diff options
| author | Peter Mikkelsen <peter@pmikkelsen.com> | 2021-07-22 17:35:34 +0000 |
|---|---|---|
| committer | Peter Mikkelsen <peter@pmikkelsen.com> | 2021-07-22 17:35:34 +0000 |
| commit | 463f3b41ac6a17f6fe88f6c114aa849876bfcf4e (patch) | |
| tree | 7790cdc3692beb8b1e5c972822736cdd77b1ba13 | |
| parent | 0cf3816c9419954317fd54da5a063615402bf1d1 (diff) | |
Warn about singleton variables in clauses, as it is often a sign of a mis-spelling
| -rw-r--r-- | loader.pl | 44 |
1 files changed, 34 insertions, 10 deletions
@@ -19,17 +19,18 @@ load_module_from_file(File) :- close(Stream). read_and_handle_terms(Stream, Module0, Module) :- - ( read_one_term(Stream, Term) - -> handle_term(Term, Module0, Module1), + ( read_one_term(Stream, Term, Singles) + -> handle_term(Term, Singles, Module0, Module1), read_and_handle_terms(Stream, Module1, Module) ; Module = Module0 ). -read_one_term(Stream, Term) :- +read_one_term(Stream, Term, Singles) :- consume_whitespace(Stream), peek_char(Stream, NextCh), NextCh \= end_of_file, - read_term(Stream, Term, []). + read_term(Stream, Term, [singletons(Singletons)]), + singleton_names(Singletons, Singles). whitespace(' '). whitespace(' '). @@ -43,19 +44,33 @@ consume_whitespace(S) :- ; true ). -handle_term(:- Directive, Module, NewModule) :- +singleton_names([], []). +singleton_names([Name = _|Rest0], Names) :- + singleton_names(Rest0, Rest), + ( atom_concat('_', _, Name) + -> Names = Rest + ; Names = [Name|Rest] + ). + +handle_term(:- Directive, _, Module, NewModule) :- !, handle_directive(Directive, Module, NewModule). -handle_term(Head :- Body, Module, Module) :- +handle_term(Head :- Body, Singles, Module, Module) :- !, - Module:assertz(Head :- Body). -handle_term(Head --> Body, Module, Module) :- + handle_clause(Head, Body, Singles, Module). +handle_term(Head --> Body, Singles, Module, Module) :- !, write('DCG RULE: '), write(Head --> Body), nl. -handle_term(Head, Module, Module) :- - Module:assertz(Head). +handle_term(Head, Singles, Module, Module) :- + handle_clause(Head, true, Singles, Module). + +handle_clause(Head, Body, Singletons, Module) :- + functor(Head, Name, Arity), + PredicateIndicator = Name / Arity, + warn_singletons(PredicateIndicator, Singletons), + Module:assertz(Head :- Body). handle_directive(op(Priority, Specifier, Operator), Module, Module) :- Module:op(Priority, Specifier, Operator). @@ -74,6 +89,15 @@ handle_directive(D, Module, Module) :- write(D), nl. +warn_singletons(_, []). +warn_singletons(PI, Singles) :- + write('Warning: singleton variables in '), + write(PI), + write(': '), + write(Singles), + write('.'), + nl. + ensure_loads(_) :- fail. ensure_load(F) :- |