xslt.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 #+sbcl
  33 (declaim (optimize (debug 2)))
  34
  35
  36 (eval-when (:compile-toplevel :load-toplevel :execute)
  37   (defvar *xsl* "http://www.w3.org/1999/XSL/Transform")
  38   (defvar *xml* "http://www.w3.org/XML/1998/namespace")
  39   (defvar *html* "http://www.w3.org/1999/xhtml"))
  40
  41
  42 ;;;; XSLT-ERROR
  43
  44 (define-condition xslt-error (simple-error)
  45   ()
  46   (:documentation "The class of all XSLT errors."))
  47
  48 (define-condition recoverable-xslt-error (xslt-error)
  49   ()
  50   (:documentation "The class of recoverable XSLT errors."))
  51
  52 (defun xslt-error (fmt &rest args)
  53   (error 'xslt-error :format-control fmt :format-arguments args))
  54
  55 ;; Many errors in XSLT are "recoverable", with a specified action that must
  56 ;; be taken if the error isn't raised.  My original plan was to implement
  57 ;; such issues as continuable conditions, so that users are alerted about
  58 ;; portability issues with their stylesheet, but can contiue anyway.
  59 ;;
  60 ;; However, our current test suite driver compares against Saxon results,
  61 ;; and Saxon recovers (nearly) always.  So our coverage of these errors
  62 ;; is very incomplete.
  63 ;;
  64 ;; Re-enable this code once we can check that it's actually being used
  65 ;; everywhere.
  66 (defun xslt-cerror (fmt &rest args)
  67   (declare (ignore fmt args))
  68   #+(or)
  69   (with-simple-restart (recover "recover")
  70     (error 'recoverable-xslt-error
  71            :format-control fmt
  72            :format-arguments args)))
  73
  74 (defvar *debug* nil)
  75
  76 (defmacro handler-case* (form &rest clauses)
  77   ;; like HANDLER-CASE if *DEBUG* is off.  If it's on, don't establish
  78   ;; a handler at all so that we see the real stack traces.  (We could use
  79   ;; HANDLER-BIND here and check at signalling time, but doesn't seem
  80   ;; important.)
  81   (let ((doit (gensym)))
  82     `(flet ((,doit () ,form))
  83        (if *debug*
  84            (,doit)
  85            (handler-case
  86                (,doit)
  87              ,@clauses)))))
  88
  89 (defmacro with-resignalled-errors ((&optional) &body body)
  90   `(invoke-with-resignalled-errors (lambda () ,@body)))
  91
  92 (defun invoke-with-resignalled-errors (fn)
  93   (handler-bind
  94       ((xpath:xpath-error
  95         (lambda (c)
  96           (xslt-error "~A" c)))
  97        (babel-encodings:character-encoding-error
  98         (lambda (c)
  99           (xslt-error "~A" c))))
 100     (funcall fn)))
 101
 102 (defmacro with-forward-compatible-errors (error-form &body body)
 103   `(invoke-with-forward-compatible-errors (lambda () ,@body)
 104                                           (lambda () ,error-form)))
 105
 106 (defun invoke-with-forward-compatible-errors (fn error-fn)
 107   (let ((result))
 108     (tagbody
 109        (handler-bind
 110            ((xpath:xpath-error
 111              (lambda (c)
 112                (declare (ignore c))
 113                (when *forwards-compatible-p*
 114                  (go error)))))
 115          (setf result (funcall fn)))
 116        (go done)
 117      error
 118        (setf result (funcall error-fn))
 119      done)
 120     result))
 121
 122 (defun compile-xpath (xpath &optional env)
 123   (with-resignalled-errors ()
 124     (with-forward-compatible-errors
 125         (lambda (ctx)
 126           (xslt-error "attempt to evaluate an XPath expression with compile-time errors, delayed due to forwards compatible processing: ~A"
 127                       xpath))
 128       (xpath:compile-xpath xpath env))))
 129
 130 (defmacro with-stack-limit ((&optional) &body body)
 131   `(invoke-with-stack-limit (lambda () ,@body)))
 132
 133 (defparameter *without-xslt-current-p* nil)
 134
 135 (defmacro without-xslt-current ((&optional) &body body)
 136   `(invoke-without-xslt-current (lambda () ,@body)))
 137
 138 (defun invoke-without-xslt-current (fn)
 139   (let ((*without-xslt-current-p* t))
 140     (funcall fn)))
 141
 142 ;;; (defun invoke-without-xslt-current (fn)
 143 ;;;   (let ((non-extensions (gethash "" xpath::*extensions*))
 144 ;;;         (xpath::*extensions*
 145 ;;;          ;; hide XSLT extensions
 146 ;;;          (make-hash-table :test #'equal)))
 147 ;;;     (setf (gethash "" xpath::*extensions*) non-extensions)
 148 ;;;     (funcall fn)))
 149
 150
 151 ;;;; Helper functions and macros
 152
 153 (defun check-for-invalid-attributes (valid-names node)
 154   (labels ((check-attribute (a)
 155              (unless
 156                  (let ((uri (stp:namespace-uri a)))
 157                    (or (and (plusp (length uri)) (not (equal uri *xsl*)))
 158                        (find (cons (stp:local-name a) uri)
 159                              valid-names
 160                              :test #'equal)))
 161                (xslt-error "attribute ~A not allowed on ~A"
 162                            (stp:local-name a)
 163                            (stp:local-name node)))))
 164     (stp:map-attributes nil #'check-attribute node)))
 165
 166 (defmacro only-with-attributes ((&rest specs) node &body body)
 167   (let ((valid-names
 168          (mapcar (lambda (entry)
 169                    (if (and (listp entry) (cdr entry))
 170                        (destructuring-bind (name &optional (uri ""))
 171                            (cdr entry)
 172                          (cons name uri))
 173                        (cons (string-downcase
 174                               (princ-to-string
 175                                (symbol-name entry)))
 176                              "")))
 177                  specs))
 178         (%node (gensym)))
 179     `(let ((,%NODE ,node))
 180        (check-for-invalid-attributes ',valid-names ,%NODE)
 181        (stp:with-attributes ,specs ,%NODE
 182          ,@body))))
 183
 184 (defun map-pipe-eagerly (fn pipe)
 185   (xpath::enumerate pipe :key fn :result nil))
 186
 187 (defmacro do-pipe ((var pipe &optional result) &body body)
 188   `(block nil
 189      (map-pipe-eagerly #'(lambda (,var) ,@body) ,pipe)
 190      ,result))
 191
 192
 193 ;;;; XSLT-ENVIRONMENT and XSLT-CONTEXT
 194
 195 (defparameter *initial-namespaces*
 196   '((nil . "")
 197     ("xmlns" . #"http://www.w3.org/2000/xmlns/")
 198     ("xml" . #"http://www.w3.org/XML/1998/namespace")))
 199
 200 (defparameter *namespaces*
 201   *initial-namespaces*)
 202
 203 (defvar *global-variable-declarations*)
 204 (defvar *lexical-variable-declarations*)
 205
 206 (defvar *global-variable-values*)
 207 (defvar *lexical-variable-values*)
 208
 209 (defclass xslt-environment () ())
 210
 211 (defun split-qname (str)
 212   (handler-case
 213       (multiple-value-bind (prefix local-name)
 214           (cxml::split-qname str)
 215         (unless
 216             ;; FIXME: cxml should really offer a function that does
 217             ;; checks for NCName and QName in a sensible way for user code.
 218             ;; cxml::split-qname is tailored to the needs of the parser.
 219             ;;
 220             ;; For now, let's just check the syntax explicitly.
 221             (and (or (null prefix) (xpath::nc-name-p prefix))
 222                  (xpath::nc-name-p local-name))
 223           (xslt-error "not a qname: ~A" str))
 224         (values prefix local-name))
 225     (cxml:well-formedness-violation ()
 226       (xslt-error "not a qname: ~A" str))))
 227
 228 (defun decode-qname (qname env attributep &key allow-unknown-namespace)
 229   (unless qname
 230     (xslt-error "missing name"))
 231   (multiple-value-bind (prefix local-name)
 232       (split-qname qname)
 233     (values local-name
 234             (if (or prefix (not attributep))
 235                 (or (xpath-sys:environment-find-namespace env (or prefix ""))
 236                     (if allow-unknown-namespace
 237                         nil
 238                         (xslt-error "namespace not found: ~A" prefix)))
 239                 "")
 240             prefix)))
 241
 242 (defmethod xpath-sys:environment-find-namespace ((env xslt-environment) prefix)
 243   (or (cdr (assoc prefix *namespaces* :test 'equal))
 244       ;; zzz gross hack.
 245       ;; Change the entire code base to represent "no prefix" as the
 246       ;; empty string consistently.  unparse.lisp has already been changed.
