[Haskell-beginners] Backtrace when a certain location in the code is executed
bryceverdier at gmail.com
Thu Aug 16 19:05:50 CEST 2012
I'm aware of :break in ghci, and I've used it for "little" functions
that I was trying to understand. I'm not sure how well it'll work for a
large project though.
This is the "debugging" section in ghci when you type ":help":
-- Commands for debugging:
:abandon at a breakpoint, abandon current computation
:back go back in the history (after :trace)
:break [<mod>] <l> [<col>] set a breakpoint at the specified location
:break <name> set a breakpoint on the specified function
:continue resume after a breakpoint
:delete <number> delete the specified breakpoint
:delete * delete all breakpoints
:force <expr> print <expr>, forcing unevaluated parts
:forward go forward in the history (after :back)
:history [<n>] after :trace, show the execution history
:list show the source code around current
:list identifier show the source code for <identifier>
:list [<module>] <line> show the source code around line number
:print [<name> ...] prints a value without forcing its
:sprint [<name> ...] simplifed version of :print
:step single-step after stopping at a breakpoint
:step <expr> single-step into <expr>
:steplocal single-step within the current top-level
:stepmodule single-step restricted to the current module
:trace trace after stopping at a breakpoint
:trace <expr> evaluate <expr> with tracing on (see
I hope this helps.
On 8/16/12 7:31 AM, Nathan Hüsken wrote:
> I am trying to understand haskell program not written by me.
> During runtime one function is called with parameters which makes the
> function throw an error. I want to know from where the function is called.
> In c++ I would set a breakpoint on the error throwing code, and let gdb
> print the backtrace.
> To I have similar options in haskell?
> What other options do I have?
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