Merge pull request #1257 from phpDocumentor/fix/enumerated-list

Allow offset on lists

Author: jaapio

packages/guides-restructured-text/src/RestructuredText/Parser/Productions/EnumeratedListRule.php

@@ -27,12 +27,15 @@
 use function ltrim;
 use function mb_strlen;
 use function mb_substr;
+use function ord;
 use function preg_match;
 use function sprintf;
 use function str_ends_with;
 use function str_starts_with;
 use function strlen;
 use function strpos;
+use function strtolower;
+use function strtoupper;
 use function trim;
 
 /**
@@ -119,8 +122,8 @@ public function apply(BlockContext $blockContext, CompoundNode|null $on = null):
         $start = null;
         $orderType = null;
         if (isset($items[0])) {
-            $start = $items[0]->getOrderNumber();
             $orderType = $items[0]->getOrderType();
+            $start = (string) $this->getStartValue($items[0]->getOrderNumber(), $orderType);
         }
 
         return new ListNode($items, true, $start, $orderType);
@@ -245,4 +248,58 @@ private function markerSuffix(string $marker): string
 
         return '';
     }
+
+    private function getStartValue(string|null $firstItemNumber, string|null $orderType): int|null
+    {
+        if ($firstItemNumber === null) {
+            return null;
+        }
+
+        if ($orderType === 'auto_number' . $this->markerSuffix($firstItemNumber)) {
+            return null;
+        }
+
+        if (preg_match('/^\d+$/', $firstItemNumber)) {
+            return (int) $firstItemNumber;
+        }
+
+        if (preg_match('/^' . self::ROMAN_NUMBER . '$/i', $firstItemNumber, $m)) {
+            $roman = strtoupper($m[1]);
+            $map = [
+                'M' => 1000,
+                'CM' => 900,
+                'D' => 500,
+                'CD' => 400,
+                'C' => 100,
+                'XC' => 90,
+                'L' => 50,
+                'XL' => 40,
+                'X' => 10,
+                'IX' => 9,
+                'V' => 5,
+                'IV' => 4,
+                'I' => 1,
+            ];
+
+            $number = 0;
+            $i = 0;
+            while ($i < strlen($roman)) {
+                foreach ($map as $symbol => $value) {
+                    if (str_starts_with(mb_substr($roman, $i), $symbol)) {
+                        $number += $value;
+                        $i += strlen($symbol);
+                        break;
+                    }
+                }
+            }
+
+            return $number;
+        }
+
+        if (preg_match('/^[a-z]$/i', $firstItemNumber)) {
+            return ord(strtolower($firstItemNumber)) - ord('a') + 1;
+        }
+
+        return 1;
+    }
 }

tests/Functional/tests/list-enumerated/list-enumerated.html

@@ -22,13 +22,13 @@
     <li value="2">Second item</li>
 </ol>
 <p>This is an enumerated list using letters:</p>
-<ol start="a" type="a">
-    <li value="a">First</li>
-    <li value="b">Second</li>
-    <li value="c">Third</li>
+<ol start="7" type="a">
+    <li value="g">First</li>
+    <li value="h">Second</li>
+    <li value="i">Third</li>
 </ol>
 <p>This is an roman list using letters:</p>
-<ol start="I" type="i">
+<ol start="1" type="i">
     <li value="I">First</li>
     <li value="II">Second</li>
     <li value="III">Third</li>

tests/Functional/tests/list-enumerated/list-enumerated.rst

@@ -23,9 +23,9 @@ Using right-parenthesis:
 
 This is an enumerated list using letters:
 
-a. First
-b. Second
-c. Third
+g. First
+h. Second
+i. Third
 
 This is an roman list using letters: