Hi-
I find that the backtrace output in the REPL is too constrained
my verbose code. The attached patch would let one set the
width of the backtrace and locals meta-commands.
What do you think?
-Mike
From 781bcc2783709e76591cd354f4976f02eb284526 Mon Sep 17 00:00:00 2001
From: Michael Gran <spk...@yahoo.com>
Date: Sun, 20 Feb 2011 21:53:46 -0800
Subject: [PATCH] Add ,width meta-command to set screen width in debug output
This meta-command allows one to set the default number of columns
that output from ,backtrace and ,locals shall occupy.
* doc/ref/scheme-using.texi (Debug Commands): document ,width
* module/system/repl/command.scm (*width*): new var
(backtrace, locals): use *width* in optarg
(width): new meta-command
---
doc/ref/scheme-using.texi | 6 ++++++
module/system/repl/command.scm | 21 ++++++++++++++++++---
2 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/doc/ref/scheme-using.texi b/doc/ref/scheme-using.texi
index 126b845..a119d42 100644
--- a/doc/ref/scheme-using.texi
+++ b/doc/ref/scheme-using.texi
@@ -337,6 +337,12 @@ Show the VM registers associated with the current frame.
@xref{Stack Layout}, for more information on VM stack frames.
@end deffn
+@deffn {REPL Command} width [cols]
+Sets the number of display columns in the output of @code{,backtrace}
+and @code{,locals} to @var{cols}. If @var{cols} is not given, the width
+of the terminal is used.
+@end deffn
+
The next 3 commands work at any REPL.
@deffn {REPL Command} break proc
diff --git a/module/system/repl/command.scm b/module/system/repl/command.scm
index d4b3e4a..40d720d 100644
--- a/module/system/repl/command.scm
+++ b/module/system/repl/command.scm
@@ -71,6 +71,8 @@
(define *show-table*
'((show (warranty w) (copying c) (version v))))
+(define *width* 72)
+
(define (group-name g) (car g))
(define (group-commands g) (cdr g))
@@ -546,7 +548,7 @@ Trace execution."
(format #t "Nothing to debug.~%"))))))))
(define-stack-command (backtrace repl #:optional count
- #:key (width 72) full?)
+ #:key (width *width*) full?)
"backtrace [COUNT] [#:width W] [#:full? F]
Print a backtrace.
@@ -626,12 +628,12 @@ With an argument, select a frame by index, then show it."
Print the procedure for the selected frame."
(repl-print repl (frame-procedure cur)))
-(define-stack-command (locals repl)
+(define-stack-command (locals repl #:key (width *width*))
"locals
Show local variables.
Show locally-bound variables in the selected frame."
- (print-locals cur))
+ (print-locals cur #:width width))
(define-stack-command (error-message repl)
"error-message
@@ -811,6 +813,19 @@ Print registers.
Print the registers of the current frame."
(print-registers cur))
+(define-meta-command (width repl #:optional x)
+ "width [X]
+Set debug output width.
+
+Set the number of screen columns in the output from `backtrace' and
+`locals'."
+ (if (and x (not (integer? x)))
+ (error "expected a column number (a non-negative integer)" x)
+ (let ((w (or x
+ (false-if-exception (string->number (getenv "COLUMNS")))
+ 72)))
+ (format #t "Setting screen width to ~a columns~%" w)
+ (set! *width* w))))
;;;
--
1.7.4
