56         (if (or bindings excluded-uris)
  57             `((xsl:with-namespaces ,bindings
  58                 (xsl:with-excluded-namespaces ,excluded-uris
  59                   ,@exprs)))
  60             exprs))
  61       exprs))
  62
  63 (defun parse-body (node &optional (start 0) (param-names '()))
  64   (let ((n (stp:count-children-if #'identity node)))
  65     (labels ((recurse (i)
  66                (when (< i n)
  67                  (let ((child (stp:nth-child i node)))
  68                    (if (namep child "variable")
  69                        (maybe-wrap-namespaces
  70                         child
  71                         (only-with-attributes (name select) child
  72                           (when (and select (stp:list-children child))
  73                             (xslt-error "variable with select and body"))
  74                           `((let ((,name ,(or select
  75                                               `(progn ,@(parse-body child)))))
  76                               (xsl:with-duplicates-check (,name)
  77                                 ,@(recurse (1+ i)))))))
  78                        (append (maybe-wrap-namespaces
  79                                 child
  80                                 (list (parse-instruction child)))
  81                                (recurse (1+ i))))))))
  82       (let ((result (recurse start)))
  83         (if param-names
  84             `((xsl:with-duplicates-check (,@param-names)
  85                 ,@result))
  86             result)))))
  87
  88 (defun parse-param (node)
  89   ;; FIXME: empty body?
  90   (only-with-attributes (name select) node
  91     (unless name
  92       (xslt-error "name not specified for parameter"))
  93     (when (and select (stp:list-children node))
  94       (xslt-error "param with select and body"))
  95     (list name
  96           (or select
  97               `(progn ,@(parse-body node))))))
  98
  99 (defun parse-instruction (node)
 100   (typecase node
 101     (stp:element
 102      (let ((expr
 103             (cond
 104               ((equal (stp:namespace-uri node) *xsl*)
 105                (let ((sym (find-symbol (stp:local-name node) :xuriella)))
 106                  (cond
 107                    (sym
 108                     (parse-instruction/xsl-element sym node))
 109                    (*forwards-compatible-p*
 110                     (parse-fallback-children node))
 111                    (t
 112                     (xslt-error "undefined instruction: ~A"
 113                                 (stp:local-name node))))))
 114               ((find (stp:namespace-uri node)
 115                      *extension-namespaces*
 116                      :test #'equal)
 117                (let ((extension (find-extension-element
 118                                  (stp:local-name node)
 119                                  (stp:namespace-uri node))))
 120                  (if extension
 121                      (funcall (extension-element-parser extension) node)
 122                      (parse-fallback-children node))))
 123               (t
 124                (parse-instruction/literal-element node))))
 125            (parent (stp:parent node)))
 126        (if (and (equal (stp:base-uri node) (stp:base-uri parent))
 127                 (equal (stp:namespace-uri parent) *xsl*)
 128                 (find-symbol (stp:local-name parent) :xuriella))
 129            expr
 130            `(xsl:with-base-uri ,(stp:base-uri node)
 131               ,expr))))
 132     (stp:text
 133      `(xsl:text ,(stp:data node)))))
 134
 135 (defun parse-instruction/literal-element (node)
 136   (let ((extensions '()))
 137     (stp:with-attributes ((eep "extension-element-prefixes" *xsl*))
 138         node
 139       (dolist (prefix (words (or eep "")))
 140         (when (equal prefix "#default")
 141           (setf prefix nil))
 142         (push (or (stp:find-namespace prefix node)
 143                   (xslt-error "namespace not found: ~A" prefix))
 144               extensions)))
 145     (if (find (stp:namespace-uri node) extensions :test #'equal)
 146         ;; oops, this isn't a literal result element after all
 147         (parse-fallback-children node)
 148         (let ((le
 149                `(xsl:literal-element
 150                     (,(stp:local-name node)
 151                       ,(stp:namespace-uri node)
 152                       ,(stp:namespace-prefix node))
 153                   (xsl:use-attribute-sets
 154                    ,(stp:attribute-value node "use-attribute-sets" *xsl*))
 155                   ,@(loop
 156                        for a in (stp:list-attributes node)
 157                        for xslp = (equal (stp:namespace-uri a) *xsl*)
 158                        when xslp