 247       (and (equal prefix "")
 248            (cdr (assoc nil *namespaces* :test 'equal)))
 249       (and (eql prefix nil)
 250            (cdr (assoc "" *namespaces* :test 'equal)))))
 251
 252 (defun find-variable-index (local-name uri table)
 253   (position (cons local-name uri) table :test 'equal))
 254
 255 (defun intern-global-variable (local-name uri)
 256   (or (find-variable-index local-name uri *global-variable-declarations*)
 257       (push-variable local-name uri *global-variable-declarations*)))
 258
 259 (defun push-variable (local-name uri table)
 260   (prog1
 261       (length table)
 262     (vector-push-extend (cons local-name uri) table)))
 263
 264 (defun lexical-variable-value (index &optional (errorp t))
 265   (let ((result (svref *lexical-variable-values* index)))
 266     (when errorp
 267       (assert (not (eq result 'unbound))))
 268     result))
 269
 270 (defun (setf lexical-variable-value) (newval index)
 271   (assert (not (eq newval 'unbound)))
 272   (setf (svref *lexical-variable-values* index) newval))
 273
 274 (defun global-variable-value (index &optional (errorp t))
 275   (let ((result (svref *global-variable-values* index)))
 276     (when errorp
 277       (assert (not (eq result 'unbound))))
 278     result))
 279
 280 (defun (setf global-variable-value) (newval index)
 281   (assert (not (eq newval 'unbound)))
 282   (setf (svref *global-variable-values* index) newval))
 283
 284 (defmethod xpath-sys:environment-find-function
 285     ((env xslt-environment) lname uri)
 286   (or (if (string= uri "")
 287           (or (xpath-sys:find-xpath-function lname *xsl*)
 288               (xpath-sys:find-xpath-function lname uri))
 289           (xpath-sys:find-xpath-function lname uri))
 290       (when *forwards-compatible-p*
 291         (lambda (&rest ignore)
 292           (declare (ignore ignore))
 293           (xslt-error "attempt to call an unknown XPath function (~A); error delayed until run-time due to forwards compatible processing"
 294                       lname)))))
 295
 296 (defmethod xpath-sys:environment-find-variable
 297     ((env xslt-environment) lname uri)
 298   (let ((index
 299          (find-variable-index lname uri *lexical-variable-declarations*)))
 300     (when index
 301       (lambda (ctx)
 302         (declare (ignore ctx))
 303         (svref *lexical-variable-values* index)))))
 304
 305 (defclass lexical-xslt-environment (xslt-environment) ())
 306
 307 (defmethod xpath-sys:environment-find-variable
 308     ((env lexical-xslt-environment) lname uri)
 309   (or (call-next-method)
 310       (let ((index
 311              (find-variable-index lname uri *global-variable-declarations*)))
 312         (when index
 313           (xslt-trace-thunk
 314            (lambda (ctx)
 315              (declare (ignore ctx))
 316              (svref *global-variable-values* index))
 317            "global ~s (uri ~s) = ~s" lname uri :result)))))
 318
 319 (defclass key-environment (xslt-environment) ())
 320
 321 (defmethod xpath-sys:environment-find-variable
 322     ((env key-environment) lname uri)
 323   (declare (ignore lname uri))
 324   (xslt-error "disallowed variable reference"))
 325
 326 (defclass global-variable-environment (xslt-environment)
 327   ((initial-global-variable-thunks
 328     :initarg :initial-global-variable-thunks
 329     :accessor initial-global-variable-thunks)))
 330
 331 (defmethod xpath-sys:environment-find-variable
 332     ((env global-variable-environment) lname uri)
 333   (or (call-next-method)
 334       (gethash (cons lname uri) (initial-global-variable-thunks env))))
 335
 336
 337 ;;;; TOPLEVEL-TEXT-OUTPUT-SINK
 338 ;;;;
 339 ;;;; A sink that serializes only text not contained in any element.
 340
 341 (defmacro with-toplevel-text-output-sink ((var) &body body)
 342   `(invoke-with-toplevel-text-output-sink (lambda (,var) ,@body)))
 343
 344 (defclass toplevel-text-output-sink (sax:default-handler)
 345   ((target :initarg :target :accessor text-output-sink-target)
 346    (depth :initform 0 :accessor textoutput-sink-depth)))
 347
 348 (defmethod sax:start-element ((sink toplevel-text-output-sink)
 349                               namespace-uri local-name qname attributes)
 350   (declare (ignore namespace-uri local-name qname attributes))
 351   (incf (textoutput-sink-depth sink)))
 352
 353 (defmethod sax:characters ((sink toplevel-text-output-sink) data)
 354   (when (zerop (textoutput-sink-depth sink))
 355     (write-string data (text-output-sink-target sink))))
 356
 357 (defmethod sax:unescaped ((sink toplevel-text-output-sink) data)
 358   (sax:characters sink data))
 359
 360 (defmethod sax:end-element ((sink toplevel-text-output-sink)
 361                               namespace-uri local-name qname)
 362   (declare (ignore namespace-uri local-name qname))
 363   (decf (textoutput-sink-depth sink)))
 364
 365 (defun invoke-with-toplevel-text-output-sink (fn)
 366   (with-output-to-string (s)
 367     (funcall fn (make-instance 'toplevel-text-output-sink :target s))))
 368
 369
 370 ;;;; TEXT-FILTER
 371 ;;;;
 372 ;;;; A sink that passes through only text (at any level) and turns to
 373 ;;;; into unescaped characters.
 374
 375 (defclass text-filter (sax:default-handler)
 376   ((target :initarg :target :accessor text-filter-target)))
 377
 378 (defmethod sax:characters ((sink text-filter) data)
 379   (sax:unescaped (text-filter-target sink) data))
 380
 381 (defmethod sax:unescaped ((sink text-filter) data)
 382   (sax:unescaped (text-filter-target sink) data))
 383
 384 (defmethod sax:end-document ((sink text-filter))
 385   (sax:end-document (text-filter-target sink)))
 386
 387 (defun make-text-filter (target)
 388   (make-instance 'text-filter :target target))
 389
 390
 391 ;;;; ESCAPER
 392 ;;;;
 393 ;;;; A sink that recovers from sax:unescaped using sax:characters, as per
 394 ;;;; XSLT 16.4.
 395
 396 (defclass escaper (cxml:broadcast-handler)
 397   ())
 398
 399 (defmethod sax:unescaped ((sink escaper) data)
 400   (sax:characters sink data))
 401
 402 (defun make-escaper (target)
 403   (make-instance 'escaper :handlers (list target)))
 404
 405
 406 ;;;; Names
 407
 408 (defun of-name (local-name)
 409   (stp:of-name local-name *xsl*))
 410
 411 (defun namep (node local-name)
 412   (and (typep node '(or stp:element stp:attribute))
 413        (equal (stp:namespace-uri node) *xsl*)
 414        (equal (stp:local-name node) local-name)))
 415
 416
 417 ;;;; PARSE-STYLESHEET
 418
 419 (defstruct stylesheet
 420   (modes (make-hash-table :test 'equal))
 421   (global-variables (make-empty-declaration-array))
 422   (output-specification (make-output-specification))
 423   (strip-tests nil)
 424   (strip-thunk nil)
 425   (named-templates (make-hash-table :test 'equal))
 426   (attribute-sets (make-hash-table :test 'equal))
 427   (keys (make-hash-table :test 'equal))
 428   (namespace-aliases (make-hash-table :test 'equal))
 429   (decimal-formats (make-hash-table :test 'equal))
 430   (initial-global-variable-thunks (make-hash-table :test 'equal)))
 431
 432 (defstruct mode
 433   (templates nil)
 434   (match-thunk (lambda (ignore) (declare (ignore ignore)) nil)))
 435
 436 (defun find-mode (stylesheet local-name &optional uri)
 437   (gethash (cons local-name uri) (stylesheet-modes stylesheet)))
 438
 439 (defun ensure-mode (stylesheet &optional local-name uri)
 440   (or (find-mode stylesheet local-name uri)
 441       (setf (gethash (cons local-name uri) (stylesheet-modes stylesheet))
 442             (make-mode))))
 443
 444 (defun ensure-mode/qname (stylesheet qname env)
 445   (if qname
 446       (multiple-value-bind (local-name uri)
 447           (decode-qname qname env nil)
 448         (ensure-mode stylesheet local-name uri))
 449       (find-mode stylesheet nil)))
 450
 451 (defun acons-namespaces
 452     (element &optional (bindings *namespaces*) include-redeclared)
 453   (map-namespace-declarations (lambda (prefix uri)
 454                                 (push (cons prefix uri) bindings))
 455                               element
 456                               include-redeclared)
 457   bindings)
 458
 459 (defun find-key (name stylesheet)
 460   (or (gethash name (stylesheet-keys stylesheet))
 461       (xslt-error "unknown key: ~a" name)))
 462
 463 (defun make-key (match use) (cons match use))
 464
 465 (defun key-match (key) (car key))
 466
 467 (defun key-use (key) (cdr key))
 468
 469 (defun add-key (stylesheet name match use)
 470   (push (make-key match use)
 471         (gethash name (stylesheet-keys stylesheet))))
 472
 473 (defvar *excluded-namespaces* (list *xsl*))
 474 (defvar *empty-mode*)
 475 (defvar *default-mode*)
 476
 477 (defvar *xsl-include-stack* nil)
 478
 479 (defun uri-to-pathname (uri)
 480   (cxml::uri-to-pathname (puri:parse-uri uri)))
 481
 482 ;; Why this extra check for literal result element used as stylesheets,
 483 ;; instead of a general check for every literal result element?  Because
 484 ;; Stylesheet__91804 says so.
 485 (defun check-Errors_err035 (literal-result-element)
 486   (let ((*namespaces* (acons-namespaces literal-result-element))
 487         (env (make-instance 'lexical-xslt-environment)))
 488     (stp:with-attributes ((extension-element-prefixes
 489                            "extension-element-prefixes"
 490                            *xsl*))
 491         literal-result-element
 492       (dolist (prefix (words (or extension-element-prefixes "")))
 493         (if (equal prefix "#default")
 494             (setf prefix nil)
 495             (unless (cxml-stp-impl::nc-name-p prefix)
 496               (xslt-error "invalid prefix: ~A" prefix)))
 497         (let ((uri
 498                (or (xpath-sys:environment-find-namespace env prefix)
 499                    (xslt-error "namespace not found: ~A" prefix))))
 500           (when (equal uri (stp:namespace-uri literal-result-element))
 501             (xslt-error "literal result element used as stylesheet, but is ~
 502                          declared as an extension element")))))))
 503
 504 (defun unwrap-2.3 (document)
 505   (let ((literal-result-element (stp:document-element document))
 506         (new-template (stp:make-element "template" *xsl*))
 507         (new-document-element (stp:make-element "stylesheet" *xsl*)))
 508     (check-Errors_err035 literal-result-element)
 509     (setf (stp:attribute-value new-document-element "version")
 510           (or (stp:attribute-value literal-result-element "version" *xsl*)
 511               (xslt-error "not a stylesheet: root element lacks xsl:version")))
 512     (setf (stp:attribute-value new-template "match") "/")
 513     (setf (stp:document-element document) new-document-element)
 514     (stp:append-child new-document-element new-template)
 515     (stp:append-child new-template literal-result-element)
 516     new-document-element))
 517
 518 (defun parse-stylesheet-to-stp (input uri-resolver)
 519   (let* ((d (cxml:parse input (make-text-normalizer (cxml-stp:make-builder))))
 520          (<transform> (stp:document-element d)))
 521     (unless (equal (stp:namespace-uri <transform>) *xsl*)
 522       (setf <transform> (unwrap-2.3 d)))
 523     (strip-stylesheet <transform>)
 524     (unless (and (equal (stp:namespace-uri <transform>) *xsl*)
 525                  (or (equal (stp:local-name <transform>) "transform")
 526                      (equal (stp:local-name <transform>) "stylesheet")))
 527       (xslt-error "not a stylesheet"))
 528     (check-for-invalid-attributes
 529      '(("version" . "")
 530        ("exclude-result-prefixes" . "")
 531        ("extension-element-prefixes" . "")
 532        ("space" . "http://www.w3.org/XML/1998/namespace")
 533        ("id" . ""))
 534      <transform>)
 535     (let ((invalid
 536            (or (stp:find-child-if (of-name "stylesheet") <transform>)
 537                (stp:find-child-if (of-name "transform") <transform>))))
 538       (when invalid
 539         (xslt-error "invalid top-level element ~A" (stp:local-name invalid))))
 540     (dolist (include (stp:filter-children (of-name "include") <transform>))
 541       (let* ((uri (puri:merge-uris (or (stp:attribute-value include "href")
 542                                        (xslt-error "include without href"))
 543                                    (stp:base-uri include)))
 544              (uri (if uri-resolver
 545                       (funcall uri-resolver uri)
 546                       uri))
 547              (str (puri:render-uri uri nil))
 548              (pathname
 549               (handler-case
 550                   (uri-to-pathname uri)
 551                 (cxml:xml-parse-error (c)
 552                   (xslt-error "cannot find included stylesheet ~A: ~A"
 553                               uri c)))))
 554         (with-open-file
 555             (stream pathname
 556                     :element-type '(unsigned-byte 8)
 557                     :if-does-not-exist nil)
 558           (unless stream
 559             (xslt-error "cannot find included stylesheet ~A at ~A"
 560                         uri pathname))
 561           (when (find str *xsl-include-stack* :test #'equal)
 562             (xslt-error "recursive inclusion of ~A" uri))
 563           (let* ((*xsl-include-stack* (cons str *xsl-include-stack*))
 564                  (<transform>2 (parse-stylesheet-to-stp stream uri-resolver)))
 565             (stp:insert-child-after <transform>
 566                                     (stp:copy <transform>2)
 567                                     include)
 568             (stp:detach include)))))
 569     <transform>))
 570
 571 (defvar *instruction-base-uri*) ;misnamed, is also used in other attributes
 572 (defvar *apply-imports-limit*)
 573 (defvar *import-priority*)
 574 (defvar *extension-namespaces*)
 575 (defvar *forwards-compatible-p*)
 576
 577 (defmacro do-toplevel ((var xpath <transform>) &body body)
 578   `(map-toplevel (lambda (,var) ,@body) ,xpath ,<transform>))
 579
 580 (defun map-toplevel (fn xpath <transform>)
 581   (dolist (node (list-toplevel xpath <transform>))
 582     (let ((*namespaces* *initial-namespaces*))
 583       (xpath:do-node-set (ancestor (xpath:evaluate "ancestor::node()" node))
 584         (xpath:with-namespaces (("" #.*xsl*))
 585           (when (xpath:node-matches-p ancestor "stylesheet|transform")
 586             ;; discard namespaces from including stylesheets
 587             (setf *namespaces* *initial-namespaces*)))
 588         (when (xpath-protocol:node-type-p ancestor :element)
 589           (setf *namespaces* (acons-namespaces ancestor *namespaces* t))))
 590       (funcall fn node))))
 591
 592 (defun list-toplevel (xpath <transform>)
 593   (labels ((recurse (sub)
 594              (let ((subsubs
 595                     (xpath-sys:pipe-of
 596                      (xpath:evaluate "transform|stylesheet" sub))))
 597                (xpath::append-pipes
 598                 (xpath-sys:pipe-of (xpath:evaluate xpath sub))
 599                 (xpath::mappend-pipe #'recurse subsubs)))))
 600     (xpath::sort-nodes (recurse <transform>))))
 601
 602 (defmacro with-import-magic ((node env) &body body)
 603   `(invoke-with-import-magic (lambda () ,@body) ,node ,env))
 604
 605 (defun invoke-with-import-magic (fn node env)
 606   (unless (or (namep node "stylesheet") (namep node "transform"))
 607     (setf node (stp:parent node)))
 608   (let ((*excluded-namespaces* (list *xsl*))
 609         (*extension-namespaces* '())
 610         (*forwards-compatible-p*
 611          (not (equal (stp:attribute-value node "version") "1.0"))))
 612     (parse-exclude-result-prefixes! node env)
 613     (parse-extension-element-prefixes! node env)
 614     (funcall fn)))
 615
 616 (defun parse-1-stylesheet (env stylesheet designator uri-resolver)
 617   (let* ((<transform> (parse-stylesheet-to-stp designator uri-resolver))
 618          (instruction-base-uri (stp:base-uri <transform>))
 619          (namespaces (acons-namespaces <transform>))
 620          (apply-imports-limit (1+ *import-priority*))
 621          (continuations '()))
 622     (let ((*namespaces* namespaces))
 623       (invoke-with-import-magic (constantly t) <transform> env))
 624     (do-toplevel (elt "node()" <transform>)
 625       (let ((version (stp:attribute-value (stp:parent elt) "version")))
 626         (cond
 627           ((null version)
 628            (xslt-error "stylesheet lacks version"))
 629           ((equal version "1.0")
 630            (if (typep elt 'stp:element)
 631                (when (or (equal (stp:namespace-uri elt) "")
 632                          (and (equal (stp:namespace-uri elt) *xsl*)
 633                               (not (find (stp:local-name elt)
 634                                          '("key" "template" "output"
 635                                            "strip-space" "preserve-space"
 636                                            "attribute-set" "namespace-alias"
 637                                            "decimal-format" "variable" "param"
 638                                            "import" "include"
 639                                            ;; for include handling:
 640                                            "stylesheet" "transform")
 641                                          :test #'equal))))
 642                  (xslt-error "unknown top-level element ~A" (stp:local-name elt)))
 643                (xslt-error "text at top-level"))))))
 644     (macrolet ((with-specials ((&optional) &body body)
 645                  `(let ((*instruction-base-uri* instruction-base-uri)
 646                         (*namespaces* namespaces)
 647                         (*apply-imports-limit* apply-imports-limit))
 648                     ,@body)))
 649       (with-specials ()
 650         (do-toplevel (import "import" <transform>)
 651           (when (let ((prev (xpath:first-node
 652                              (xpath:evaluate "preceding-sibling::*"
 653                                              import
 654                                              t))))
 655                   (and prev (not (namep prev "import"))))
 656             (xslt-error "import not at beginning of stylesheet"))
 657           (let ((uri (puri:merge-uris (or (stp:attribute-value import "href")
 658                                           (xslt-error "import without href"))
 659                                       (stp:base-uri import))))
 660             (push (parse-imported-stylesheet env stylesheet uri uri-resolver)
 661                   continuations))))
 662       (let ((import-priority
 663              (incf *import-priority*))
 664             (var-cont (prepare-global-variables stylesheet <transform>)))
 665         (parse-namespace-aliases! stylesheet <transform> env)
 666         ;; delay the rest of compilation until we've seen all global
 667         ;; variables:
 668         (lambda ()
 669           (mapc #'funcall (nreverse continuations))
 670           (with-specials ()
 671             (let ((*import-priority* import-priority))
 672               (funcall var-cont)
 673               (parse-keys! stylesheet <transform> env)
 674               (parse-templates! stylesheet <transform> env)
 675               (parse-output! stylesheet <transform> env)
 676               (parse-strip/preserve-space! stylesheet <transform> env)
 677               (parse-attribute-sets! stylesheet <transform> env)
 678               (parse-decimal-formats! stylesheet <transform> env))))))))
 679
 680 (defvar *xsl-import-stack* nil)
 681
 682 (defun parse-imported-stylesheet (env stylesheet uri uri-resolver)
 683   (let* ((uri (if uri-resolver
 684                   (funcall uri-resolver uri)
 685                   uri))
 686          (str (puri:render-uri uri nil))
 687          (pathname
 688           (handler-case
 689               (uri-to-pathname uri)
 690             (cxml:xml-parse-error (c)
 691               (xslt-error "cannot find imported stylesheet ~A: ~A"
 692                           uri c)))))
 693     (with-open-file
 694         (stream pathname
 695                 :element-type '(unsigned-byte 8)
 696                 :if-does-not-exist nil)
 697       (unless stream
 698         (xslt-error "cannot find imported stylesheet ~A at ~A"
 699                     uri pathname))
 700       (when (find str *xsl-import-stack* :test #'equal)
 701         (xslt-error "recursive inclusion of ~A" uri))
 702       (let ((*xsl-import-stack* (cons str *xsl-import-stack*)))
 703         (parse-1-stylesheet env stylesheet stream uri-resolver)))))
 704
 705 (defvar *included-attribute-sets*)
 706
 707 (defun parse-stylesheet (designator &key uri-resolver)
 708   (with-resignalled-errors ()
 709     (xpath:with-namespaces ((nil #.*xsl*))
 710       (let* ((*import-priority* 0)
 711              (xpath:*allow-variables-in-patterns* nil)
 712              (puri:*strict-parse* nil)
 713              (stylesheet (make-stylesheet))
 714              (*stylesheet*
 715               ;; zzz this is for remove-excluded-namespaces only
 716               stylesheet)
 717              (env (make-instance 'lexical-xslt-environment))
