--- loncom/homework/math_parser/Parser.pm	2015/06/29 15:42:13	1.1
+++ loncom/homework/math_parser/Parser.pm	2015/06/30 17:42:14	1.2
@@ -39,10 +39,16 @@ use aliased 'Apache::math_parser::Tokeni
 # @optional {boolean} unit_mode - handle only numerical expressions with units (no variable)
 ##
 sub new {
-    my $class = shift;
+    my ($class, $implicit_operators, $unit_mode) = @_;
+    if (!defined $implicit_operators) {
+        $implicit_operators = 0;
+    }
+    if (!defined $unit_mode) {
+        $unit_mode = 0;
+    }
     my $self = {
-        _implicit_operators => shift // 0,
-        _unit_mode => shift // 0,
+        _implicit_operators => $implicit_operators,
+        _unit_mode => $unit_mode,
         _defs => Definitions->new(),
     };
     $self->{_defs}->define();
@@ -200,18 +206,18 @@ sub addHiddenOperators {
                 ($token_type == Token->NAME && $next_token_type == Token->NAME) ||
                 ($token_type == Token->NUMBER && $next_token_type == Token->NAME) ||
                 ($token_type == Token->NUMBER && $next_token_type == Token->NUMBER) ||
-                ($token_type == Token->NUMBER && $next_token_value ~~ ["(","[","{"]) ||
+                ($token_type == Token->NUMBER && string_in_array(["(","[","{"], $next_token_value)) ||
                 # ($token_type == Token->NAME && $next_token_value eq "(") ||
                 # name ( could be a function call
-                ($token_value ~~ [")","]","}"] && $next_token_type == Token->NAME) ||
-                ($token_value ~~ [")","]","}"] && $next_token_type == Token->NUMBER) ||
-                ($token_value ~~ [")","]","}"] && $next_token_value eq "(")
+                (string_in_array([")","]","}"], $token_value) && $next_token_type == Token->NAME) ||
+                (string_in_array([")","]","}"], $token_value) && $next_token_type == Token->NUMBER) ||
+                (string_in_array([")","]","}"], $token_value) && $next_token_value eq "(")
            ) {
             # support for things like "(1/2) (m/s)" is complex...
             my $units = ($self->unit_mode && !$in_units &&
-                ($token_type == Token->NUMBER || $token_value ~~ [")","]","}"]) &&
+                ($token_type == Token->NUMBER || string_in_array([")","]","}"], $token_value)) &&
                 ($next_token_type == Token->NAME ||
-                    ($next_token_value ~~ ["(","[","{"] && scalar(@{$self->tokens}) > $i + 2 &&
+                    (string_in_array(["(","[","{"], $next_token_value) && scalar(@{$self->tokens}) > $i + 2 &&
                     $self->tokens->[$i + 2]->type == Token->NAME)));
             if ($units) {
                 my( $test_token, $index_test);
@@ -276,5 +282,21 @@ sub parse {
     return $root;
 }
 
+##
+# Tests if a string is in an array (using eq) (to avoid using $value ~~ @array)
+# @param {Array<string>} array - reference to the array of strings
+# @param {string} value - the string to look for
+# @returns 1 if found, 0 otherwise
+##
+sub string_in_array {
+  my ($array, $value) = @_;
+  foreach my $v (@{$array}) {
+    if ($v eq $value) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
 1;
 __END__