(defun scan-c-fragment (scanner end-chars)
"Parse a C fragment from the SCANNER.
- SCANNER must be a `sod-token-scanner' instance.
+ SCANNER must be a `sod-token-scanner' instance. The END-CHARS are a
+ sequence of characters, any of which delimits the fragment. The
+ delimiting character is left current in the scanner.
The parsing process is a simple approximation to C lexical analysis. It
takes into account comments (both C and C++ style), string and character
((satisfies whitespace-char-p) (parse :whitespace))
((scan-comment char-scanner))
- ;; See if we've reached the end. There's a small trick here: I
- ;; capture the result in the `if-char' consequent to ensure
- ;; that we don't include the delimiter.
- ((if-char () (and (null delim) (member it end-chars))
- (values (result) t t)
- (values end-chars nil nil))
+ ;; See if we've reached the end. We must leave the delimiter
+ ;; in the scanner, so `if-char' and its various friends aren't
+ ;; appropriate.
+ ((lisp (if (and (null delim)
+ (member (scanner-current-char char-scanner)
+ end-chars))
+ (values (result) t t)
+ (values end-chars nil nil)))
(return (values it t t)))
(:eof
(lexer-error char-scanner '(:any) cp)
(lexer-error char-scanner exp cp)))))))))
(export 'parse-delimited-fragment)
-(defun parse-delimited-fragment (scanner begin end)
+(defun parse-delimited-fragment (scanner begin end &key keep-end)
"Parse a C fragment delimited by BEGIN and END.
- The BEGIN and END arguments are characters. (Currently, BEGIN can be any
- token type, but you probably shouldn't rely on this.)"
+ The BEGIN and END arguments are the start and end delimiters. BEGIN can
+ be any token type, but is usually a delimiter character; it may also be t
+ to mean `don't care' -- but there must be an initial token of some kind
+ for annoying technical reasons. END may be either a character or a list
+ of characters. If KEEP-END is true, the trailing delimiter is left in the
+ token scanner so that it's available for further parsing decisions: this
+ is probably what you want if END is a list."
;; This is decidedly nasty. The basic problem is that `scan-c-fragment'
;; works at the character level rather than at the lexical level, and if we
- ;; commit to the `[' too early then `scanner-step' will eat the first few
- ;; characters of the fragment -- and then the rest of the parse will get
- ;; horrifically confused.
-
- (if (eql (token-type scanner) begin)
- (multiple-value-prog1 (values (scan-c-fragment scanner (list end)) t t)
- (scanner-step scanner))
+ ;; commit to the BEGIN character too early then `scanner-step' will eat the
+ ;; first few characters of the fragment -- and then the rest of the parse
+ ;; will get horrifically confused.
+
+ (if (if (eq begin t)
+ (not (scanner-at-eof-p scanner))
+ (eql (token-type scanner) begin))
+ (multiple-value-prog1 (values (scan-c-fragment scanner
+ (if (listp end)
+ end
+ (list end)))
+ t t)
+ (scanner-step scanner)
+ (unless keep-end (scanner-step scanner)))
(values (list begin) nil nil)))
;;;----- That's all, folks --------------------------------------------------
;;;--------------------------------------------------------------------------
;;; Class declarations.
+(defun parse-class-body (scaner pset name supers)
+ ;; class-body ::= `{' class-item* `}'
+ (with-parser-context (token-scanner-context :scanner scanner)
+ (make-class-type name)
+ (let* ((class (make-sod-class name (mapcat #'find-sod-class supers)
+ pset scanner))
+ (nick (sod-class-nickname class)))
+
+ (labels ((parse-maybe-dotted-declarator (base-type)
+ ;; Parse a declarator or dotted-declarator, i.e., one whose
+ ;; centre is
+ ;;
+ ;; maybe-dotted-identifier ::= [id `.'] id
+ ;;
+ ;; A plain identifier is returned as a string, as usual; a
+ ;; dotted identifier is returned as a cons cell of the two
+ ;; names.
+ (parse-declarator
+ scanner base-type
+ :centre (parser ()
+ (seq ((name-a :id)
+ (name-b (? (seq (#\. (id :id)) id))))
+ (if name-b (cons name-a name-b)
+ name-a)))))
+
+ ;; class-item ::= [property-set] raw-class-item
+ ;;
+
+ (parse-message-item (sub-pset type name)
+ ;; message-item ::=
+ ;; declspec+ declarator -!- (method-body | `;')
+ (make-sod-message class name type sub-pset scanner)
+ (parse (or #\; (parse-method-item nil type nick name))))
+
+ (parse-method-item (sub-pset type sub-nick name)
+ ;; method-item ::=
+ ;; declspec+ dotted-declarator -!- method-body
+ ;;
+ ;; method-body ::= `{' c-fragment `}' | `extern' `;'
+ (parse (seq ((body (or (seq ("extern" #\;) nil)
+ (parse-delimited-fragment
+ scanner #\{ #\}))))
+ (make-sod-method class sub-nick name type
+ body sub-pset scanner))))
+
+ (parse-initializer ()
+ ;; initializer ::= `=' c-fragment | `=' `{' c-fragment `}'
+ ;;
+ ;; Return (VALUE-KIND . VALUE-FORM), ready for passing to a
+ ;; `sod-initializer' constructor.