 718              (*excluded-namespaces* *excluded-namespaces*)
 719              (*global-variable-declarations* (make-empty-declaration-array))
 720              (*included-attribute-sets* nil))
 721         (ensure-mode stylesheet nil)
 722         (funcall (parse-1-stylesheet env stylesheet designator uri-resolver))
 723         ;; reverse attribute sets:
 724         (let ((table (stylesheet-attribute-sets stylesheet)))
 725           (maphash (lambda (k v)
 726                      (setf (gethash k table) (nreverse v)))
 727                    table))
 728         ;; for Errors_err011
 729         (dolist (sets *included-attribute-sets*)
 730           (loop for (local-name uri nil) in sets do
 731                (find-attribute-set local-name uri stylesheet)))
 732         ;; add default df
 733         (unless (find-decimal-format "" "" stylesheet nil)
 734           (setf (find-decimal-format "" "" stylesheet)
 735                 (make-decimal-format)))
 736         ;; compile a template matcher for each mode:
 737         (loop
 738            for mode being each hash-value in (stylesheet-modes stylesheet)
 739            do
 740              (setf (mode-match-thunk mode)
 741                    (xpath:make-pattern-matcher
 742                     (mapcar #'template-compiled-pattern
 743                             (mode-templates mode)))))
 744         ;; and for the strip tests
 745         (setf (stylesheet-strip-thunk stylesheet)
 746               (let ((patterns (stylesheet-strip-tests stylesheet)))
 747                 (and patterns
 748                      (xpath:make-pattern-matcher
 749                       (mapcar #'strip-test-compiled-pattern patterns)))))
 750         stylesheet))))
 751
 752 (defun parse-attribute-sets! (stylesheet <transform> env)
 753   (do-toplevel (elt "attribute-set" <transform>)
 754     (with-import-magic (elt env)
 755       (push (let* ((sets
 756                     (mapcar (lambda (qname)
 757                               (multiple-value-list (decode-qname qname env nil)))
 758                             (words
 759                              (stp:attribute-value elt "use-attribute-sets"))))
 760                    (instructions
 761                     (stp:map-children
 762                      'list
 763                      (lambda (child)
 764                        (unless
 765                            (and (typep child 'stp:element)
 766                                 (or (and (equal (stp:namespace-uri child) *xsl*)
 767                                          (equal (stp:local-name child)
 768                                                 "attribute"))
 769                                     (find (stp:namespace-uri child)
 770                                           *extension-namespaces*
 771                                           :test 'equal)))
 772                          (xslt-error "non-attribute found in attribute set"))
 773                        (parse-instruction child))
 774                      elt))
 775                    (*lexical-variable-declarations*
 776                     (make-empty-declaration-array))
 777                    (thunk
 778                     (compile-instruction `(progn ,@instructions) env))
 779                    (n-variables (length *lexical-variable-declarations*)))
 780               (push sets *included-attribute-sets*)
 781               (lambda (ctx)
 782                 (with-stack-limit ()
 783                   (loop for (local-name uri nil) in sets do
 784                        (dolist (thunk (find-attribute-set local-name uri))
 785                          (funcall thunk ctx)))
 786                   (let ((*lexical-variable-values*
 787                          (make-variable-value-array n-variables)))
 788                     (funcall thunk ctx)))))
 789             (gethash (multiple-value-bind (local-name uri)
 790                          (decode-qname (or (stp:attribute-value elt "name")
 791                                            (xslt-error "missing name"))
 792                                        env
 793                                        nil)
 794                        (cons local-name uri))
 795                      (stylesheet-attribute-sets stylesheet))))))
 796
 797 (defun parse-namespace-aliases! (stylesheet <transform> env)
 798   (do-toplevel (elt "namespace-alias" <transform>)
 799     (let ((*namespaces* (acons-namespaces elt)))
 800       (only-with-attributes (stylesheet-prefix result-prefix) elt
 801         (unless stylesheet-prefix
 802           (xslt-error "missing stylesheet-prefix in namespace-alias"))
 803         (unless result-prefix
 804           (xslt-error "missing result-prefix in namespace-alias"))
 805         (setf (gethash
 806                (if (equal stylesheet-prefix "#default")
 807                    ""
 808                    (or (xpath-sys:environment-find-namespace
 809                         env
 810                         stylesheet-prefix)
 811                        (xslt-error "stylesheet namespace not found in alias: ~A"
 812                                    stylesheet-prefix)))
 813                (stylesheet-namespace-aliases stylesheet))
 814               (or (xpath-sys:environment-find-namespace
 815                    env
 816                    (if (equal result-prefix "#default")
 817                        ""
 818                        result-prefix))
 819                   (xslt-error "result namespace not found in alias: ~A"
 820                               result-prefix)))))))
 821
 822 (defun parse-decimal-formats! (stylesheet <transform> env)
 823   (do-toplevel (elt "decimal-format" <transform>)
 824     (stp:with-attributes (name
 825                           ;; strings
 826                           infinity
 827                           (nan "NaN")
 828                           ;; characters:
 829                           decimal-separator
 830                           grouping-separator
 831                           zero-digit
 832                           percent
 833                           per-mille
 834                           digit
 835                           pattern-separator
 836                           minus-sign)
 837         elt
 838       (multiple-value-bind (local-name uri)
 839           (if name
 840               (decode-qname name env nil)
 841               (values "" ""))
 842         (let ((current (find-decimal-format local-name uri stylesheet nil))
 843               (new
 844                (let ((seen '()))
 845                  (flet ((chr (key x)
 846                           (when x
 847                             (unless (eql (length x) 1)
 848                               (xslt-error "not a single character: ~A" x))
 849                             (let ((chr (elt x 0)))
 850                               (when (find chr seen)
 851                                 (xslt-error
 852                                  "conflicting decimal format characters: ~A"
 853                                  chr))
 854                               (push chr seen)
 855                               (list key chr))))
 856                         (str (key x)
 857                           (when x
 858                             (list key x))))
 859                    (apply #'make-decimal-format
 860                           (append (str :infinity infinity)
 861                                   (str :nan nan)
 862                                   (chr :decimal-separator decimal-separator)
 863                                   (chr :grouping-separator grouping-separator)
 864                                   (chr :zero-digit zero-digit)
 865                                   (chr :percent percent)
 866                                   (chr :per-mille per-mille)
 867                                   (chr :digit digit)
 868                                   (chr :pattern-separator pattern-separator)
 869                                   (chr :minus-sign minus-sign)))))))
 870           (if current
 871               (unless (decimal-format= current new)
 872                 (xslt-error "decimal format mismatch for ~S" local-name))
 873               (setf (find-decimal-format local-name uri stylesheet) new)))))))
 874
 875 (defun parse-exclude-result-prefixes! (node env)
 876   (stp:with-attributes (exclude-result-prefixes)
 877       node
 878     (dolist (prefix (words (or exclude-result-prefixes "")))
 879       (if (equal prefix "#default")
 880           (setf prefix nil)
 881           (unless (cxml-stp-impl::nc-name-p prefix)
 882             (xslt-error "invalid prefix: ~A" prefix)))
 883       (push (or (xpath-sys:environment-find-namespace env prefix)
 884                 (xslt-error "namespace not found: ~A" prefix))
 885             *excluded-namespaces*))))
 886
 887 (defun parse-extension-element-prefixes! (node env)
 888   (stp:with-attributes (extension-element-prefixes)
 889       node
 890     (dolist (prefix (words (or extension-element-prefixes "")))
 891       (if (equal prefix "#default")
 892           (setf prefix nil)
 893           (unless (cxml-stp-impl::nc-name-p prefix)
 894             (xslt-error "invalid prefix: ~A" prefix)))
 895       (let ((uri
 896              (or (xpath-sys:environment-find-namespace env prefix)
 897                  (xslt-error "namespace not found: ~A" prefix))))
 898         (unless (equal uri *xsl*)
 899           (push uri *extension-namespaces*)
 900           (push uri *excluded-namespaces*))))))
 901
 902 (defun parse-nametest-tokens (str)
 903   (labels ((check (boolean)
 904              (unless boolean
 905                (xslt-error "invalid nametest token")))
 906            (check-null (boolean)
 907              (check (not boolean))))
 908     (cons
 909      :patterns
 910      (mapcar (lambda (name-test)
 911                (destructuring-bind (&optional path &rest junk)
 912                    (cdr (xpath:parse-pattern-expression name-test))
 913                  (check-null junk)
 914                  (check (eq (car path) :path))
 915                  (destructuring-bind (&optional child &rest junk) (cdr path)
 916                    (check-null junk)
 917                    (check (eq (car child) :child))
 918                    (destructuring-bind (nodetest &rest junk) (cdr child)
 919                      (check-null junk)
 920                      (check (or (stringp nodetest)
 921                                 (eq nodetest '*)
 922                                 (and (consp nodetest)
 923                                      (or (eq (car nodetest) :namespace)
 924                                          (eq (car nodetest) :qname)))))))
 925                  path))
 926              (words str)))))
 927
 928 (defstruct strip-test
 929   compiled-pattern
 930   priority
 931   position
 932   value)
 933
 934 (defun parse-strip/preserve-space! (stylesheet <transform> env)
 935   (let ((i 0))
 936     (do-toplevel (elt "strip-space|preserve-space" <transform>)
 937       (let ((*namespaces* (acons-namespaces elt))
 938             (value
 939              (if (equal (stp:local-name elt) "strip-space")
 940                  :strip
 941                  :preserve)))
 942         (dolist (expression
 943                   (cdr (parse-nametest-tokens
 944                         (stp:attribute-value elt "elements"))))
 945           (let* ((compiled-pattern
 946                   (car (without-xslt-current ()
 947                          (xpath:compute-patterns
 948                           `(:patterns ,expression)
 949                           *import-priority*
 950                           "will set below"
 951                           env))))
 952                  (strip-test
 953                   (make-strip-test :compiled-pattern compiled-pattern
 954                                    :priority (expression-priority expression)
 955                                    :position i
 956                                    :value value)))
 957             (setf (xpath:pattern-value compiled-pattern) strip-test)
