you can replace "grep { !member($_, ...) } @l" with "difference2([ @l ], [ ... ])"

2 files changed, 10 insertions, 1 deletions

diff --git a/perl_checker.src/parser_helper.ml b/perl_checker.src/parser_helper.ml
index 3700f2f..8d238ed 100644
--- a/perl_checker.src/parser_helper.ml
+++ b/perl_checker.src/parser_helper.ml
@@ -883,7 +883,14 @@ let call_raw force_non_builtin_func (e, para) =
 						      warn_rule "you can replace \"map { if_(..., $_) }\" with \"grep { ... }\""
 	  | _ -> check_anonymous_block f para)
 
-      | "grep"
+      | "grep" ->
+	  (match para with
+	  | [ Anonymous_sub(None, Block [ List [ Call_op("not", [ Call(Deref(I_func, Ident(None, "member", _)), [ List(Deref(I_scalar, Ident(None, "_", _)) :: _) ]) ], _) ] ], _); _ ] ->
+	      warn_rule "you can replace \"grep { !member($_, ...) } @l\" with \"difference2([ @l ], [ ... ])\""
+	  | [ Anonymous_sub(None, Block [ List [ Call(Deref(I_func, Ident(None, "member", _)), [ List(Deref(I_scalar, Ident(None, "_", _)) :: _) ]) ] ], _); _ ] ->
+	      warn_rule "you can replace \"grep { member($_, ...) } @l\" with \"intersection([ @l ], [ ... ])\""
+	  | _ -> check_anonymous_block f para)
+
       | "grep_index" | "map_index" | "partition" | "uniq_"
       | "find"
       | "any" | "every"
diff --git a/perl_checker.src/test/suggest_better.t b/perl_checker.src/test/suggest_better.t
index be238a2..d3af927 100644
--- a/perl_checker.src/test/suggest_better.t
+++ b/perl_checker.src/test/suggest_better.t
@@ -72,6 +72,8 @@ member($xxx, keys %h)                    you can replace "member($xxx, keys %yyy
 
 !($xxx eq 'foo')                         !($foo eq $bar) is better written $foo ne $bar
 
+grep { !member($_, qw(a b c)) } @l       you can replace "grep { !member($_, ...) } @l" with "difference2([ @l ], [ ... ])"
+
 foreach (@l) {                           use "push @l2, grep { ... } ..." instead of "foreach (...) { push @l2, $_ if ... }"
   push @l2, $_ if yyy($_);                 or sometimes "@l2 = grep { ... } ..."
 }