[Vulcan] Fix numeric symmetric nickname delimiters

CHANGELOG.md

@@ -9,6 +9,7 @@ adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 ### Fixed
 
 - Surname particles remain attached after given-name initials: `J. van Gogh` now keeps first name `J.` and surname `van Gogh`, rather than promoting `van` to the first name. This also applies with a salutation, nickname, or trailing credential. See the [parser regression cases](tests/InitialSurnamePrefixTest.php).
+- Numeric symmetric nickname delimiters now obey token boundaries when splitting names and shield nickname commas during standalone confidence assessment.
 
 ## [1.6.0] - 2026-10-16
 

src/Confidence.php

@@ -284,6 +284,7 @@ private static function tokenizeAsciiDelimiters(string $normalized, array $delim
 
             $closerStart = $position - 1;
             foreach ($symmetric as $delimiter => $_) {
+                $delimiter = (string) $delimiter;
                 if ($closerStart < $tokenStart || $normalized[$closerStart] !== $delimiter) {
                     continue;
                 }

src/StructuralCommaSplitter.php

@@ -115,6 +115,7 @@ private static function splitDelimiters(array $delimiters): array
         /** @var array<string, true> $symmetric */
         $symmetric = [];
         foreach ($delimiters as $open => $close) {
+            $open = (string) $open;
             if ($open === '' || $close === '') {
                 continue;
             }

tests/ConfidenceTest.php

@@ -306,6 +306,45 @@ public function testEmptyWhitespacePreservesTabsBeforeConfidenceTokenization():
         );
     }
 
+    /**
+     * @return array<string, array{string}>
+     */
+    public static function numericNicknameDelimiterProvider(): array
+    {
+        $cases = [];
+        for ($digit = 0; $digit <= 9; ++$digit) {
+            $cases['digit ' . $digit] = [(string) $digit];
+        }
+
+        return $cases;
+    }
+
+    #[DataProvider('numericNicknameDelimiterProvider')]
+    public function testNumericNicknameDelimitersShieldCommas(string $delimiter): void
+    {
+        $delimiters = [$delimiter => $delimiter];
+        $input = 'John ' . $delimiter . 'foo,do,bar' . $delimiter . ' Smith';
+        $name = (new Parser())->setNicknameDelimiters($delimiters)->parse($input);
+
+        $this->assertSame('Foo,Do,Bar', $name->getNickname());
+        $this->assertSame(['ambiguous' => false, 'notes' => []], $name->getConfidence());
+        $this->assertSame(
+            $name->getConfidence(),
+            Confidence::assess($input, nicknameDelimiters: $delimiters),
+        );
+
+        // The comma after the closed nickname must remain structural.
+        $this->assertTrue(Confidence::assess(
+            $input . ', do',
+            nicknameDelimiters: $delimiters,
+        )['ambiguous']);
+        // An unmatched opener must not hide the lowercase credential.
+        $this->assertTrue(Confidence::assess(
+            'John ' . $delimiter . 'foo,do,bar Smith',
+            nicknameDelimiters: $delimiters,
+        )['ambiguous']);
+    }
+
     public function testManyConfiguredDelimitersStayWithinMemoryBudget(): void
     {
         $input = 'X ' . str_repeat('a', (1024 * 1024) - 10) . ', Y';

tests/NumericNicknameDelimiterTest.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace Tests\Iliaal\NameParser;
+
+use Iliaal\NameParser\Parser;
+use Iliaal\NameParser\StructuralCommaSplitter;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+
+class NumericNicknameDelimiterTest extends TestCase
+{
+    /**
+     * @return array<string, array{string}>
+     */
+    public static function delimiterProvider(): array
+    {
+        $cases = [];
+        foreach (['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '-1'] as $delimiter) {
+            $cases['delimiter ' . $delimiter] = [$delimiter];
+        }
+
+        return $cases;
+    }
+
+    #[DataProvider('delimiterProvider')]
+    public function testSymmetricNumericDelimitersRequireTokenBoundaries(string $delimiter): void
+    {
+        $delimiters = [$delimiter => $delimiter];
+        $input = 'Smith' . $delimiter . ', John' . $delimiter;
+
+        $this->assertSame(
+            ['Smith' . $delimiter, ' John' . $delimiter],
+            StructuralCommaSplitter::split($input, $delimiters),
+        );
+        $name = (new Parser())->setNicknameDelimiters($delimiters)->parse($input);
+        $this->assertSame('John' . $delimiter, $name->getFirstname());
+        $this->assertSame('Smith' . $delimiter, $name->getLastname());
+        $this->assertSame('', $name->getNickname());
+
+        $this->assertSame(
+            ['John ' . $delimiter . 'foo', 'bar' . $delimiter . 'x Smith'],
+            StructuralCommaSplitter::split('John ' . $delimiter . 'foo,bar' . $delimiter . 'x Smith', $delimiters),
+        );
+        $closed = 'John ' . $delimiter . 'foo,bar' . $delimiter . ' Smith';
+        $this->assertSame([$closed], StructuralCommaSplitter::split($closed, $delimiters));
+    }
+}