 958             (push strip-test (stylesheet-strip-tests stylesheet)))))
 959       (incf i))))
 960
 961 (defstruct (output-specification
 962              (:conc-name "OUTPUT-"))
 963   method
 964   indent
 965   omit-xml-declaration
 966   encoding
 967   doctype-system
 968   doctype-public
 969   cdata-section-matchers
 970   standalone-p
 971   media-type)
 972
 973 (defun parse-output! (stylesheet <transform> env)
 974   (dolist (<output> (list-toplevel "output" <transform>))
 975     (let ((spec (stylesheet-output-specification stylesheet)))
 976       (only-with-attributes (version
 977                              method
 978                              indent
 979                              encoding
 980                              media-type
 981                              doctype-system
 982                              doctype-public
 983                              omit-xml-declaration
 984                              standalone
 985                              cdata-section-elements)
 986           <output>
 987         (declare (ignore version))
 988         (when method
 989           (multiple-value-bind  (local-name uri)
 990               (decode-qname method env t)
 991             (setf (output-method spec)
 992                   (if (plusp (length uri))
 993                       nil
 994                       (cond
 995                         ((equalp local-name "HTML") :html)
 996                         ((equalp local-name "TEXT") :text)
 997                         ((equalp local-name "XML") :xml)
 998                         (t
 999                          (xslt-error "invalid output method: ~A" method)))))))
1000         (when indent
1001           (setf (output-indent spec) indent))
1002         (when encoding
1003           (setf (output-encoding spec) encoding))
1004         (when doctype-system
1005           (setf (output-doctype-system spec) doctype-system))
1006         (when doctype-public
1007           (setf (output-doctype-public spec) doctype-public))
1008         (when omit-xml-declaration
1009           (setf (output-omit-xml-declaration spec) omit-xml-declaration))
1010         (when cdata-section-elements
1011           (dolist (qname (words cdata-section-elements))
1012             (decode-qname qname env nil) ;check the syntax
1013             (push (xpath:make-pattern-matcher* qname env)
1014                   (output-cdata-section-matchers spec))))
1015         (when standalone
1016           (setf (output-standalone-p spec)
1017                 (boolean-or-error standalone)))
1018         (when media-type
1019           (setf (output-media-type spec) media-type))))))
1020
1021 (defun make-empty-declaration-array ()
1022   (make-array 1 :fill-pointer 0 :adjustable t))
1023
1024 (defun make-variable-value-array (n-lexical-variables)
1025   (make-array n-lexical-variables :initial-element 'unbound))
1026
1027 (defun compile-global-variable (<variable> env) ;; also for <param>
1028   (stp:with-attributes (name select) <variable>
1029     (when (and select (stp:list-children <variable>))
1030       (xslt-error "variable with select and body"))
1031     (let* ((*lexical-variable-declarations* (make-empty-declaration-array))
1032            (inner (cond
1033                     (select
1034                      (compile-xpath select env))
1035                     ((stp:list-children <variable>)
1036                      (let* ((inner-sexpr `(progn ,@(parse-body <variable>)))
1037                             (inner-thunk (compile-instruction inner-sexpr env)))
1038                        (lambda (ctx)
1039                          (apply-to-result-tree-fragment ctx inner-thunk))))
1040                     (t
1041                      (lambda (ctx)
1042                        (declare (ignore ctx))
1043                        ""))))
1044            (n-lexical-variables (length *lexical-variable-declarations*)))
1045       (xslt-trace-thunk
1046        (lambda (ctx)
1047          (let* ((*lexical-variable-values*
1048                  (make-variable-value-array n-lexical-variables)))
1049            (funcall inner ctx)))
1050        "global ~s (~s) = ~s" name select :result))))
1051
1052 (defstruct (variable-chain
1053              (:constructor make-variable-chain)
1054              (:conc-name "VARIABLE-CHAIN-"))
1055   definitions
1056   index
1057   local-name
1058   thunk
1059   uri)
1060
1061 (defstruct (import-variable
1062              (:constructor make-variable)
1063              (:conc-name "VARIABLE-"))
1064   value-thunk
1065   value-thunk-setter
1066   param-p)
1067
1068 (defun parse-global-variable! (stylesheet <variable> global-env)
1069   (let* ((*namespaces* (acons-namespaces <variable>))
1070          (instruction-base-uri (stp:base-uri <variable>))
1071          (*instruction-base-uri* instruction-base-uri)
1072          (*excluded-namespaces* (list *xsl*))
1073          (*extension-namespaces* '())
1074          (qname (stp:attribute-value <variable> "name")))
1075     (with-import-magic (<variable> global-env)
1076       (unless qname
1077         (xslt-error "name missing in ~A" (stp:local-name <variable>)))
1078       (multiple-value-bind (local-name uri)
1079           (decode-qname qname global-env nil)
1080         ;; For the normal compilation environment of templates, install it
1081         ;; into *GLOBAL-VARIABLE-DECLARATIONS*:
1082         (let ((index (intern-global-variable local-name uri)))
1083           ;; For the evaluation of a global variable itself, build a thunk
1084           ;; that lazily resolves other variables, stored into
1085           ;; INITIAL-GLOBAL-VARIABLE-THUNKS:
1086           (let* ((value-thunk :unknown)
1087                  (sgv (stylesheet-global-variables stylesheet))
1088                  (chain
1089                   (if (< index (length sgv))
1090                       (elt sgv index)
1091                       (make-variable-chain
1092                        :index index
1093                        :local-name local-name
1094                        :uri uri)))
1095                  (next (car (variable-chain-definitions chain)))
1096                  (global-variable-thunk
1097                   (lambda (ctx)
1098                     (let ((v (global-variable-value index nil)))
1099                       (cond
1100                         ((eq v 'seen)
1101                          (unless next
1102                            (xslt-error "no next definition for: ~A"
1103                                        local-name))
1104                          (funcall (variable-value-thunk next) ctx))
1105                         ((eq v 'unbound)
1106                          (setf (global-variable-value index) 'seen)
1107                          (setf (global-variable-value index)
1108                                (funcall value-thunk ctx)))
1109                         (t
1110                          v)))))
1111                  (excluded-namespaces *excluded-namespaces*)
1112                  (extension-namespaces *extension-namespaces*)
1113                  (variable
1114                   (make-variable :param-p (namep <variable> "param")))
1115                  (forwards-compatible-p *forwards-compatible-p*)
1116                  (value-thunk-setter
1117                   (lambda ()
1118                     (let* ((*instruction-base-uri* instruction-base-uri)
1119                            (*excluded-namespaces* excluded-namespaces)
1120                            (*extension-namespaces* extension-namespaces)
1121                            (*forwards-compatible-p* forwards-compatible-p)
1122                            (fn
1123                             (compile-global-variable <variable> global-env)))
1124                       (setf value-thunk fn)
1125                       (setf (variable-value-thunk variable) fn)))))
1126             (setf (variable-value-thunk-setter variable)
1127                   value-thunk-setter)
1128             (setf (gethash (cons local-name uri)
1129                            (initial-global-variable-thunks global-env))
1130                   global-variable-thunk)
1131             (setf (variable-chain-thunk chain) global-variable-thunk)
1132             (push variable (variable-chain-definitions chain))
1133             chain))))))
1134
1135 (defun parse-keys! (stylesheet <transform> env)
1136   (xpath:with-namespaces ((nil #.*xsl*))
1137     (do-toplevel (<key> "key" <transform>)
1138       (with-import-magic (<key> env)
1139         (let ((*instruction-base-uri* (stp:base-uri <key>)))
1140           (only-with-attributes (name match use) <key>
1141             (unless name (xslt-error "key name attribute not specified"))
1142             (unless match (xslt-error "key match attribute not specified"))
1143             (unless use (xslt-error "key use attribute not specified"))
1144             (multiple-value-bind (local-name uri)
1145                 (decode-qname name env nil)
1146               (add-key stylesheet
1147                        (cons local-name uri)
1148                        (compile-xpath `(xpath:xpath ,(parse-key-pattern match))
1149                                       env)
1150                        (compile-xpath use
1151                                       (make-instance 'key-environment))))))))))
1152
1153 (defun prepare-global-variables (stylesheet <transform>)
1154   (xpath:with-namespaces ((nil #.*xsl*))
1155     (let* ((igvt (stylesheet-initial-global-variable-thunks stylesheet))
1156            (global-env (make-instance 'global-variable-environment
1157                                       :initial-global-variable-thunks igvt))
1158            (chains '()))
1159       (do-toplevel (<variable> "variable|param" <transform>)
1160         (let ((chain
1161                (parse-global-variable! stylesheet <variable> global-env)))
1162           (xslt-trace "parsing global variable ~s (uri ~s)"
1163                       (variable-chain-local-name chain)
1164                       (variable-chain-uri chain))
1165           (when (find chain
1166                       chains
1167                       :test (lambda (a b)
1168                               (and (equal (variable-chain-local-name a)
1169                                           (variable-chain-local-name b))
1170                                    (equal (variable-chain-uri a)
1171                                           (variable-chain-uri b)))))
1172             (xslt-error "duplicate definition for global variable ~A"
1173                         (variable-chain-local-name chain)))
1174           (push chain chains)))
1175       (setf chains (nreverse chains))
1176       (let ((table (stylesheet-global-variables stylesheet))
1177             (newlen (length *global-variable-declarations*)))
1178         (adjust-array table newlen :fill-pointer newlen)
1179         (dolist (chain chains)
1180           (setf (elt table (variable-chain-index chain)) chain)))
1181       (lambda ()
1182         ;; now that the global environment knows about all variables, run the
1183         ;; thunk setters to perform their compilation
1184         (mapc (lambda (chain)
1185                 (dolist (var (variable-chain-definitions chain))
1186                   (funcall (variable-value-thunk-setter var))))
1187               chains)))))
1188
1189 (defun parse-templates! (stylesheet <transform> env)
1190   (let ((i 0))
1191     (do-toplevel (<template> "template" <transform>)
1192       (let ((*namespaces* (acons-namespaces <template>))
1193             (*instruction-base-uri* (stp:base-uri <template>)))
1194         (with-import-magic (<template> env)
1195           (dolist (template (compile-template <template> env i))
1196             (let ((name (template-name template)))
1197               (if name
1198                   (let* ((table (stylesheet-named-templates stylesheet))
1199                          (head (car (gethash name table))))
1200                     (when (and head (eql (template-import-priority head)
1201                                          (template-import-priority template)))
1202                       ;; fixme: is this supposed to be a run-time error?
