Simplify JoinSpec, move ON quoting to render-time preg_replace_callback

Signed-off-by: Simon Mundy <simon.mundy@peptolab.com>

Author: simon-mundy

src/Sql/Part/JoinSpec.php

@@ -4,9 +4,6 @@
 
 namespace PhpDb\Sql\Part;
 
-use PhpDb\Sql\Argument\Identifier;
-use PhpDb\Sql\Argument\Literal;
-use PhpDb\Sql\ArgumentInterface;
 use PhpDb\Sql\Exception;
 use PhpDb\Sql\Expression;
 use PhpDb\Sql\ExpressionInterface;
@@ -19,10 +16,7 @@
 use function is_array;
 use function is_string;
 use function key;
-use function preg_match_all;
 use function sprintf;
-use function strlen;
-use function substr;
 
 /**
  * Normalized join specification.
@@ -31,22 +25,16 @@
  */
 final readonly class JoinSpec
 {
-    private const IDENTIFIER_PATTERN = '/\b(?!(?:AS|AND|OR|BETWEEN)\b)([a-zA-Z_]\w*+(?:\.[a-zA-Z_]\w*+)*)(?!\s*\()/i';
-
     public string|TableIdentifier|Select|ExpressionInterface $table;
     public JoinTableType $tableType;
     public ?string $alias;
     public PredicateInterface|string $on;
     public bool $isExpressionOn;
     public string $type;
-    public array $columns;
 
     /** @var ColumnRef[] Pre-normalized column references */
     public array $columnRefs;
 
-    /** @var ArgumentInterface[]|null Pre-tokenized ON clause (null for expression ON) */
-    public ?array $onTokens;
-
     /** @param array{name: array|string|TableIdentifier, on: PredicateInterface|string, columns: array, type: string} $join */
     public function __construct(array $join)
     {
@@ -76,46 +64,11 @@ public function __construct(array $join)
         $this->on             = $on;
         $this->isExpressionOn = $on instanceof ExpressionInterface;
         $this->type           = $join['type'];
-        $this->columns        = $join['columns'];
 
         $refs = [];
         foreach ($join['columns'] as $key => $column) {
             $refs[] = new ColumnRef($key, $column);
         }
         $this->columnRefs = $refs;
-
-        $this->onTokens = is_string($on) ? self::tokenizeOn($on) : null;
-    }
-
-    /**
-     * Tokenize a string ON clause into Identifier and Literal tokens.
-     * Identifiers are word-like tokens excluding SQL keywords and function calls.
-     *
-     * @return ArgumentInterface[]
-     */
-    private static function tokenizeOn(string $on): array
-    {
-        preg_match_all(self::IDENTIFIER_PATTERN, $on, $matches, PREG_OFFSET_CAPTURE);
-
-        if ($matches[0] === []) {
-            return [new Literal($on)];
-        }
-
-        $tokens = [];
-        $pos    = 0;
-
-        foreach ($matches[0] as [$match, $offset]) {
-            if ($offset > $pos) {
-                $tokens[] = new Literal(substr($on, $pos, $offset - $pos));
-            }
-            $tokens[] = new Identifier($match);
-            $pos      = $offset + strlen($match);
-        }
-
-        if ($pos < strlen($on)) {
-            $tokens[] = new Literal(substr($on, $pos));
-        }
-
-        return $tokens;
     }
 }

src/Sql/Part/Joins.php

@@ -10,7 +10,9 @@
 use PhpDb\Sql\TableIdentifier;
 
 use function count;
+use function explode;
 use function implode;
+use function preg_replace_callback;
 use function spl_object_id;
 
 /**
@@ -22,6 +24,8 @@
  */
 class Joins extends AbstractPart
 {
+    private const IDENTIFIER_PATTERN = '/\b(?!(?:AS|AND|OR|BETWEEN)\b)([a-zA-Z_]\w*+(?:\.[a-zA-Z_]\w*+)*)(?!\s*\()/i';
+
     public ?Join $model = null;
 
     /** @var JoinSpec[] Normalized join specifications, built at join() time */
@@ -44,17 +48,18 @@ public function toSql(SqlProcessor $processor): ?string
             }
         }
 
+        $platform     = $processor->platform;
         $joinSqlParts = [];
 
         foreach ($this->specs as $j => $spec) {
             $joinName = match ($spec->tableType) {
                 JoinTableType::Expression      => $spec->table->getExpression(), // @phpstan-ignore method.nonObject
                 JoinTableType::TableIdentifier => $processor->resolveTable($spec->table),
                 JoinTableType::Select          => '(' . $processor->processSubSelect($spec->table) . ')',
-                JoinTableType::Identifier      => $processor->platform->quoteIdentifier($spec->table),
+                JoinTableType::Identifier      => $platform->quoteIdentifier($spec->table),
             };
             $quotedAlias = $spec->alias !== null
-                ? $processor->platform->quoteIdentifier($spec->alias)
+                ? $platform->quoteIdentifier($spec->alias)
                 : null;
 
             $renderedTable = $processor->renderTable($joinName, $quotedAlias);
@@ -65,7 +70,11 @@ public function toSql(SqlProcessor $processor): ?string
                     'join' . ($j + 1) . 'part'
                 );
             } else {
-                $onClause = $processor->renderIdentifierFragment($spec->onTokens);
+                $onClause = preg_replace_callback(
+                    self::IDENTIFIER_PATTERN,
+                    static fn($m) => $platform->quoteIdentifier(...explode('.', $m[1], 2)),
+                    $spec->on,
+                );
             }
 
             $joinSqlParts[] = "{$spec->type} JOIN {$renderedTable} ON {$onClause}";

src/Sql/Part/SqlProcessor.php

@@ -131,19 +131,6 @@ public function renderExpression(
         return $expression->renderSql($this, $namedParameterPrefix, $paramIndex);
     }
 
-    /**
-     * @param ArgumentInterface[] $tokens
-     */
-    public function renderIdentifierFragment(array $tokens): string
-    {
-        $sql = '';
-        $pi  = 0;
-        foreach ($tokens as $token) {
-            $sql .= $token->render($this, '', $pi);
-        }
-        return $sql;
-    }
-
     public function renderArgument(
         ArgumentInterface $argument,
         string $paramPrefix,