Patch for ice-9/format.scm (removes arbitrary ~{...~} iteration limit)

[Matthias Koeppe]

Today I tried to format a long list of elements using the format "~{"
directive.  To my surprise, the list was cut off after the 100th
element.  

I am sending a testcase for Guile's test suite and a patch that fixes
the problem.  The patch is against the stable branch, where it should
be applied in addition to the CVS HEAD.


2004-05-25  Matthias Koeppe  <address@hidden>

        * format.scm (format): Remove the arbitrary limit of 100 iterations
        for the ~{...~} control structure.


Index: ice-9/format.scm
===================================================================
RCS file: /cvsroot/guile/guile/guile-core/ice-9/format.scm,v
retrieving revision 1.11.2.2
diff -u -p -r1.11.2.2 format.scm
--- ice-9/format.scm    13 Jan 2004 16:56:11 -0000      1.11.2.2
+++ ice-9/format.scm    25 May 2004 14:17:06 -0000
@@ -614,8 +614,7 @@
               (case modifier
                 ((colon)
                  (if (not max-iterations) (set! max-iterations 1)))
-                ((colon-at at) (format:error "illegal modifier"))
-                (else (if (not max-iterations) (set! max-iterations 100))))
+                ((colon-at at) (format:error "illegal modifier")))
               (if (not (null? params))
                   (format:error "no parameters allowed in ~~}"))
               (if (zero? iteration-nest)
@@ -637,7 +636,8 @@
                                            (list-tail args arg-pos))))
                             (i 0 (+ i 1)))
                            ((or (>= arg-pos args-len)
-                                (>= i max-iterations))))))
+                                (and max-iterations
+                                     (>= i max-iterations)))))))
                     ((sublists)
                      (let ((args (next-arg))
                            (args-len 0))
@@ -646,7 +646,8 @@
                        (set! args-len (length args))
                        (do ((arg-pos 0 (+ arg-pos 1)))
                            ((or (>= arg-pos args-len)
-                                (>= arg-pos max-iterations)))
+                                (and max-iterations
+                                     (>= arg-pos max-iterations))))
                          (let ((sublist (list-ref args arg-pos)))
                            (if (not (list? sublist))
                                (format:error
@@ -663,7 +664,8 @@
                                                   args arg-pos))))
                                   (i 0 (+ i 1)))
                                  ((or (>= arg-pos args-len)
-                                      (>= i max-iterations))
+                                      (and max-iterations
+                                           (>= i max-iterations)))
                                   arg-pos))))
                        (add-arg-pos usedup-args)))
                     ((rest-sublists)
@@ -672,7 +674,8 @@
                             (usedup-args
                              (do ((arg-pos 0 (+ arg-pos 1)))
                                  ((or (>= arg-pos args-len)
-                                      (>= arg-pos max-iterations))
+                                      (and max-iterations
+                                           (>= arg-pos max-iterations)))
                                   arg-pos)
                                (let ((sublist (list-ref args arg-pos)))
                                  (if (not (list? sublist))
Index: test-suite/tests/format.test
===================================================================
RCS file: /cvsroot/guile/guile/guile-core/test-suite/tests/format.test,v
retrieving revision 1.1
diff -u -p -r1.1 format.test
--- test-suite/tests/format.test        16 Jun 2001 20:11:39 -0000      1.1
+++ test-suite/tests/format.test        25 May 2004 14:17:06 -0000
@@ -1,7 +1,7 @@
 ;;;; format.test --- test suite for Guile's CL-ish format  -*- scheme -*-
 ;;;; Matthias Koeppe <address@hidden> --- June 2001
 ;;;;
-;;;;   Copyright (C) 2001 Free Software Foundation, Inc.
+;;;;   Copyright (C) 2001, 2003, 2004 Free Software Foundation, Inc.
 ;;;;
 ;;;; This program is free software; you can redistribute it and/or modify
 ;;;; it under the terms of the GNU General Public License as published by
@@ -36,4 +36,10 @@
                (format #t "~&abc")
                (format #f "~&")        ; shall have no effect
                (format #t "~&~&")))
-           "xyz\nabc\n")))
+           "xyz\nabc\n"))
+  (pass-if "format ~F (format-out-substr) maintains the column correctly"
+          (= (string-length (format "address@hidden" 1)) 20)))
+
+(with-test-prefix "format control flow"
+  (pass-if "format ~{ has no arbitrary iteration limit"
+          (= (string-length (format "~{~a~}" (make-list 200 #\b))) 200)))
\ No newline at end of file

-- 
Matthias Koeppe -- http://www.math.uni-magdeburg.de/~mkoeppe