6 The DBG Package

print-binding-frames

Variable

Summary

Controls whether binding frames are printed in debugger output.

Package

dbg

Initial Value

nil

Description

This variable is used by the debugger when it displays the stack frames. Binding frames are formed when special variables are bound, but are normally not shown by the debugger. However ifdbg:*print-binding-frames* is set tot then the binding frames are shown.

Example

USER 10 > (defun print-to-length (object length)
   (let ((*print-length* length))
     (prinnt object)))

PRINT-TO-LENGTH 
USER 11 > (setq dbg:*print-binding-frames* t)

T 
USER 12 > (print-to-length '(1 2 3 4 5) 2)

Error: Undefined function: PRINNT  , with args
  ((1 2 ...)) 

1 (continue) Call PRINNT again
   2 (abort) return to top loop level 0.

: Type:c followed by a number to proceed

USER 13 : 1 > :n print-to-length

USER 14 : 1 > :b :verbose 2 
Interpreted call to (DEFUN PRINT-TO-LENGTH): 
*PRINT-LENGTH* : %INTERNAL-SPECIAL-MARKER% 
LENGTH : 2 OBJECT : (1 2 3 4 5) 
Binding frame: %BENV%,NIL

Notes
: *print-binding-frames* is an extension to Common Lisp.