1203                       (xslt-error "conflicting templates for ~A" name))
1204                     (push template (gethash name table)))
1205                   (let ((mode (ensure-mode/qname stylesheet
1206                                                  (template-mode-qname template)
1207                                                  env)))
1208                     (setf (template-mode template) mode)
1209                     (push template (mode-templates mode))))))))
1210       (incf i))))
1211
1212
1213 ;;;; APPLY-STYLESHEET
1214
1215 (defvar *stylesheet*)
1216
1217 (deftype xml-designator () '(or runes:xstream runes:rod array stream pathname))
1218
1219 (defun unalias-uri (uri)
1220   (let ((result
1221          (gethash uri (stylesheet-namespace-aliases *stylesheet*)
1222                   uri)))
1223     (check-type result string)
1224     result))
1225
1226 (defstruct (parameter
1227              (:constructor make-parameter (value local-name &optional uri)))
1228   (uri "")
1229   local-name
1230   value)
1231
1232 (defun find-parameter-value (local-name uri parameters)
1233   (dolist (p parameters)
1234     (when (and (equal (parameter-local-name p) local-name)
1235                (equal (parameter-uri p) uri))
1236       (return (parameter-value p)))))
1237
1238 (defvar *uri-resolver*)
1239
1240 (defun parse-allowing-microsoft-bom (pathname handler)
1241   (with-open-file (s pathname :element-type '(unsigned-byte 8))
1242     (unless (and (eql (read-byte s nil) #xef)
1243                  (eql (read-byte s nil) #xbb)
1244                  (eql (read-byte s nil) #xbf))
1245       (file-position s 0))
1246     (cxml:parse s handler)))
1247
1248 (defvar *documents*)
1249
1250 (defun %document (uri-string base-uri)
1251   (let* ((absolute-uri
1252           (puri:merge-uris uri-string (or base-uri "")))
1253          (resolved-uri
1254           (if *uri-resolver*
1255               (funcall *uri-resolver* absolute-uri)
1256               absolute-uri))
1257          (pathname
1258           (handler-case
1259               (uri-to-pathname resolved-uri)
1260             (cxml:xml-parse-error (c)
1261               (xslt-error "cannot find referenced document ~A: ~A"
1262                           resolved-uri c))))
1263          (xpath-root-node
1264           (or (gethash pathname *documents*)
1265               (setf (gethash pathname *documents*)
1266                     (make-whitespace-stripper
1267                      (handler-case
1268                          (parse-allowing-microsoft-bom pathname
1269                                                        (stp:make-builder))
1270                        ((or file-error cxml:xml-parse-error) (c)
1271                          (xslt-error "cannot parse referenced document ~A: ~A"
1272                                      pathname c)))
1273                      (stylesheet-strip-thunk *stylesheet*))))))
1274     (when (puri:uri-fragment absolute-uri)
1275       (xslt-error "use of fragment identifiers in document() not supported"))
1276     xpath-root-node))
1277
1278 (xpath-sys:define-extension xslt *xsl*)
1279
1280 (defun document-base-uri (node)
1281   (xpath-protocol:base-uri
1282    (cond
1283      ((xpath-protocol:node-type-p node :document)
1284       (xpath::find-in-pipe-if
1285        (lambda (x)
1286          (xpath-protocol:node-type-p x :element))
1287        (xpath-protocol:child-pipe node)))
1288      ((xpath-protocol:node-type-p node :element)
1289       node)
1290      (t
1291       (xpath-protocol:parent-node node)))))
1292
1293 (xpath-sys:define-xpath-function/lazy
1294     xslt :document
1295     (object &optional node-set)
1296   (let ((instruction-base-uri *instruction-base-uri*))
1297     (lambda (ctx)
1298       (let* ((object (funcall object ctx))
1299              (node-set (and node-set (funcall node-set ctx)))
1300              (base-uri
1301               (if node-set
1302                   (document-base-uri (xpath::textually-first-node node-set))
1303                   instruction-base-uri)))
1304         (xpath-sys:make-node-set
1305          (if (xpath:node-set-p object)
1306              (xpath:map-node-set->list
1307               (lambda (node)
1308                 (%document (xpath:string-value node)
1309                            (if node-set
1310                                base-uri
1311                                (document-base-uri node))))
1312               object)
1313              (list (%document (xpath:string-value object) base-uri))))))))
1314
1315 ;; FIXME: the point of keys is that we are meant to optimize this
1316 ;; by building a table mapping nodes to values for each key.
1317 ;; We should run over all matching nodes and store them in such a table
1318 ;; when seeing their document for the first time.
1319 (xpath-sys:define-xpath-function/lazy xslt :key (name object)
1320   (let ((namespaces *namespaces*))
1321     (lambda (ctx)
1322       (let* ((qname (xpath:string-value (funcall name ctx)))
1323              (object (funcall object ctx))
1324              (expanded-name
1325               (multiple-value-bind (local-name uri)
1326                   (decode-qname/runtime qname namespaces nil)
1327                 (cons local-name uri)))
1328              (key-conses (find-key expanded-name *stylesheet*)))
1329         (xpath-sys:make-node-set
1330          (xpath::mappend-pipe
1331           (lambda (key)
1332             (labels ((get-by-key (value)
1333                        (let ((value (xpath:string-value value)))
1334                          (xpath::filter-pipe
1335                           #'(lambda (node)
1336                               (let ((uses
1337                                      (xpath:evaluate-compiled (key-use key)
1338                                                               node)))
1339                                 (if (xpath:node-set-p uses)
1340                                     (xpath::find-in-pipe
1341                                      value
1342                                      (xpath-sys:pipe-of uses)
1343                                      :key #'xpath:string-value
1344                                      :test #'equal)
1345                                     (equal value (xpath:string-value uses)))))
1346                           (xpath-sys:pipe-of
1347                            (xpath:node-set-value
1348                             (xpath:evaluate-compiled (key-match key) ctx)))))))
1349               (xpath::sort-pipe
1350                (if (xpath:node-set-p object)
1351                    (xpath::mappend-pipe #'get-by-key
1352                                         (xpath-sys:pipe-of object))
1353                    (get-by-key object)))))
1354           key-conses))))))
1355
1356 ;; FIXME: add alias mechanism for XPath extensions in order to avoid duplication
1357
1358 (xpath-sys:define-xpath-function/lazy xslt :current ()
1359   (when *without-xslt-current-p*
1360     (xslt-error "current() not allowed here"))
1361   #'(lambda (ctx)
1362       (xpath-sys:make-node-set
1363        (xpath-sys:make-pipe
1364         (xpath:context-starting-node ctx)
1365         nil))))
1366
1367 (xpath-sys:define-xpath-function/lazy xslt :unparsed-entity-uri (name)
1368   #'(lambda (ctx)
1369       (or (xpath-protocol:unparsed-entity-uri (xpath:context-node ctx)
1370                                               (funcall name ctx))
1371           "")))
1372
1373 (defun %get-node-id (node)
1374   (when (xpath:node-set-p node)
1375     (setf node (xpath::textually-first-node node)))
1376   (when node
1377     (let ((id (xpath-sys:get-node-id node))
1378           (highest-base-uri
1379            (loop
1380               for parent = node then next
1381               for next = (xpath-protocol:parent-node parent)
1382               for this-base-uri = (xpath-protocol:base-uri parent)
1383               for highest-base-uri = (if (plusp (length this-base-uri))
1384                                          this-base-uri
1385                                          highest-base-uri)
1386               while next
1387               finally (return highest-base-uri))))
1388       ;; FIXME: Now that we intern documents, we could use a short ID for
1389       ;; the document instead of the base URI.
