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yap-6.3/pl/checker.yap
Vitor Santos Costa 2d55f41ef6 docs
2018-06-05 11:20:39 +01:00

173 lines
4.7 KiB
Prolog

/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: checker.yap *
* comments: style checker for Prolog *
* *
* Last rev: $Date: 2008-03-31 22:56:22 $,$Author: vsc $ *
* *
*************************************************************************/
:- system_module( style_checker, [no_style_check/1,
style_check/1], ['$check_term'/5,
'$sv_warning'/2,
'$syntax_check_discontiguous'/2,
'$syntax_check_multiple'/2,
'$syntax_check_single_var'/2]).
/**
@defgroup YAPStyle Checker
@ingroup YAPCompilerSettings
@{
YAP implements a style-checker thay currently verifies whether:
1 named variables occur once in a clause.
2 clauses from dofferent predicates are mixed together.
3 clauses for the same predicate occur in different files.
One can declare a predicate to be discontiguous (see the
discontiguous/1 declaration) and/or multifile/1.
*/
/*
@pred style_check(+ _X_)
Turns on style checking according to the attribute specified by _X_,
which must be one of the following:
+ single_var
Checks single occurrences of named variables in a clause.
+ discontiguous
Checks non-contiguous clauses for the same predicate in a file.
+ multiple
Checks the presence of clauses for the same predicate in more than one
file when the predicate has not been declared as `multifile`
+ all
Performs style checking for all the cases mentioned above.
By default, style checking is disabled in YAP unless we are in
`sicstus` or `iso` language mode.
The style_check/1 built-in is now deprecated. Please use
`set_prolog_flag/1` instead.
**/
%
% A Small style checker for YAP
style_check(V) :- var(V), !, fail.
style_check(V) :-
\+atom(V),
\+ is_list(V),
V \= + _,
V \= - _, !,
'$do_error'( type_error('+|-|?(Flag)', V), style_check(V) ).
style_check(V) :-
\+atom(V),
\+ is_list(V),
V \= + _,
V \= + _, !,
'$do_error'( domain_error(style_name, V), style_check(V) ).
style_check(all) :-
style_check( [ singleton, discontiguous, multiple ] ).
style_check(+X) :-
style_check(X).
style_check(single_var) :-
style_check( singleton ).
style_check(singleton) :-
yap_flag( single_var_warnings, true ).
style_check(-single_var) :-
yap_flag( single_var_warnings, false ).
style_check(-singleton) :-
yap_flag( single_var_warnings, false ).
style_check(discontiguous) :-
yap_flag( discontiguous_warnings, true ).
style_check(-discontiguous) :-
yap_flag( discontiguous_warnings, false ).
style_check(multiple) :-
yap_flag( redefine_warnings, true ).
style_check(-multiple) :-
yap_flag( redefine_warnings, false ).
style_check(no_effect).
style_check(+no_effect) .
style_check(-no_effect).
style_check(var_branches).
style_check(+var_branches) :-
'$style_checker'( [ var_branches ] ).
style_check(-var_branches) :-
'$style_checker'( [ -var_branches ] ).
style_check(atom).
style_check(+atom) :-
'$style_checker'( [ atom ] ).
style_check(-atom) :-
'$style_checker'( [ -atom ] ).
style_check(charset) :-
'$style_checker'( [ charset ] ).
style_check(+charset) :-
'$style_checker'( [ charset ] ).
style_check(-charset) :-
'$style_checker'( [ -charset ] ).
style_check('?'(Info) ) :-
L = [ singleton, discontiguous, multiple ],
( lists:member(Style, L ) -> Info = +Style ; Info = -Style ).
style_check([]).
style_check([H|T]) :- style_check(H), style_check(T).
/** @pred no_style_check(+ _X_)
Turns off style checking according to the attribute specified by
_X_, which have the same meaning as in style_check/1.
The no_style_check/1 built-in is now deprecated. Please use
`set_prolog_flag/1` instead.
**/
no_style_check(V) :- var(V), !, fail.
no_style_check(all) :-
'$style_checker'( [ -singleton, -discontiguous, -multiple ] ).
no_style_check(-single_var) :-
'$style_checker'( [ -singleton ] ).
no_style_check(-singleton) :-
'$style_checker'( [ -singleton ] ).
no_style_check(-discontiguous) :-
'$style_checker'( [ -discontiguous ] ).
no_style_check(-multiple) :-
'$style_checker'( [ -multiple ] ).
no_style_check([]).
no_style_check([H|T]) :- no_style_check(H), no_style_check(T).
/**
* @pred discontiguous(+ G) is iso, directive
Avoid warnings from the sytax checker.
Declare that the predicate _G_ or list of predicates are discontiguous
procedures, that is, clauses for discontigous procedures may be
separated by clauses from other procedures.
*/
discontiguous(P) :- '$discontiguous'(P).
/*
@}
*/