* optargs.scm: Replaced `#&' reader syntax with keywords.

ice-9/optargs.scm

@@ -48,9 +48,9 @@
 ;;; Summary of the lambda* extended parameter list syntax (brackets
 ;;; are used to indicate grouping only):
 ;;;
-;;; ext-param-list ::= [identifier]* [#&optional [ext-var-decl]+]?
-;;;   [#&key [ext-var-decl]+ [#&allow-other-keys]?]? 
-;;;   [[#&rest identifier]|[. identifier]]?
+;;; ext-param-list ::= [identifier]* [#:optional [ext-var-decl]+]?
+;;;   [#:key [ext-var-decl]+ [#:allow-other-keys]?]? 
+;;;   [[#:rest identifier]|[. identifier]]?
 ;;;
 ;;; ext-var-decl ::= identifier | ( identifier expression )  
 ;;;
@@ -195,44 +195,15 @@
 		  accum
 		  (loop (car rest) (cdr rest) accum)))))))
 
-
-;;   reader extensions for #&optional #&key #&allow-other-keys #&rest
-;; These need to be quoted in normal code, but need not be in
-;; an extended lambda-list provided by lambda*, define*, or 
-;; define*-public (see below). In other words, they act sort of like 
-;; symbols, except they aren't. They're being temporarily used until
-;; #!optional and #!key and such are available. #&rest is provided for
-;; the convenience of confused Common Lisp users, even though `.' will 
-;; do just as well.
-
-(define the-optional-value 
-  ((record-constructor (make-record-type
-			'optional '() (lambda (o p)
-					(display "#&optional"))))))
-
-(define the-key-value 
-  ((record-constructor (make-record-type 
-			'key '() (lambda (o p)
-				   (display "#&key"))))))
-
-
-(define the-rest-value 
-  ((record-constructor (make-record-type 
-			'rest '() (lambda (o p)
-					(display "#&rest" p))))))
-
-(define the-allow-other-keys-value
-  ((record-constructor (make-record-type 
-			'allow-other-keys '() (lambda (o p)
-					(display "#&allow-other-keys" p))))))
-
+;; This is a reader extension to support the (deprecated) use of
+;; "#&optional" instead of "#:optional"
 
 (read-hash-extend #\& (lambda (c port)
 			(case (read port)
-			  ((optional) the-optional-value)
-			  ((key) the-key-value)
-			  ((rest) the-rest-value)
-			  ((allow-other-keys) the-allow-other-keys-value)
+			  ((optional) #:optional)
+			  ((key) #:key)
+			  ((rest) #:rest)
+			  ((allow-other-keys) #:allow-other-keys-value)
 			  (else (error "Bad #& value.")))))
 