1390       (nreverse (concatenate 'string highest-base-uri "//" id)))))
1391
1392 (xpath-sys:define-xpath-function/lazy xslt :generate-id (&optional node-set-thunk)
1393   (if node-set-thunk
1394       #'(lambda (ctx)
1395           (%get-node-id (xpath:node-set-value (funcall node-set-thunk ctx))))
1396       #'(lambda (ctx)
1397           (%get-node-id (xpath:context-node ctx)))))
1398
1399 (declaim (special *available-instructions*))
1400
1401 (xpath-sys:define-xpath-function/lazy xslt :element-available (qname)
1402   (let ((namespaces *namespaces*))
1403     #'(lambda (ctx)
1404         (let ((qname (funcall qname ctx)))
1405           (multiple-value-bind (local-name uri)
1406               (decode-qname/runtime qname namespaces nil)
1407             (and (equal uri *xsl*)
1408                  (gethash local-name *available-instructions*)
1409                  t))))))
1410
1411 (xpath-sys:define-xpath-function/lazy xslt :function-available (qname)
1412   (let ((namespaces *namespaces*))
1413     #'(lambda (ctx)
1414         (let ((qname (funcall qname ctx)))
1415           (multiple-value-bind (local-name uri)
1416               (decode-qname/runtime qname namespaces nil)
1417             (and (zerop (length uri))
1418                  (or (xpath-sys:find-xpath-function local-name *xsl*)
1419                      (xpath-sys:find-xpath-function local-name uri))
1420                  t))))))
1421
1422 (xpath-sys:define-xpath-function/lazy xslt :system-property (qname)
1423   (let ((namespaces *namespaces*))
1424     (lambda (ctx)
1425       (let ((qname (xpath:string-value (funcall qname ctx))))
1426         (multiple-value-bind (local-name uri)
1427             (decode-qname/runtime qname namespaces nil)
1428           (if (equal uri *xsl*)
1429               (cond
1430                 ((equal local-name "version")
1431                  "1")
1432                 ((equal local-name "vendor")
1433                  "Xuriella")
1434                 ((equal local-name "vendor-url")
1435                  "http://repo.or.cz/w/xuriella.git")
1436                 (t
1437                  ""))
1438               ""))))))
1439
1440 ;; FIXME: should there be separate uri-resolver arguments for stylesheet
1441 ;; and data?
1442 (defun apply-stylesheet
1443     (stylesheet source-designator
1444      &key output parameters uri-resolver navigator)
1445   (when (typep stylesheet 'xml-designator)
1446     (setf stylesheet
1447           (handler-bind
1448               ((cxml:xml-parse-error
1449                 (lambda (c)
1450                   (xslt-error "cannot parse stylesheet: ~A" c))))
1451             (parse-stylesheet stylesheet :uri-resolver uri-resolver))))
1452   (with-resignalled-errors ()
1453     (invoke-with-output-sink
1454      (lambda ()
1455        (let* ((*documents* (make-hash-table :test 'equal))
1456               (xpath:*navigator* (or navigator :default-navigator))
1457               (puri:*strict-parse* nil)
1458               (*stylesheet* stylesheet)
1459               (*empty-mode* (make-mode))
1460               (*default-mode* (find-mode stylesheet nil))
1461               (global-variable-chains
1462                (stylesheet-global-variables stylesheet))
1463               (*global-variable-values*
1464                (make-variable-value-array (length global-variable-chains)))
1465               (*uri-resolver* uri-resolver)
1466               (source-document
1467                (if (typep source-designator 'xml-designator)
1468                    (cxml:parse source-designator (stp:make-builder))
1469                    source-designator))
1470               (xpath-root-node
1471                (make-whitespace-stripper
1472                 source-document
1473                 (stylesheet-strip-thunk stylesheet)))
1474               (ctx (xpath:make-context xpath-root-node)))
1475          (when (pathnamep source-designator)
1476            (setf (gethash source-designator *documents*) xpath-root-node))
1477          (map nil
1478               (lambda (chain)
1479                 (let ((head (car (variable-chain-definitions chain))))
1480                   (when (variable-param-p head)
1481                     (let ((value
1482                            (find-parameter-value
1483                             (variable-chain-local-name chain)
1484                             (variable-chain-uri chain)
1485                             parameters)))
1486                       (when value
1487                         (setf (global-variable-value
1488                                (variable-chain-index chain))
1489                               value))))))
1490               global-variable-chains)
1491          (map nil
1492               (lambda (chain)
1493                 (funcall (variable-chain-thunk chain) ctx))
1494               global-variable-chains)
1495          ;; zzz we wouldn't have to mask float traps here if we used the
1496          ;; XPath API properly.  Unfortunately I've been using FUNCALL
1497          ;; everywhere instead of EVALUATE, so let's paper over that
1498          ;; at a central place to be sure:
1499          (xpath::with-float-traps-masked ()
1500            (apply-templates ctx :mode *default-mode*))))
1501      (stylesheet-output-specification stylesheet)
1502      output)))
1503
1504 (defun find-attribute-set (local-name uri &optional (stylesheet *stylesheet*))
1505   (or (gethash (cons local-name uri) (stylesheet-attribute-sets stylesheet))
1506       (xslt-error "no such attribute set: ~A/~A" local-name uri)))
1507
1508 (defun apply-templates/list (list &key param-bindings sort-predicate mode)
1509   (when sort-predicate
1510     (setf list
1511           (mapcar #'xpath:context-node
1512                   (stable-sort (contextify-node-list list)
1513                                sort-predicate))))
1514   (let* ((n (length list))
1515          (s/d (lambda () n)))
1516     (loop
1517        for i from 1
1518        for child in list
1519        do
1520          (apply-templates (xpath:make-context child s/d i)
1521                           :param-bindings param-bindings
1522                           :mode mode))))
1523
1524 (defvar *stack-limit* 200)
1525
1526 (defun invoke-with-stack-limit (fn)
1527   (let ((*stack-limit* (1- *stack-limit*)))
1528     (unless (plusp *stack-limit*)
1529       (xslt-error "*stack-limit* reached; stack overflow"))
1530     (funcall fn)))
1531
1532 (defun invoke-template (ctx template param-bindings)
1533   (let ((*lexical-variable-values*
1534          (make-variable-value-array (template-n-variables template))))
1535     (with-stack-limit ()
1536       (loop
1537          for (name-cons value) in param-bindings
1538          for (nil index nil) = (find name-cons
1539                                      (template-params template)
1540                                      :test #'equal
1541                                      :key #'car)
1542          do
1543            (when index
1544              (setf (lexical-variable-value index) value)))
1545       (funcall (template-body template) ctx))))
1546
1547 (defun apply-default-templates (ctx mode)
1548   (let ((node (xpath:context-node ctx)))
1549     (cond
1550       ((or (xpath-protocol:node-type-p node :processing-instruction)
1551            (xpath-protocol:node-type-p node :comment)))
1552       ((or (xpath-protocol:node-type-p node :text)
1553            (xpath-protocol:node-type-p node :attribute))
1554        (write-text (xpath-protocol:node-text node)))
1555       (t
1556        (apply-templates/list
1557         (xpath::force
1558          (xpath-protocol:child-pipe node))
1559         :mode mode)))))
1560
1561 (defvar *apply-imports*)
1562
1563 (defun apply-applicable-templates (ctx templates param-bindings finally)
1564   (labels ((apply-imports (&optional actual-param-bindings)
1565              (if templates
1566                  (let* ((this (pop templates))
1567                         (low (template-apply-imports-limit this))
1568                         (high (template-import-priority this)))
1569                    (setf templates
1570                          (remove-if-not
1571                           (lambda (x)
1572                             (<= low (template-import-priority x) high))
1573                           templates))
1574                    (invoke-template ctx this actual-param-bindings))
1575                  (funcall finally))))
1576     (let ((*apply-imports* #'apply-imports))
1577       (apply-imports param-bindings))))
1578
1579 (defun apply-templates (ctx &key param-bindings mode)
1580   (apply-applicable-templates ctx
1581                               (find-templates ctx (or mode *default-mode*))
1582                               param-bindings
1583                               (lambda ()
1584                                 (apply-default-templates ctx mode))))
1585
1586 (defun call-template (ctx name &optional param-bindings)
1587   (apply-applicable-templates ctx
1588                               (find-named-templates name)
1589                               param-bindings
1590                               (lambda ()
1591                                 (xslt-error "cannot find named template: ~s"
1592                                             name))))
1593
1594 (defun find-templates (ctx mode)
1595   (let* ((matching-candidates
1596           (xpath:matching-values (mode-match-thunk mode)
1597                                  (xpath:context-node ctx)))
1598          (npriorities
1599           (if matching-candidates
1600               (1+ (reduce #'max
1601                           matching-candidates
1602                           :key #'template-import-priority))
1603               0))
1604          (priority-groups (make-array npriorities :initial-element nil)))
1605     (dolist (template matching-candidates)
1606       (push template
1607             (elt priority-groups (template-import-priority template))))
1608     (loop
1609        for i from (1- npriorities) downto 0
1610        for group = (elt priority-groups i)
1611        for template = (maximize #'template< group)
1612        when template
1613        collect template)))
1614
1615 (defun find-named-templates (name)
1616   (gethash name (stylesheet-named-templates *stylesheet*)))
1617
1618 (defun template< (a b)                  ;assuming same import priority
1619   (let ((p (template-priority a))
1620         (q (template-priority b)))
1621     (cond
1622       ((< p q) t)
1623       ((> p q) nil)
1624       (t
1625        (xslt-cerror "conflicting templates:~_~A,~_~A"
1626                     (template-match-expression a)
1627                     (template-match-expression b))
