Add reader for skribe format.

1 files changed, 58 insertions, 0 deletions

diff --git a/skribe.scm b/skribe.scm
new file mode 100644
index 0000000..c7d8380
--- /dev/null
+++ b/skribe.scm
@@ -0,0 +1,58 @@
+(define-module (skribe)
+  #:use-module ((system reader) #:renamer (symbol-prefix-proc 'r:))
+  #:export (%skribe-reader))
+
+;; Taken from Skribilo
+(define (make-colon-free-token-reader tr)
+  ;; Stolen from `guile-reader' 0.3.
+  "If token reader @var{tr} handles the @code{:} (colon) character, remove it
+from its specification and return the new token reader."
+  (let* ((spec (r:token-reader-specification tr))
+	 (proc (r:token-reader-procedure tr)))
+    (r:make-token-reader (filter (lambda (chr)
+				   (not (char=? chr #\:)))
+				 spec)
+			 proc)))
+
+(define &sharp-reader
+  ;; The reader for what comes after a `#' character.
+  (let* ((dsssl-keyword-reader  ;; keywords à la `#!key'
+          (r:make-token-reader #\!
+ 			       (r:token-reader-procedure
+ 				(r:standard-token-reader 'keyword)))))
+      (r:make-reader (cons dsssl-keyword-reader
+			   (map r:standard-token-reader
+				'(character srfi-4 vector
+				  number+radix boolean
+				  srfi30-block-comment
+				  srfi62-sexp-comment)))
+		     #f ;; use default fault handler
+		     'reader/record-positions)))
+
+(define (make-skribe-reader)
+  (let ((colon-keywords ;; keywords à la `:key' fashion
+	 (r:make-token-reader #\:
+			      (r:token-reader-procedure
+			       (r:standard-token-reader 'keyword))))
+	(symbol-misc-chars-tr
+	 ;; Make sure `:' is handled only by the keyword token reader.
+	 (make-colon-free-token-reader
+	  (r:standard-token-reader 'r6rs-symbol-misc-chars))))
+
+    ;; Note: we use the `r6rs-symbol-*' and `r6rs-number' token readers since
+    ;; they consider square brackets as delimiters.
+    (r:make-reader (cons* (r:make-token-reader #\# &sharp-reader)
+			  colon-keywords
+			  symbol-misc-chars-tr
+			  (map r:standard-token-reader
+			       `(whitespace
+				 sexp string r6rs-number
+				 r6rs-symbol-lower-case
+				 r6rs-symbol-upper-case
+				 quote-quasiquote-unquote
+				 semicolon-comment
+				 skribe-exp)))
+		   #f ;; use the default fault handler
+		   'reader/record-positions)))
+
+(define %skribe-reader (make-skribe-reader))