where

where( 
[ g_unevaluated ] 
[ x_depth ] 
[ x_skip ] 
[ p_port ] 
) 
=> x_result

Description

Prints the functions on the stack and their arguments to the depth specified, or to the bottom of the stack, including the local variables and their bindings.

It is similar to stacktrace, but in addition to printing out the functions on the stack, it also prints out the local variables and their bindings. The where function observes the following rules:

• When debug mode is on and the traceArgs status switch has been set to non-nil, prints the evaluated function arguments unless g_unevaluated is set to t.
• When debug mode is off, where always prints the unevaluated arguments.
• where skips over the number of function calls specified by x_skip.
• If there are no functions on the stack (you are at the top, for example) where does not print anything and returns 0.

This function is usually used inside the break or error handler.

Arguments

g_unevaluated	Prints the unevaluated function parameters.
x_depth	Number of stack levels to print. The default is all.
x_skip	Number of levels to skip. The default is 1.
p_port	Output port. Defaults to the error port if not specified.

Value Returned

x_result

Number of stack frames printed.

Examples

Suppose /tmp/color.il defines function initColor:

(defun initColor (object)
  (let ((colorList '(red green yellow)) color)
       (setq color (concat (get object 'color)))
       (if (memq color colorList)
           (printf "color %s initialized" (get object 'name)))
  )
)

Try this file in debugger:

installDebugger
=> t
1> (sstatus sourceTracing t) 
                     ; Turns on sourceTracing to get line numbers
=> t

1>  load "/tmp/color.il"
=> t

1> (putprop 'object1 "green" 'color)
=> "green"

1> (initColor 'object1)
*** Error in routine fprintf/sprintf:
Message: *Error* fprintf/sprintf: format spec. incompatible 
with data

Debug 2> where
<<< Stack Trace >>>
errorHandler("fprintf/sprintf" 0 t nil ("*Error* fprintf/sprintf: format spec. incompatible with data" nil))
printf("color %s initialized" get(object 'name))
at line 5 in file /tmp/color.il
if(memq(color colorList) printf("color %s initialized" get(object 'name)))
let(((colorList '&) color) (color = concat(get(object &))) if(memq(color colorList) printf("color %s initialized" get(object &))))
        colorList = (red green yellow)
        color = green
        object = object1
initColor('object1)
5

Related Topics

Debug Functions

sstatus

stacktrace

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