fix syntax checker failing on constants (#162)

Author: PhilippImhof

classes/local/answer_parser.php

@@ -246,8 +246,8 @@ private function is_acceptable_algebraic_formula(bool $fornumericalformula = fal
         ];
         $operatorwhitelist = ['+', '_', '-', '/', '*', '**', '^', '%'];
         foreach ($answertokens as $token) {
-            // Cut short, if it is a NUMBER token.
-            if ($token->type === token::NUMBER) {
+            // Cut short, if it is a NUMBER or CONSTANT token.
+            if (in_array($token->type, [token::NUMBER, token::CONSTANT])) {
                 continue;
             }
             if ($token->type === token::VARIABLE) {
@@ -310,7 +310,7 @@ private function is_valid_syntax(): bool {
         // should be only one single element on the stack.
         $stack = [];
         foreach ($tokens as $token) {
-            if (in_array($token->type, [token::STRING, token::NUMBER, token::VARIABLE])) {
+            if (in_array($token->type, [token::STRING, token::NUMBER, token::VARIABLE, token::CONSTANT])) {
                 $stack[] = $token->value;
             }
             if ($token->type === token::OPERATOR) {

tests/answer_parser_test.php

@@ -98,6 +98,9 @@ public static function provide_algebraic_formulas(): array {
             [qtype_formulas::ANSWER_TYPE_NUMBER, 'pi'],
             [qtype_formulas::ANSWER_TYPE_NUMERIC, '3e8 4.e8 .5e8'],
             [qtype_formulas::ANSWER_TYPE_NUMERICAL_FORMULA, '- 3'],
+            [qtype_formulas::ANSWER_TYPE_NUMERICAL_FORMULA, 'sin(3)'],
+            [qtype_formulas::ANSWER_TYPE_NUMERICAL_FORMULA, 'sin(pi)'],
+            [qtype_formulas::ANSWER_TYPE_NUMERICAL_FORMULA, 'sin(π)'],
             [qtype_formulas::ANSWER_TYPE_NUMERICAL_FORMULA, 'sin(3)-3+exp(4)'],
             [qtype_formulas::ANSWER_TYPE_NUMERICAL_FORMULA, '3+exp(4+5)^sin(6+7)'],
             [qtype_formulas::ANSWER_TYPE_NUMERICAL_FORMULA, '3+4^-(9)'],

version.php

@@ -25,16 +25,16 @@
 defined('MOODLE_INTERNAL') || die();
 
 $plugin->component = 'qtype_formulas';
-$plugin->version = 2024100701;
+$plugin->version = 2025021400;
 
 $plugin->cron = 0;
-$plugin->requires = 2017111300;
-$plugin->dependencies = array(
+$plugin->requires = 2022112800;
+$plugin->dependencies = [
     'qbehaviour_adaptive' => 2015111600,
     'qbehaviour_adaptivemultipart' => 2014092500,
     'qtype_multichoice' => 2015111600,
-);
-$plugin->supported = [39, 405];
-$plugin->release = '5.3.4.post0 for Moodle 3.9+';
+];
+$plugin->supported = [401, 405];
+$plugin->release = '6.0.0dev';
 
-$plugin->maturity = MATURITY_STABLE;
+$plugin->maturity = MATURITY_RC;