mdw@git.distorted.org.uk Git - sod/blob - src/module-parse.lisp

   1 ;;; -*-lisp-*-
   2 ;;;
   3 ;;; Top-level parser for module syntax
   4 ;;;
   5 ;;; (c) 2010 Straylight/Edgeware
   6 ;;;
   7
   8 ;;;----- Licensing notice ---------------------------------------------------
   9 ;;;
  10 ;;; This file is part of the Sensble Object Design, an object system for C.
  11 ;;;
  12 ;;; SOD is free software; you can redistribute it and/or modify
  13 ;;; it under the terms of the GNU General Public License as published by
  14 ;;; the Free Software Foundation; either version 2 of the License, or
  15 ;;; (at your option) any later version.
  16 ;;;
  17 ;;; SOD is distributed in the hope that it will be useful,
  18 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;;; GNU General Public License for more details.
  21 ;;;
  22 ;;; You should have received a copy of the GNU General Public License
  23 ;;; along with SOD; if not, write to the Free Software Foundation,
  24 ;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 (in-package #:sod)
  27
  28 ;;;--------------------------------------------------------------------------
  29 ;;; Toplevel syntax.
  30
  31 (export 'module)
  32
  33 ;;; Type names.
  34
  35 (define-pluggable-parser module typename (scanner)
  36   ;; `typename' ID ( `,' ID )* `;'
  37
  38   (with-parser-context (token-scanner-context :scanner scanner)
  39     (parse (and "typename"
  40                 (skip-many (:min 1)
  41                   (seq ((id :id))
  42                     (if (gethash id *module-type-map*)
  43                         (cerror* "Type `~A' already defined" id)
  44                         (add-to-module *module*
  45                                        (make-instance 'type-item
  46                                                       :name id))))
  47                   #\,)
  48                 #\;))))
  49
  50 ;;; Fragments.
  51
  52 (define-pluggable-parser module code (scanner)
  53   ;; `code' ID `:' ID [ CONSTRAINTS ] `{' C-FRAGMENT `}'
  54
  55   (with-parser-context (token-scanner-context :scanner scanner)
  56     (parse (seq ("code"
  57                  (reason :id)
  58                  #\:
  59                  (name :id)
  60                  (constraints (? (seq (#\[
  61                                        (constraints (list (:min 1)
  62                                                       (list (:min 1) :id)
  63                                                       #\,))
  64                                        #\])
  65                                    constraints)))
  66                  (fragment (parse-delimited-fragment scanner #\{ #\})))
  67              (add-to-module *module* (make-instance 'code-fragment-item
  68                                                     :fragment fragment
  69                                                     :constraints constraints
  70                                                     :reason reason
  71                                                     :name name))))))
  72
  73 ;;; External files.
  74
  75 (defun read-module (pathname &key (truename (truename pathname)) location)
  76   "Parse the file at PATHNAME as a module, returning it.
  77
  78    This is the main entry point for parsing module files.  You may well know
  79    the file's TRUENAME already (e.g., because `probe-file' dropped it into
  80    your lap) so you can avoid repeating the search by providing it.
  81
  82    The LOCATION is the thing which wanted the module imported -- usually a
  83    `file-location' object, though it might be anything other than `t' which
  84    can be printed in the event of circular imports."
  85
  86   (define-module (pathname :location location :truename truename)
  87     (with-open-file (f-stream pathname :direction :input)
  88       (let* ((*readtable* (copy-readtable))
  89              (char-scanner (make-instance 'charbuf-scanner
  90                                           :stream f-stream))
  91              (scanner (make-instance 'sod-token-scanner
  92                                      :char-scanner char-scanner)))
  93         (with-default-error-location (scanner)
  94           (with-parser-context (token-scanner-context :scanner scanner)
  95             (parse (skip-many () (plug module scanner)))))))))
  96
  97 (define-pluggable-parser module test (scanner)
  98   ;; `demo' STRING `;'
  99
 100   (with-parser-context (token-scanner-context :scanner scanner)
 101     (parse (seq ("demo" (string :string) #\;)
 102              (format t ";; DEMO ~S~%" string)))))
 103
 104 (define-pluggable-parser module file (scanner)
 105   ;; `import' STRING `;'
 106   ;; `load' STRING `;'
 107
 108   (flet ((common (name type what thunk)
 109            (find-file scanner
 110                       (merge-pathnames name
 111                                        (make-pathname :type type
 112                                                       :case :common))
 113                       what
 114                       thunk)))
 115     (with-parser-context (token-scanner-context :scanner scanner)
 116       (parse (or (seq ("import" (name :string) #\;)
 117                    (common name "SOD" "module"
 118                            (lambda (path true)
 119                              (handler-case
 120                                  (let ((module (read-module path
 121                                                             :truename true)))
 122                                    (when module
 123                                      (module-import module)
 124                                      (pushnew module
 125                                               (module-dependencies
 126                                                *module*))))
 127                                (file-error (error)
 128                                  (cerror* "Error reading module ~S: ~A"
 129                                           path error))))))
 130                  (seq ("load" (name :string) #\;)
 131                    (common name "LISP" "Lisp file"
 132                            (lambda (path true)
 133                              (handler-case
 134                                  (load true :verbose nil :print nil)
 135                                (error (error)
 136                                  (cerror* "Error loading Lisp file ~S: ~A"
 137                                           path error)))))))))))
 138
 139 ;;; Lisp escape.
 140
 141 (define-pluggable-parser module lisp (scanner)
 142   ;; `lisp' s-expression `;'
 143
 144   (with-parser-context (token-scanner-context :scanner scanner)
 145     (parse (seq ((sexp (if (and (eql (token-type scanner) :id)
 146                                 (string= (token-value scanner) "lisp"))
 147                            (let* ((stream (make-scanner-stream scanner))
 148                                   (sexp (read stream t)))
 149                              (scanner-step scanner)
 150                              (values sexp t t))
 151                            (values '((:id "lisp")) nil nil)))
 152                  #\;)
 153              (eval sexp)))))
 154
 155 ;;;--------------------------------------------------------------------------
 156 ;;; Class declarations.
 157
 158 (define-pluggable-parser module class (scanner)
 159   ;; `class' id [`:' id-list] `{' class-item* `}'
 160
 161   (with-parser-context (token-scanner-context :scanner scanner)
 162     (parse (seq ("class"
 163                  (name :id)
 164                  (supers (? (seq (#\: (supers (list (:min 1) :id #\,)))
 165                                  supers)))
 166                  #\{
 167
 168
 169 ;;;----- That's all, folks --------------------------------------------------