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TraceDialog

TraceDialog[expr]
initiates a dialog for every expression used in the evaluation of expr.
TraceDialog[expr, form]
initiates a dialog only for expressions which match form.
TraceDialog[expr, s]
initiates dialogs only for expressions whose evaluations use transformation rules associated with the symbol s.
  • The expression to be evaluated when a dialog is called is given as Out[$Line] of the dialog, wrapped in HoldForm. The expression can be seen by asking for % when the dialog is first started.
  • Any value returned from the dialog is discarded.
  • TraceDialog[expr] returns the result of evaluating expr.
Trace evaluation of an expression, entering a Dialog whenever addition is encountered:
In the dialog you can look at the evaluation stack:
This returns from the first dialog:
Another dialog has started:
In the dialog, you can check evaluations to see if they come out as you expect:
Return from the second dialog. Since there are no more additions, the evaluation will finish:
Trace evaluation of an expression, entering a Dialog whenever addition is encountered:
In[1]:=
Click for copyable input
Out[1]=
Out[1]=
Out[1]=
In the dialog you can look at the evaluation stack:
In[2]:=
Click for copyable input
(Dialog) Out[2]=
This returns from the first dialog:
In[3]:=
Click for copyable input
Another dialog has started:
In[4]:=
Click for copyable input
(Dialog) Out[4]=
In the dialog, you can check evaluations to see if they come out as you expect:
In[5]:=
Click for copyable input
(Dialog) Out[5]=
In[6]:=
Click for copyable input
(Dialog) Out[6]=
Return from the second dialog. Since there are no more additions, the evaluation will finish:
In[7]:=
Click for copyable input
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