1628        (< (template-position a) (template-position b))))))
1629
1630 (defun maximize (< things)
1631   (when things
1632     (let ((max (car things)))
1633       (dolist (other (cdr things))
1634         (when (funcall < max other)
1635           (setf max other)))
1636       max)))
1637
1638 (defun invoke-with-output-sink (fn output-spec output)
1639   (etypecase output
1640     (pathname
1641      (with-open-file (s output
1642                         :direction :output
1643                         :element-type '(unsigned-byte 8)
1644                         :if-exists :rename-and-delete)
1645        (invoke-with-output-sink fn output-spec s)))
1646     ((or stream null)
1647      (invoke-with-output-sink fn
1648                               output-spec
1649                               (make-output-sink output-spec output)))
1650     ((or hax:abstract-handler sax:abstract-handler)
1651      (with-xml-output output
1652        (when (typep output '(or combi-sink auto-detect-sink))
1653          (sax:start-dtd output
1654                         :autodetect-me-please
1655                         (output-doctype-public output-spec)
1656                         (output-doctype-system output-spec)))
1657        (funcall fn)))))
1658
1659 (defun make-output-sink (output-spec stream)
1660   (let* ((ystream
1661           (if stream
1662               (let ((et (stream-element-type stream)))
1663                 (cond
1664                   ((or (null et) (subtypep et '(unsigned-byte 8)))
1665                    (runes:make-octet-stream-ystream stream))
1666                   ((subtypep et 'character)
1667                    (runes:make-character-stream-ystream stream))))
1668               (runes:make-rod-ystream)))
1669          (omit-xml-declaration-p
1670           (boolean-or-error (output-omit-xml-declaration output-spec)))
1671          (sink-encoding (or (output-encoding output-spec) "UTF-8"))
1672          (sax-target
1673           (progn
1674             (setf (runes:ystream-encoding ystream)
1675                   (cxml::find-output-encoding sink-encoding))
1676             (make-instance 'cxml::sink
1677                            :ystream ystream
1678                            :omit-xml-declaration-p omit-xml-declaration-p
1679                            :encoding sink-encoding))))
1680     (flet ((make-combi-sink ()
1681              (make-instance 'combi-sink
1682                             :hax-target (make-instance 'chtml::sink
1683                                                        :ystream ystream)
1684                             :sax-target sax-target
1685                             :media-type (output-media-type output-spec)
1686                             :encoding sink-encoding)))
1687       (let ((method-key (output-method output-spec)))
1688         (cond
1689           ((and (eq method-key :html)
1690                 (null (output-doctype-system output-spec))
1691                 (null (output-doctype-public output-spec)))
1692            (make-combi-sink))
1693           ((eq method-key :text)
1694            (make-text-filter sax-target))
1695           ((and (eq method-key :xml)
1696                 (null (output-doctype-system output-spec)))
1697            sax-target)
1698           (t
1699            (make-auto-detect-sink (make-combi-sink) method-key)))))))
1700
1701 (defstruct template
1702   match-expression
1703   compiled-pattern
1704   name
1705   import-priority
1706   apply-imports-limit
1707   priority
1708   position
1709   mode
1710   mode-qname
1711   params
1712   body
1713   n-variables)
1714
1715 (defun expression-priority (form)
1716   (let ((step (second form)))
1717     (if (and (null (cddr form))
1718              (listp step)
1719              (member (car step) '(:child :attribute))
1720              (null (cddr step)))
1721         (let ((name (second step)))
1722           (cond
1723             ((or (stringp name)
1724                  (and (consp name)
1725                       (or (eq (car name) :qname)
1726                           (eq (car name) :processing-instruction))))
1727              0.0)
1728             ((and (consp name)
1729                   (or (eq (car name) :namespace)
1730                       (eq (car name) '*)))
1731              -0.25)
1732             (t
1733              -0.5)))
1734         0.5)))
1735
1736 (defun parse-key-pattern (str)
1737   (with-resignalled-errors ()
1738     (with-forward-compatible-errors
1739         (xpath:parse-xpath "compile-time-error()") ;hack
1740       (let ((parsed
1741              (mapcar #'(lambda (item)
1742                          `(:path (:root :node)
1743                                  (:descendant-or-self :node)
1744                                  ,@(cdr item)))
1745                      (cdr (xpath::parse-pattern-expression str)))))
1746         (if (null (rest parsed))
1747             (first parsed)
1748             `(:union ,@parsed))))))
1749
1750 (defun compile-value-thunk (value env)
1751   (if (and (listp value) (eq (car value) 'progn))
1752       (let ((inner-thunk (compile-instruction value env)))
1753         (lambda (ctx)
1754           (apply-to-result-tree-fragment ctx inner-thunk)))
1755       (compile-xpath value env)))
1756
1757 (defun compile-var-binding (name value env)
1758   (multiple-value-bind (local-name uri)
1759       (decode-qname name env nil)
1760     (let ((thunk (xslt-trace-thunk
1761                   (compile-value-thunk value env)
1762                   "local variable ~s = ~s" name :result)))
1763       (list (cons local-name uri)
1764             (push-variable local-name
1765                            uri
1766                            *lexical-variable-declarations*)
1767             thunk))))
1768
1769 (defun compile-var-bindings (forms env)
1770   (loop
1771      for (name value) in forms
1772      collect (compile-var-binding name value env)))
1773
1774 (defmacro sometimes-with-attributes ((&rest attrs) node &body body)
1775   (let ((x (gensym)))
1776     `(let ((,x ,node))
1777        (if *forwards-compatible-p*
1778            (stp:with-attributes (,@attrs) ,x ,@body)
1779            (only-with-attributes (,@attrs) ,x ,@body)))))
1780
1781 (defun compile-template (<template> env position)
1782   (sometimes-with-attributes (match name priority mode) <template>
1783     (unless (or name match)
1784       (xslt-error "missing match in template"))
1785     (multiple-value-bind (params body-pos)
1786         (loop
1787           for i from 0
1788           for child in (stp:list-children <template>)
1789           while (namep child "param")
1790           collect (parse-param child) into params
1791           finally (return (values params i)))
1792       (let* ((*lexical-variable-declarations* (make-empty-declaration-array))
1793              (param-bindings (compile-var-bindings params env))
1794              (body (parse-body <template> body-pos (mapcar #'car params)))
1795              (body-thunk (compile-instruction `(progn ,@body) env))
1796              (outer-body-thunk
1797               (xslt-trace-thunk
1798                #'(lambda (ctx)
1799                    (unwind-protect
1800                        (progn
1801                          ;; set params that weren't initialized by apply-templates
1802                          (loop for (name index param-thunk) in param-bindings
1803                                when (eq (lexical-variable-value index nil) 'unbound)
1804                                  do (setf (lexical-variable-value index)
1805                                           (funcall param-thunk ctx)))
1806                          (funcall body-thunk ctx))))
1807                "template: match = ~s name = ~s" match name))
1808              (n-variables (length *lexical-variable-declarations*)))
1809         (append
1810          (when name
1811            (multiple-value-bind (local-name uri)
1812                (decode-qname name env nil)
1813              (list
1814               (make-template :name (cons local-name uri)
1815                              :import-priority *import-priority*
1816                              :apply-imports-limit *apply-imports-limit*
1817                              :params param-bindings
1818                              :body outer-body-thunk
1819                              :n-variables n-variables))))
1820          (when match
1821            (mapcar (lambda (expression)
1822                      (let* ((compiled-pattern
1823                              (xslt-trace-thunk
1824                               (car (without-xslt-current ()
1825                                      (xpath:compute-patterns
1826                                       `(:patterns ,expression)
1827                                       42
1828                                       :dummy
1829                                       env)))
1830                               "match-thunk for template (match ~s): ~s --> ~s"
1831                               match expression :result))
1832                             (p (if priority
1833                                    (xpath::parse-xnum priority)
1834                                    (expression-priority expression)))
1835                             (p
1836                              (progn
1837                                (unless (and (numberp p)
1838                                             (not (xpath::inf-p p))
1839                                             (not (xpath::nan-p p)))
1840                                  (xslt-error "failed to parse priority"))
1841                                (float p 1.0d0)))
1842                             (template
1843                              (make-template :match-expression expression
1844                                             :compiled-pattern compiled-pattern
1845                                             :import-priority *import-priority*
1846                                             :apply-imports-limit *apply-imports-limit*
1847                                             :priority p
1848                                             :position position
1849                                             :mode-qname mode
1850                                             :params param-bindings
1851                                             :body outer-body-thunk
1852                                             :n-variables n-variables)))
1853                        (setf (xpath:pattern-value compiled-pattern)
1854                              template)
1855                        template))
1856                    (cdr (xpath:parse-pattern-expression match)))))))))
1857 #+(or)
1858 (xuriella::parse-stylesheet #p"/home/david/src/lisp/xuriella/test.xsl")