menu_book Course Curriculum (Prolog) expand_more
setup_call_cleanup
Learn setup_call_cleanup in Prolog through a focused explanation, a dedicated construct-specific example, an engineering boundary, and a mastery check.
setup_call_cleanup is an atomic Prolog topic inside Control & Meta. This lesson focuses on how the setup_call_cleanup construct is written, what it changes, and when it is the right tool.
Trace the example line by line. Identify the exact syntax for setup_call_cleanup, the input state before it runs, and the resulting value, control flow, database state, hardware behavior, or runtime effect afterward. Neighboring lessons use different constructs rather than renamed copies of this one.
Topic-specific example
read_first_line(File,Line) :- setup_call_cleanup(open(File,read,S), read_line_to_string(S,Line), close(S)).For setup_call_cleanup, test the boundary that belongs to this exact feature rather than a generic failure case. Check invalid or empty input, NULL/unknown state, numeric limits, transaction or exception behavior, synthesis/runtime constraints, ownership/permission rules, or backtracking/control-flow effects where they apply.