[Haskell-cafe] ghci debugger problem with :continue. is it broken, or is it me?

[Thomas Hartman]

In the program below, can someone explain the following debugger output to me?

  After :continue, shouldn't I hit the f breakpoint two more times?
  Why do I only hit the f breakpoint once?
  Is this a problem in the debugger?

thartman at ubuntu:~/haskell-learning/debugger>cat debugger.hs


-- try this:
-- ghci debugger.hs
-- > :break f
-- > :trace t
-- > :history -- should show you that f was called from h
t = h . g . f $ "hey!"
t2 = h . g . f $ "heh!"
t3 = h . g . f $ "wey!"

f = ("f -- " ++)
g = ("g -- " ++)
h = ("h -- " ++)



ts = do
  putStrLn $ t
  putStrLn $ t2
  putStrLn $ t3

{-
Problems using :continue in the ghci debugger?

Can someone explain the following debugger output to me?
  After :continue, shouldn't I hit the f breakpoint two more times?
  Why do I only hit the f breakpoint once?
  Is this a problem in the debugger?

thartman at ubuntu:~/haskell-learning/debugger>ghci debugger.hs
GHCi, version 6.10.1: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer ... linking ... done.
Loading package base ... linking ... done.
[1 of 1] Compiling Main             ( debugger.hs, interpreted )
Ok, modules loaded: Main.
*Main> :break f
Breakpoint 0 activated at debugger.hs:12:4-15
*Main> ts
h -- g -- Stopped at debugger.hs:12:4-15
_result :: [Char] -> [Char] = _
11
12  f = ("f -- " ++)
        ^^^^^^^^^^^^
13  g = ("g -- " ++)
[debugger.hs:12:4-15] *Main> :continue
f -- hey!
h -- g -- f -- heh!
h -- g -- f -- wey!
*Main>
-}