Implementation of the Debugger

Prolog code to do debugging. More...

Detailed Description

Prolog code to do debugging.

• The debugger is an interpreter with main predicates:
  • $trace: this is the API
  • trace_goal: reduce a query to a goal
  • trace_goal: execute:
    • using the source, Luke
    • hooking into the WAM procedure call mechanism
    • asking Prolog to do it (system_library-builtins)
• |flag | description | initial | possible values | -------------------------------------------------------------—
• | spy_gn | last goal number | 1 | 1...
• | spy_trace | trace | 0 | 0, 1
• | spy_status | step | creep | creep,leap,skip
• | ... | | stop at goal | -1 | Integer >= 1
• | ... | | stop at spy-points | stop | stop,

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Class Documentation

trace_goal/4

class trace_goal/4

trace_goal( +G, +M, +GoalNumber, +CP)

% debug a complex query %