The stack information object. The intrinsic function t3GetStackTrace() in the 't3vm' function set returns a list of these objects; each object represents a level in the stack trace.

class T3StackInfo :   object

Superclass Tree   (in declaration order)


Subclass Tree  


Global Objects  


Summary of Properties  

argList_  frameDesc_  func_  locals_  namedArgs_  obj_  prop_  self_  srcInfo_ 

Summary of Methods  

construct  isSystem 



The list of positional arguments to the function or method. Each element is the value of an argument; the list is arranged in the same order as the arguments.

A StackFrameDesc object that can be used to get information from the frame and change local variables in the frame.

the function running at this stack level - this is nil if an object property is running instead of a function

Local variables. This is a LookupTable containing the local variables currently in scope at this stack level. Each element in the table has a string key (index) giving the name of the local variable, and each corresponding value is the local's current value. The table is only included when the stack listing was produced by a call to t3GetStackTrace() with the T3GetStackLocals flag set; otherwise it's nil. If the locals were requested, and the stack level has no local variables, this will be an empty lookup table.

Named arguments. This is a LookupTable containing the named arguments passed in from this stack level. Each element in the table has a string key (index) giving the name of the argument, and each corresponding value is the value of that argument. If there are no named arguments, this value is nil.

The object and property running at this stack level - these are nil if a function is running instead of an object method. The object is the object where the method is actually defined - this might not be the same as self, because the object might have inherited the method from a base class.

no description available

the 'self' object at this level - this is nil if a function is running at this level instead of an object method

The source location of the next code to be executed in the function or method in this frame. If source-level debugging information is available for the current execution point in this frame, this will contain a list of two values:

srcInfo_[1] = string giving the name of the source file
srcInfo_[2] = integer giving the line number in the source file

If the program wasn't compiled with source-level debugging information, or the current code location in the frame doesn't have any source information, this will be set to nil.

Note that the location reflected here is the *return address* in this frame - that is, the code location that will be executed when control returns to the frame. This means that the source location will frequently appear as the next executable line after the one that called the next inner frame, because this is where execution will resume when control returns to the frame.


construct (func, obj, prop, selfObj, argList, srcInfo, locals, namedArgs, frameDesc)_main.t[1008]

Construct a stack level object. The system invokes this constructor with information on the stack level.

isSystem ( )_main.t[1027]
Is this a system routine? This returns true if an intrinsic function or an intrinsic class method is running at this level.

TADS 3 Library Manual
Generated on 5/16/2013 from TADS version 3.1.3