If you wish to examine the arguments to the functions present in the
stack backtrace, you need to do three things while the exception is
still present in *e:
(collect)- reproduce the exception
(analyze)
Collect will "hook" all of the functions for which zpst can find source in the stack backtrace. In addition to collecting the arguments to each of these functions, it will also capture all of the thread-local bindings at each function invocation. It will also capture all of the var redefinitions for every namespace explicitly specified by the user. These namespaces are specified by:
{:ns '[<ns-1> <ns-2> ... <ns-n>]}You don't have to specify individual vars, but you do have to specify
namespaces. Th is is only necessary if you wish to use the
(re-eval) capability to initiate a call from any frame in the
database and if any of the functions on the stack have actually
redefined any vars. One hint that things might have been redefined is
any use of clojure.core/with-redefs or clojure.core/with-redefs-fn.
The default value for :ns is {:ns '[zprint.zfns]} which covers
the functions uthat are redefined in the zprint library (from which
the example was drawn). If you wish to experiment with recreating
the example in the overview, you can do so without having to figure
out that zprint redefines some of the vars in the zprint.zfns
namespace. You will want to replace this value if you want to
use (re-eval) with your own code that redefines vars.
Once you have run collect, you should reproduce the exception and
then immediately run analyze to gather the data from the exception
and to "unhook" the functions.
Analyze will take the exception generated by reproducing the exception and turn the information in that exception into a database of frames that the commands will operate on.
It will also "unhook" all of the functions that collect hooked.