From: Ferenc Engard <ferenc@...>
Date: 2003-09-06T09:11:26+09:00
Subject: 2 questions about TkVariable and ruby/tk

Hi all!

I have the following code snippet:

-----------------------------------
....
h=Hash.new
(0..4).each {|c|
  (0..9).each {|r|
    h["#{r},#{c}"]="#{r} ; #{c}";
  }
}
v=TkVariable.new(h)
#~ puts "before: #{v.value}"
puts "ok."
t2=TkTable.new() {
  rows 10
  cols 5
  variable v
}
t2.pack()
Tk.mainloop()
-------------------------------------
(TkTable is a wrapper for a tktable tcl widget written by me. It uses
'variable' to store the data of the table cells.)

This works perfectly, just as I expect. BUT, if I comment out the
debugging puts(), then it prints v's content, then 'ok.' just as before,
but after that the program hangs, the X window do not appear, and I
cannot even stop the program with CTRL-C! If I simply just read the
v.value (do not print it), the result is similar. :-O With v.inspect the
problem do not occur. What difference makes reading a TkVariable's
value???

My second question is related to the previous: I have the feeling that
this 'hang' really means a runtime error in the ruby code which is
executed from tcl (which is executed from ruby :). So, my question is
how to receive these error messages, and why do the process hang if it
encounters with an error like this?