 
@@ -242,7 +213,7 @@
 ;; lambda* creates a procedure that takes optional arguments. These
 ;; are specified by putting them inside brackets at the end of the
 ;; paramater list, but before any dotted rest argument. For example,
-;;   (lambda* (a b #&optional c d . e) '())
+;;   (lambda* (a b #:optional c d . e) '())
 ;; creates a procedure with fixed arguments a and b, optional arguments c
 ;; and d, and rest argument e. If the optional arguments are omitted
 ;; in a call, the variables for them are unbound in the procedure. This
@@ -250,7 +221,7 @@
 ;;
 ;; lambda* can also take keyword arguments. For example, a procedure
 ;; defined like this:
-;;   (lambda* (#&key xyzzy larch) '())
+;;   (lambda* (#:key xyzzy larch) '())
 ;; can be called with any of the argument lists (#:xyzzy 11)
 ;; (#:larch 13) (#:larch 42 #:xyzzy 19) (). Whichever arguments
 ;; are given as keywords are bound to values.
@@ -258,7 +229,7 @@
 ;; Optional and keyword arguments can also be given default values
 ;; which they take on when they are not present in a call, by giving a
 ;; two-item list in place of an optional argument, for example in:
-;;   (lambda* (foo #&optional (bar 42) #&key (baz 73)) (list foo bar baz)) 
+;;   (lambda* (foo #:optional (bar 42) #:key (baz 73)) (list foo bar baz)) 
 ;; foo is a fixed argument, bar is an optional argument with default
 ;; value 42, and baz is a keyword argument with default value 73.
 ;; Default value expressions are not evaluated unless they are needed
@@ -268,17 +239,17 @@
 ;;
 ;; lambda*-defined procedures now throw an error by default if a
 ;; keyword other than one of those specified is found in the actual
-;; passed arguments. However, specifying #&allow-other-keys
+;; passed arguments. However, specifying #:allow-other-keys
 ;; immediately after the kyword argument declarations restores the
 ;; previous behavior of ignoring unknown keywords. lambda* also now
 ;; guarantees that if the same keyword is passed more than once, the
 ;; last one passed is the one that takes effect. For example,
-;;   ((lambda* (#&key (heads 0) (tails 0)) (display (list heads tails)))
+;;   ((lambda* (#:key (heads 0) (tails 0)) (display (list heads tails)))
 ;;    #:heads 37 #:tails 42 #:heads 99)
 ;; would result in (99 47) being displayed.
 ;;
-;; #&rest is also now provided as a synonym for the dotted syntax rest
-;; argument. The argument lists (a . b) and (a #&rest b) are equivalent in
+;; #:rest is also now provided as a synonym for the dotted syntax rest
+;; argument. The argument lists (a . b) and (a #:rest b) are equivalent in
 ;; all respects to lambda*. This is provided for more similarity to DSSSL,
 ;; MIT-Scheme and Kawa among others, as well as for refugees from other
 ;; Lisp dialects.
@@ -345,27 +316,27 @@
      (else (cont lst '() #f))))
   (define (parse-opt-and-fixed arglist keys aok? rest cont)
     (split-list-at
-     '#&optional arglist
+     #:optional arglist
      (lambda (before after split?)
        (if (and split? (null? after))
-	   (error "#&optional specified but no optional arguments declared.")
+	   (error "#:optional specified but no optional arguments declared.")
 	   (cont before after keys aok? rest)))))
   (define (parse-keys arglist rest cont)
     (split-list-at 
-     '#&allow-other-keys arglist
+     #:allow-other-keys arglist
      (lambda (aok-before aok-after aok-split?)
        (if (and aok-split? (not (null? aok-after)))
-	   (error "#&allow-other-keys not at end of keyword argument declarations.")
+	   (error "#:allow-other-keys not at end of keyword argument declarations.")
 	   (split-list-at 
-	    '#&key aok-before
+	    #:key aok-before
 	    (lambda (key-before key-after key-split?)
 	      (cond 
 	       ((and aok-split? (not key-split?))
-		(error "#&allow-other-keys specified but no keyword arguments declared."))
+		(error "#:allow-other-keys specified but no keyword arguments declared."))
 	       (key-split? 
 		(cond
-		 ((null? key-after) (error "#&key specified but no keyword arguments declared."))
-		 ((memq '#&optional key-after) (error "#&optional arguments declared after #&key arguments."))
+		 ((null? key-after) (error "#:key specified but no keyword arguments declared."))
+		 ((memq #:optional key-after) (error "#:optional arguments declared after #:key arguments."))
 		 (else (parse-opt-and-fixed key-before key-after aok-split? rest cont))))
 	       (else (parse-opt-and-fixed arglist '() #f rest cont)))))))))
   (define (parse-rest arglist cont)
@@ -377,17 +348,17 @@
 		 (lp (last-pair copy))
 		 (ra (cdr lp)))
 	    (set-cdr! lp '())
-	    (if (memq '#&rest copy)
-		(error "Cannot specify both #&rest and dotted rest argument.")
+	    (if (memq #:rest copy)
+		(error "Cannot specify both #:rest and dotted rest argument.")
 		(parse-keys copy ra cont))))
      (else (split-list-at 
-	    '#&rest arglist 
+	    #:rest arglist 
 	    (lambda (before after split?)
 	      (if split?
 		  (case (length after)
-		    ((0) (error "#&rest not followed by argument."))
+		    ((0) (error "#:rest not followed by argument."))
 		    ((1) (parse-keys before (car after) cont))
-		    (else (error "#&rest argument must be declared last.")))
+		    (else (error "#:rest argument must be declared last.")))
 		  (parse-keys before #f cont)))))))
 
   (parse-rest arglist cont))
@@ -401,16 +372,16 @@
 ;; define* and define*-public support optional arguments with
 ;; a similar syntax to lambda*. They also support arbitrary-depth
 ;; currying, just like Guile's define. Some examples:
-;;   (define* (x y #&optional a (z 3) #&key w . u) (display (list y z u)))
+;;   (define* (x y #:optional a (z 3) #:key w . u) (display (list y z u)))
 ;; defines a procedure x with a fixed argument y, an optional agument
 ;; a, another optional argument z with default value 3, a keyword argument w,
 ;; and a rest argument u.
-;;   (define-public* ((foo #&optional bar) #&optional baz) '())
+;;   (define-public* ((foo #:optional bar) #:optional baz) '())
 ;; This illustrates currying. A procedure foo is defined, which,
 ;; when called with an optional argument bar, returns a procedure that
 ;; takes an optional argument baz. 
 ;;
-;; Of course, define*[-public] also supports #&rest and #&allow-other-keys
+;; Of course, define*[-public] also supports #:rest and #:allow-other-keys
 ;; in the same way as lambda*.
 
 (defmacro-public define* (ARGLIST . BODY)
@@ -442,10 +413,10 @@
 ;;   defmacro and defmacro-public extended for optional and keyword arguments
 ;; 
 ;; These are just like defmacro and defmacro-public except that they
-;; take lambda*-style extended paramter lists, where #&optional,
-;; #&key, #&allow-other-keys and #&rest are allowed with the usual
+;; take lambda*-style extended paramter lists, where #:optional,
+;; #:key, #:allow-other-keys and #:rest are allowed with the usual
 ;; semantics. Here is an example of a macro with an optional argument:
-;;   (defmacro* transmorgify (a #&optional b)
+;;   (defmacro* transmorgify (a #:optional b)
 
 (defmacro-public defmacro* (NAME ARGLIST . BODY)
   (defmacro*-guts 'define NAME ARGLIST BODY))