 159                        do (unless (find (stp:local-name a)
 160                                         '("version"
 161                                           "extension-element-prefixes"
 162                                           "exclude-result-prefixes"
 163                                           "use-attribute-sets")
 164                                         :test #'equal)
 165                             (xslt-error
 166                              "unknown attribute on literal result element: ~A"
 167                              (stp:local-name a)))
 168                        else
 169                        collect `(xsl:literal-attribute
 170                                     (,(stp:local-name a)
 171                                       ,(stp:namespace-uri a)
 172                                       ,(stp:namespace-prefix a))
 173                                   ,(stp:value a)))
 174                   ,@ (let ((*extension-namespaces*
 175                             (append extensions *extension-namespaces*)))
 176                        (parse-body node))))
 177               (version (stp:attribute-value node "version" *xsl*)))
 178           (when extensions
 179             (setf le
 180                   `(xsl:with-extension-namespaces ,extensions
 181                      (xsl:with-excluded-namespaces ,extensions
 182                        ,le))))
 183           (when version
 184             (setf le
 185                   `(xsl:with-version ,version
 186                      ,le)))
 187           le))))
 188
 189 (defun parse-fallback-children (node)
 190   (let ((fallbacks
 191          (loop
 192             for fallback in (stp:filter-children (of-name "fallback") node)
 193             do (only-with-attributes () fallback)
 194             append (parse-body fallback))))
 195     (if fallbacks
 196         `(progn ,@fallbacks)
 197         `(xsl:terminate
 198            (xsl:text
 199             "no fallback children in unknown element using forwards compatible processing")))))
 200
 201 (defmacro define-instruction-parser (name (node-var) &body body)
 202   `(progn
 203      (setf (gethash ,(symbol-name name) *builtin-instructions*) t)
 204      (defmethod parse-instruction/xsl-element
 205          ((.name. (eql ',name)) ,node-var)
 206        (declare (ignore .name.))
 207        ,@body)))
 208
 209 (define-instruction-parser |fallback| (node)
 210   (only-with-attributes () node
 211     '(progn)))
 212
 213 (define-instruction-parser |apply-templates| (node)
 214   (only-with-attributes (select mode) node
 215     (multiple-value-bind (decls rest)
 216         (loop
 217            for i from 0
 218            for cons on (stp:filter-children
 219                         (lambda (node)
 220                           (or (typep node 'stp:element)
 221                               (xslt-error "non-element in apply-templates")))
 222                         node)
 223            for (child . nil) = cons
 224            while (namep child "sort")
 225            collect (parse-sort child) into decls
 226            finally (return (values decls cons)))
 227       `(xsl:apply-templates
 228            (:select ,select :mode ,mode)
 229          (declare ,@decls)
 230          ,@(mapcar (lambda (clause)
 231                      (unless (namep clause "with-param")
 232                        (xslt-error "undefined instruction: ~A"
 233                                    (stp:local-name clause)))
 234                      (parse-param clause))
 235                    rest)))))
 236
 237 (define-instruction-parser |apply-imports| (node)
 238   (only-with-attributes () node)
 239   (assert-no-body node)
 240   `(xsl:apply-imports))
 241
 242 (define-instruction-parser |call-template| (node)
 243   (only-with-attributes (name) node
 244       `(xsl:call-template
 245         ,name ,@(stp:map-children 'list
 246                                   (lambda (clause)
 247                                     (if (namep clause "with-param")
 248                                         (parse-param clause)
 249                                         (xslt-error "undefined instruction: ~A"
 250                                                     (stp:local-name clause))))
 251                                   node))))
 252
 253 (define-instruction-parser |if| (node)
 254   (only-with-attributes (test) node
 255     `(when ,test
 256        ,@(parse-body node))))
 257
 258 (define-instruction-parser |choose| (node)
 259   (let ((whenp nil))
 260     (prog1
 261         (only-with-attributes () node
 262           `(cond
 263              ,@(stp:map-children 'list
 264                                  (lambda (clause)
 265                                    (cond
