*** empty log message ***

4 files changed, 20 insertions, 6 deletions

diff --git a/perl_checker.src/common.ml b/perl_checker.src/common.ml
index a4d0789..07e138e 100644
--- a/perl_checker.src/common.ml
+++ b/perl_checker.src/common.ml
@@ -715,6 +715,10 @@ let char_is_alpha c =
   Char.code 'a' <= i && i <= Char.code 'z' ||
   Char.code 'A' <= i && i <= Char.code 'Z'
 
+let char_is_number c =
+  let i = Char.code c in
+  Char.code '0' <= i && i <= Char.code '9'
+
 let rec string_forall_with f i s =
   try
     f s.[i] && string_forall_with f (i+1) s
diff --git a/perl_checker.src/common.mli b/perl_checker.src/common.mli
index cfb4780..ee2bb01 100644
--- a/perl_checker.src/common.mli
+++ b/perl_checker.src/common.mli
@@ -193,6 +193,7 @@ val is_lowercase : char -> bool
 val char_is_alphanumerical : char -> bool
 val char_is_alphanumerical_ : char -> bool
 val char_is_alpha : char -> bool
+val char_is_number : char -> bool
 val string_forall_with : (char -> bool) -> int -> string -> bool
 val starts_with_non_lowercase : string -> bool
 val fold_lines : ('a -> string -> 'a) -> 'a -> in_channel -> 'a
diff --git a/perl_checker.src/parser.mly b/perl_checker.src/parser.mly
index 7d7948a..695e88a 100644
--- a/perl_checker.src/parser.mly
+++ b/perl_checker.src/parser.mly
@@ -220,8 +220,8 @@ term:
 
 
 | term PATTERN_MATCH     PATTERN   {sp_n($2); sp_p($3); check_unneeded_var_dollar_   ($1); to_Call_op_(P_expr, "m//",  sndfst $1 :: from_PATTERN $3) (sp_pos_range $1 $3)}
-| term PATTERN_MATCH_NOT PATTERN   {sp_n($2); sp_p($3); check_unneeded_var_dollar_s  ($1); to_Call_op_(P_expr, "!m//", sndfst $1 :: from_PATTERN $3) (sp_pos_range $1 $3)}
-| term PATTERN_MATCH PATTERN_SUBST {sp_n($2); sp_p($3); check_unneeded_var_dollar_not($1); to_Call_op_(P_expr, "s///", sndfst $1 :: from_PATTERN_SUBST $3) (sp_pos_range $1 $3)}
+| term PATTERN_MATCH_NOT PATTERN   {sp_n($2); sp_p($3); check_unneeded_var_dollar_not($1); to_Call_op_(P_expr, "!m//", sndfst $1 :: from_PATTERN $3) (sp_pos_range $1 $3)}
+| term PATTERN_MATCH PATTERN_SUBST {sp_n($2); sp_p($3); check_unneeded_var_dollar_s  ($1); to_Call_op_(P_expr, "s///", sndfst $1 :: from_PATTERN_SUBST $3) (sp_pos_range $1 $3)}
 | term PATTERN_MATCH_NOT PATTERN_SUBST {die_with_rawpos (sndsnd $2) "use =~ instead of !~ and negate the return value"}
 
 | term PATTERN_MATCH     scalar { (P_expr, Too_complex), sp_pos_range $1 $3}
diff --git a/perl_checker.src/parser_helper.ml b/perl_checker.src/parser_helper.ml
index d377109..1e03f0e 100644
--- a/perl_checker.src/parser_helper.ml
+++ b/perl_checker.src/parser_helper.ml
@@ -14,10 +14,13 @@ let var_STDOUT = Deref(I_star, Ident(None, "STDOUT", raw_pos2pos bpos))
 let is_var_dollar_ = function
   | Deref(I_scalar, Ident(None, "_", _)) -> true
   | _ -> false
+let is_var_number_match = function
+  | Deref(I_scalar, Ident(None, s, _)) -> String.length s = 1 && char_is_number s.[0]
+  | _ -> false
 
 let is_parenthesized = function
   | List[]
-  | List[List[_]] -> true
+  | List[List _] -> true
   | _ -> false
 
 let un_parenthesize = function
@@ -276,9 +279,15 @@ let check_arrow_needed ((_, e), _) ter =
   | Deref_with _ -> warn (sndsnd ter) "the arrow \"->\" is unneeded"
   | _ -> ()
 
-let check_unneeded_var_dollar_    ((_, e), (_, pos)) = if is_var_dollar_ e then warn pos "\"$_ =~ /regexp/\" can be written \"/regexp/\""
-let check_unneeded_var_dollar_s   ((_, e), (_, pos)) = if is_var_dollar_ e then warn pos "\"$_ =~ s/regexp/.../\" can be written \"s/regexp/.../\""
-let check_unneeded_var_dollar_not ((_, e), (_, pos)) = if is_var_dollar_ e then warn pos "\"$_ !~ /regexp/\" can be written \"!/regexp/\""
+let check_unneeded_var_dollar_    ((_, e), (_, pos)) =
+  if is_var_dollar_ e then warn pos "\"$_ =~ /regexp/\" can be written \"/regexp/\"" else
+  if is_var_number_match e then warn pos "do not use the result of a match (eg: $1) to match another pattern"
+let check_unneeded_var_dollar_not ((_, e), (_, pos)) =
+  if is_var_dollar_ e then warn pos "\"$_ !~ /regexp/\" can be written \"!/regexp/\"" else
+  if is_var_number_match e then warn pos "do not use the result of a match (eg: $1) to match another pattern"
+let check_unneeded_var_dollar_s   ((_, e), (_, pos)) = 
+  if is_var_dollar_ e then warn pos "\"$_ =~ s/regexp/.../\" can be written \"s/regexp/.../\"" else
+  if is_var_number_match e then die_with_rawpos pos "do not modify the result of a match (eg: $1)"
 
 let check_MULT_is_x (s, _) = if s <> "x" then die_rule "syntax error"
 let check_my (s, _) = if s <> "my" then die_rule "syntax error"