prepare_goal(+Goal0, -Goal1, +Options) is semidet[multifile, library(pengines)]
Pre-preparation hook for running Goal0. The hook runs in the context of the pengine. Goal is the raw goal given to ask. The returned Goal1 is subject to goal expansion (expand_goal/2) and sandbox validation (safe_goal/1) prior to execution. If this goal fails, Goal0 is used for further processing.
Options- provides the options as given to ask
 pengines:prepare_goal(+GoalIn, -GoalOut, +Options) is semidet[multifile, wordlist(trace)]
Handle the breakpoints(List) option to set breakpoints prior to execution of the query. If breakpoints are present and enabled, the goal is executed in debug mode. List is a list, holding a dict for each source that has breakpoints. The dict contains these keys:
  • file is the source file. For the current Pengine source this is pengine://<pengine>/src.
  • breakpoints is a list of lines (integers) where to put break points.