 266                                      ((namep clause "when")
 267                                       (setf whenp t)
 268                                       (only-with-attributes (test) clause
 269                                         `(,test
 270                                           ,@(parse-body clause))))
 271                                      ((namep clause "otherwise")
 272                                       `(t ,@(parse-body clause)))
 273                                      (t
 274                                       (xslt-error "invalid <choose> clause: ~A"
 275                                                   (stp:local-name clause)))))
 276                                  node)))
 277       (unless whenp
 278         (xslt-error "<choose> without <when>")))))
 279
 280 (define-instruction-parser |element| (node)
 281   (only-with-attributes (name namespace use-attribute-sets) node
 282     `(xsl:element (,name :namespace ,namespace)
 283        (xsl:use-attribute-sets ,use-attribute-sets)
 284        ,@(parse-body node))))
 285
 286 (define-instruction-parser |attribute| (node)
 287   (only-with-attributes (name namespace) node
 288     `(xsl:attribute (,name :namespace ,namespace)
 289        ,@(parse-body node))))
 290
 291 (defun boolean-or-error (str)
 292   (cond
 293     ((equal str "yes")
 294      t)
 295     ((or (null str) (equal str "no"))
 296      nil)
 297     (t
 298      (xslt-error "not a boolean: ~A" str))))
 299
 300 (define-instruction-parser |text| (node)
 301   (only-with-attributes (select disable-output-escaping) node
 302     (when (xpath:evaluate "boolean(*)" node)
 303       (xslt-error "non-text found in xsl:text"))
 304     (if (boolean-or-error disable-output-escaping)
 305         `(xsl:unescaped-text ,(stp:string-value node))
 306         `(xsl:text ,(stp:string-value node)))))
 307
 308 (define-instruction-parser |comment| (node)
 309   (only-with-attributes () node
 310     `(xsl:comment ,@(parse-body node))))
 311
 312 (define-instruction-parser |processing-instruction| (node)
 313   (only-with-attributes (name) node
 314     `(xsl:processing-instruction ,name
 315        ,@(parse-body node))))
 316
 317 (defun assert-no-body (node)
 318   (when (stp:list-children node)
 319     (xslt-error "no child nodes expected in ~A" (stp:local-name node))))
 320
 321 (define-instruction-parser |value-of| (node)
 322   (only-with-attributes (select disable-output-escaping) node
 323     (assert-no-body node)
 324     (if (boolean-or-error disable-output-escaping)
 325         `(xsl:unescaped-value-of ,select)
 326         `(xsl:value-of ,select))))
 327
 328 (define-instruction-parser |copy-of| (node)
 329   (only-with-attributes (select) node
 330     (assert-no-body node)
 331     `(xsl:copy-of ,select)))
 332
 333 (define-instruction-parser |copy| (node)
 334   (only-with-attributes (use-attribute-sets) node
 335     `(xsl:copy
 336       (xsl:use-attribute-sets ,use-attribute-sets)
 337       ,@(parse-body node))))
 338
 339 (define-instruction-parser |variable| (node)
 340   (xslt-error "unhandled xsl:variable"))
 341
 342 (define-instruction-parser |for-each| (node)
 343   (only-with-attributes (select) node
 344     (multiple-value-bind (decls body-position)
 345         (loop
 346            for i from 0
 347            for child in (stp:list-children node)
 348            while (namep child "sort")
 349            collect (parse-sort child) into decls
 350            finally (return (values decls i)))
 351       `(xsl:for-each ,select
 352          (declare ,@decls)
 353          ,@(parse-body node body-position)))))
 354
 355 (defun parse-sort (node)
 356   (only-with-attributes (select lang data-type order case-order) node
 357     (assert-no-body node)
 358     `(sort :select ,select
 359            :lang ,lang
 360            :data-type ,data-type
 361            :order ,order
 362            :case-order ,case-order)))
 363
 364 (define-instruction-parser |message| (node)
 365   (only-with-attributes (terminate) node
 366     (if (boolean-or-error terminate)
 367         `(xsl:terminate ,@(parse-body node))
 368         `(xsl:message ,@(parse-body node)))))
 369
 370 (define-instruction-parser |number| (node)
 371   (only-with-attributes (level count from value format lang letter-value
 372                                    grouping-separator grouping-size)
 373       node
 374     (assert-no-body node)
 375     `(xsl:number :level ,level
 376                  :count ,count
 377                  :from ,from
 378                  :value ,value
 379                  :format ,format
 380                  :lang ,lang
 381                  :letter-value ,letter-value
 382                  :grouping-separator ,grouping-separator
 383                  :grouping-size ,grouping-size)))