Print errors better in the repl

1 files changed, 47 insertions, 0 deletions

diff --git a/repl.pl b/repl.pl
index 8ecf286..0a3d5d2 100644
--- a/repl.pl
+++ b/repl.pl
@@ -75,11 +75,58 @@ write_bindings([Var = Val|Bs]) :-
 	),
 	write_bindings(Bs).
 
+print_exception(error(E, _)) :-
+	write('Unhandled error:
+	'), % \n\t
+	print_error(E),
+	nl.
 print_exception(E) :-
+	E \= error(_,_),
 	write('Unhandled exception: '),
 	write(E),
 	nl.
 
+print_error(instantiation_error) :-
+	write('instantiation error').
+print_error(type_error(ValidType, Culprit)) :-
+	write('type error, expected '),
+	write(ValidType),
+	write(': '),
+	write(Culprit).
+print_error(domain_error(ValidDomain, Culprit)) :-
+	write('domain error, expected '),
+	write(ValidDomain),
+	write(': '),
+	write(Culprit).
+print_error(existence_error(ObjectType, Culprit)) :-
+	write('existence error, '),
+	write(Culprit),
+	write(' is not an existing object of type: '),
+	write(ObjectType).
+print_error(permission_error(Operation, Type, Culprit)) :-
+	write('permission error, cannot '),
+	write(Operation),
+	write(' '),
+	write(Type),
+	write(': '),
+	write(Culprit).
+print_error(representation_error(Flag)) :-
+	write('representation error: '),
+	write(Flag).
+print_error(evaluation_error(Error)) :-
+	write('evaluation error: '),
+	write(Error).
+print_error(resource_error(Res)) :-
+	write('resource error: '),
+	write(Res).
+print_error(syntax_error(E)) :-
+	write('syntax error: '),
+	write(E).
+print_error(system_error) :-
+	write('system error').
+print_error(E) :-
+	write(E).
+
 whitespace(' ').
 whitespace('	').
 whitespace('