Convert print-source-listings to use keywords.

Makefile

@@ -97,7 +97,7 @@ testing.so: testing.o
 testing.o: testing.import.scm
 testing.import.scm: $(TESTING-SOURCES)
 
-LISTING-SOURCES=listing.scm testing.import.scm
+LISTING-SOURCES=listing.scm testing.import.scm ansi.import.scm
 
 listing.so: listing.o
 listing.o: listing.import.scm

listing.scm

@@ -36,7 +36,9 @@
 	 (chicken base)
 	 (chicken string)
 	 (chicken format)
-	 testing)
+	 (chicken keyword)
+	 testing
+	 ansi)
 
  ;; Returns the number of digits required to represent a given number
  ;; in decimal format.
@@ -108,7 +110,19 @@
 
  ;; Prints and highlights a selection of source listing lines and
  ;; their optional context.
- (define (print-source-listing lines highlights context hl-pre hl-post ctx-pre ctx-post ellipsis)
+ (define (print-source-listing lines highlights . args)
+   (let ((highlight-rules (get-keyword #:highlight-rules args
+				       (lambda ()
+					 '((error (ansi #:bold #:red) (ansi #:default))
+					   (warning (ansi #:yellow) (ansi #:default))
+					   (info (ansi #:cyan) (ansi #:default))
+					   ))))
+	 (ellipsis (get-keyword #:ellipsis args (lambda () "...")))
+	 (ctx-pre (get-keyword #:context-pre args (lambda () "")))
+	 (ctx-post (get-keyword #:context-post args (lambda () "")))
+	 (hl-pre (get-keyword #:highlight-pre args (lambda () a:error)))
+	 (hl-post (get-keyword #:highlight-post args (lambda () a:default)))
+	 (context (get-keyword #:context args (lambda () 3))))
      (let ((digits (number-digits (length lines))))
        (let loop ((lines lines)
 		  (number 1)
@@ -147,7 +161,7 @@
 		    (loop (cdr lines)
 			  (+ number 1)
 			  printed-something
-			#f))))))))
+			  #f)))))))))
 
  ;; Performs self-tests of the listing module.
  (define (listing-tests!)

member-print.scm

@@ -139,10 +139,7 @@
      (print-source-listing
       lines
       hls
-      -1
-      a:error a:default
-      "" "" ; Not used
-      "..." ; Not used
+      #:context -1
       )))
 
  )