A recent(?) update to swipl changed the error format from
Warning: some.pl:2:
Singleton variables: [Y]
to
Warning: some.pl:2:
Warning: Singleton variables: [Y]
The old error handler doesn't report the correct line numbers and
messages on the old format.
I've chosen to add a function that covers the second case and detect it,
rather than rewrite the current function. This way, both versions should
be able to live together.
---
Example file that demonstrates the issue (some.pl above):
```
% vim: ft=prolog
ii(X, Y) :- X.
```
---
* add prolog/swipl linter
* use load_files/2 instead of read_term/2
Because it also checks some semantic warnings / errors
not only syntactic warnings / errors.
e.g.:
* singleton warning
* discontiguous warning
* ...
cf. http://www.swi-prolog.org/pldoc/doc_for?object=style_check/1
* support error messages with no line number
:- module(module_name, [pred/0]).
causes
ERROR: Exported procedure module_name:pred/0 is not defined
* add test for prolog/swipl handler
* cosmetic fixes
* detect timeout using SIGALRM
* rename g:prolog_swipl_goals to g:prolog_swipl_load
* write doc for prolog/swipl linter
* update toc and README
* fix ignore patterns