+ (parse (or (peek (seq (#\= (frag (parse-delimited-fragment
+ scanner #\{ #\})))
+ (cons :compound frag)))
+ (seq ((frag (parse-delimited-fragment
+ scanner #\= '(#\; #\,)
+ :keep-end t)))
+ (cons :simple frag)))))
+
+ (parse-slot-item (sub-pset base-type type name)
+ ;; slot-item ::=
+ ;; declspec+ declarator -!- [initializer]
+ ;; [`,' init-declarator-list] `;'
+ ;;
+ ;; init-declarator-list ::=
+ ;; declarator [initializer] [`,' init-declarator-list]
+ (parse (and (seq ((init (? (parse-initializer))))
+ (make-sod-slot class name type
+ sub-pset scanner)
+ (when init
+ (make-sod-instance-initializer
+ class nick name (car init) (cdr init)
+ nil scanner)))
+ (skip-many ()
+ (seq (#\,
+ (ds (parse-declarator scanner
+ base-type))
+ (init (? (parse-initializer))))
+ (make-sod-slot class (cdr ds) (car ds)
+ sub-pset scanner)
+ (when init
+ (make-sod-instance-initializer
+ class nick (cdr ds)
+ (car init) (cdr init)
+ nil scanner))))
+ #\;)))
+
+ (parse-initializer-item (sub-pset constructor)
+ ;; initializer-item ::=
+ ;; [`class'] -!- slot-initializer-list `;'
+ ;;
+ ;; slot-initializer ::= id `.' id initializer
+ (parse (and (skip-many ()
+ (seq ((name-a :id) #\. (name-b :id)
+ (init (parse-initializer)))
+ (funcall constructor class
+ name-a name-b
+ (car init) (cdr init)
+ sub-pset scanner))
+ #\,)
+ #\;)))
+
+ (class-item-dispatch (sub-pset base-type type name)
+ ;; Logically part of `parse-raw-class-item', but the
+ ;; indentation was getting crazy. We're currently at
+ ;;
+ ;; raw-class-item ::=
+ ;; declspec+ (declarator | dotted-declarator) -!- ...
+ ;; | other-items
+ ;;
+ ;; If the declarator is dotted then this must be a method
+ ;; definition; otherwise it might be a message or slot.
+ (cond ((not (typep type 'c-function-type))
+ (when (consp name)
+ (cerror*-with-location
+ scanner
+ "Method declarations must have function type.")
+ (setf name (cdr name)))
+ (parse-slot-item sub-pset base-type type name))
+ ((consp name)
+ (parse-method-item sub-pset type
+ (car name) (cdr name)))
+ (t
+ (parse-message-item sub-pset type name))))
+
+ (parse-raw-class-item (sub-pset)
+ ;; raw-class-item ::=
+ ;; message-item
+ ;; | method-item
+ ;; | slot-item
+ ;; | initializer-item
+ ;;
+ ;; Most of the above begin with declspecs and a declarator
+ ;; (which might be dotted). So we parse that here and
+ ;; dispatch based on what we find.
+ (parse (or (peek
+ (seq ((ds (parse-c-type scanner))
+ (dc (parse-maybe-dotted-declarator ds))
+ (result (class-item-dispatch sub-pset
+ ds
+ (car dc)
+ (cdr dc))))
+ result))
+ (and "class"
+ (parse-initializer-item
+ sub-pset
+ #'make-sod-class-initializer))
+ (parse-initializer-item
+ sub-pset
+ #'make-sod-instance-initializer)))))
+
+ (parse (and #\{
+ (skip-many ()
+ (seq ((sub-pset (? (parse-property-set)))
+ (nil (parse-raw-class-item sub-pset)))))
+ #\}))))))
+
(define-pluggable-parser module class (scanner)
- ;; `class' id [`:' id-list] `{' class-item* `}'
+ ;; `class' id [`:' id-list] class-body
+ ;; `class' id `;'
(with-parser-context (token-scanner-context :scanner scanner)
- (labels ((parse-item ()
- ;; class-item ::= property-set
+ (parse (seq ("class"
+ (name :id)
+ (nil (or (seq (#\;)
+ (make-class-type name))
+ (seq ((supers (? (seq (#\: (ids (list () :id #\,)))
+ ids)))
+ (nil (parse-class-body
+ scanner
+ pset name supers)))))))))))
+
+
+
+
(parse (seq ("class"
(name :id)
(supers (? (seq (#\: (supers (list (:min 1) :id #\,)))
;;; along with SOD; if not, write to the Free Software Foundation,
;;; Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+(in-package #:sod)
+
;;;--------------------------------------------------------------------------
;;; The expression parser.
(export 'parse-property-set)
(defun parse-property-set (scanner)
- "Parse an optional property set from the SCANNER and return it, or `nil'."
- ;; property-set ::= [`[' property-list `]']
+ "Parse an optional property set from the SCANNER and return it."
+ ;; property-set ::= `[' property-list `]'
(with-parser-context (token-scanner-context :scanner scanner)
- (parse (? (seq (#\[
- (pset (many (pset (make-property-set) pset)
- (parse-property scanner pset)
- #\,))
- #\])
- pset)))))
+ (parse (seq (#\[
+ (pset (many (pset (make-property-set) pset)
+ (parse-property scanner pset)
+ #\,))
+ #\])
+ pset))))
;;;----- That's all, folks --------------------------------------------------
~mdw / sod / commitdiff