TASK: Implement MatchParser

Author: grebaldi

src/Language/AST/Node/Match/InvalidMatchArmNodes.php

@@ -0,0 +1,47 @@
+<?php
+
+/**
+ * PackageFactory.ComponentEngine - Universal View Components for PHP
+ *   Copyright (C) 2023 Contributors of PackageFactory.ComponentEngine
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace PackageFactory\ComponentEngine\Language\AST\Node\Match;
+
+use PackageFactory\ComponentEngine\Language\AST\ASTException;
+
+final class InvalidMatchArmNodes extends ASTException
+{
+    public static function becauseTheyWereEmpty(): self
+    {
+        return new self(
+            code: 1691150119,
+            message: 'A match statement must contain at least one match arm.'
+        );
+    }
+
+    public static function becauseTheyContainMoreThanOneDefaultMatchArmNode(
+        MatchArmNode $secondDefaultMatchArmNode
+    ): self
+    {
+        return new self(
+            code: 1691150238,
+            message: 'A match statement must not contain more than one default match arm.',
+            affectedRangeInSource: $secondDefaultMatchArmNode->rangeInSource
+        );
+    }
+}

src/Language/AST/Node/Match/MatchArmNode.php

@@ -29,10 +29,15 @@
 
 final class MatchArmNode extends Node
 {
-    private function __construct(
+    public function __construct(
         public readonly Range $rangeInSource,
         public readonly null | ExpressionNodes $left,
         public readonly ExpressionNode $right
     ) {
     }
+
+    public function isDefault(): bool
+    {
+        return is_null($this->left);
+    }
 }

src/Language/AST/Node/Match/MatchArmNodes.php

@@ -29,8 +29,26 @@ final class MatchArmNodes
      */
     public readonly array $items;
 
+    private ?MatchArmNode $defaultArm = null;
+
     public function __construct(MatchArmNode ...$items)
     {
+        if (count($items) === 0) {
+            throw InvalidMatchArmNodes::becauseTheyWereEmpty();
+        }
+
+        foreach ($items as $item) {
+            if ($item->isDefault()) {
+                if (is_null($this->defaultArm)) {
+                    $this->defaultArm = $item;
+                } else {
+                    throw InvalidMatchArmNodes::becauseTheyContainMoreThanOneDefaultMatchArmNode(
+                        secondDefaultMatchArmNode: $item
+                    );
+                }
+            }
+        }
+
         $this->items = $items;
     }
 }

src/Language/Parser/Expression/ExpressionCouldNotBeParsed.php

@@ -43,4 +43,18 @@ public static function becauseOfUnexpectedToken(
             affectedRangeInSource: $actualToken->boundaries
         );
     }
+
+    public static function becauseOfUnexpectedExceedingToken(
+        Token $exceedingToken
+    ): self {
+        return new self(
+            code: 1691141293,
+            message: sprintf(
+                'Expression could not be parsed because token stream was expected to end, '
+                . 'but continued with %s instead.',
+                $exceedingToken->toDebugString()
+            ),
+            affectedRangeInSource: $exceedingToken->boundaries
+        );
+    }
 }

src/Language/Parser/Expression/ExpressionParser.php

@@ -34,6 +34,7 @@
 use PackageFactory\ComponentEngine\Language\AST\Node\UnaryOperation\UnaryOperator;
 use PackageFactory\ComponentEngine\Language\Parser\BooleanLiteral\BooleanLiteralParser;
 use PackageFactory\ComponentEngine\Language\Parser\IntegerLiteral\IntegerLiteralParser;
+use PackageFactory\ComponentEngine\Language\Parser\Match\MatchParser;
 use PackageFactory\ComponentEngine\Language\Parser\NullLiteral\NullLiteralParser;
 use PackageFactory\ComponentEngine\Language\Parser\StringLiteral\StringLiteralParser;
 use PackageFactory\ComponentEngine\Language\Parser\Tag\TagParser;
@@ -54,6 +55,7 @@ final class ExpressionParser
     private readonly ValueReferenceParser $valueReferenceParser;
     private readonly TemplateLiteralParser $templateLiteralParser;
     private readonly TagParser $tagParser;
+    private readonly MatchParser $matchParser;
 
     public function __construct(
         private ?TokenType $stopAt = null,
@@ -66,6 +68,7 @@ public function __construct(
         $this->valueReferenceParser = new ValueReferenceParser();
         $this->templateLiteralParser = new TemplateLiteralParser();
         $this->tagParser = new TagParser();
+        $this->matchParser = new MatchParser();
     }
 
     /**
@@ -113,7 +116,7 @@ public function parse(\Iterator &$tokens): ExpressionNode
      * @param \Iterator<mixed,Token> $tokens
      * @return ExpressionNode
      */
-    public function parseUnaryStatement(\Iterator &$tokens): ExpressionNode
+    private function parseUnaryStatement(\Iterator &$tokens): ExpressionNode
     {
         $result = match (Scanner::type($tokens)) {
             TokenType::OPERATOR_BOOLEAN_NOT =>
@@ -136,6 +139,8 @@ public function parseUnaryStatement(\Iterator &$tokens): ExpressionNode
                 $this->parseTag($tokens),
             TokenType::TEMPLATE_LITERAL_START =>
                 $this->parseTemplateLiteral($tokens),
+            TokenType::KEYWORD_MATCH =>
+                $this->parseMatch($tokens),
             TokenType::BRACKET_ROUND_OPEN =>
                 $this->parseBracketedExpression($tokens),
             default =>
@@ -152,6 +157,7 @@ public function parseUnaryStatement(\Iterator &$tokens): ExpressionNode
                         TokenType::STRING,
                         TokenType::TAG_START_OPENING,
                         TokenType::TEMPLATE_LITERAL_START,
+                        TokenType::KEYWORD_MATCH,
                         TokenType::BRACKET_ROUND_OPEN
                     ),
                     actualToken: $tokens->current()
@@ -173,7 +179,7 @@ public function parseUnaryStatement(\Iterator &$tokens): ExpressionNode
      * @param \Iterator<mixed,Token> $tokens
      * @return ExpressionNode
      */
-    public function parseUnaryOperation(\Iterator &$tokens): ExpressionNode
+    private function parseUnaryOperation(\Iterator &$tokens): ExpressionNode
     {
         $startingToken = $tokens->current();
 
@@ -353,6 +359,20 @@ private function parseTemplateLiteral(\Iterator &$tokens): ExpressionNode
         );
     }
 
+    /**
+     * @param \Iterator<mixed,Token> $tokens
+     * @return ExpressionNode
+     */
+    private function parseMatch(\Iterator &$tokens): ExpressionNode
+    {
+        $matchNode = $this->matchParser->parse($tokens);
+
+        return new ExpressionNode(
+            rangeInSource: $matchNode->rangeInSource,
+            root: $matchNode
+        );
+    }
+
     /**
      * @param \Iterator<mixed,Token> $tokens
      * @return ExpressionNode

src/Language/Parser/Match/MatchCouldNotBeParsed.php

@@ -0,0 +1,45 @@
+<?php
+
+/**
+ * PackageFactory.ComponentEngine - Universal View Components for PHP
+ *   Copyright (C) 2023 Contributors of PackageFactory.ComponentEngine
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, either version 3 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace PackageFactory\ComponentEngine\Language\Parser\Match;
+
+use PackageFactory\ComponentEngine\Language\AST\Node\Match\InvalidMatchArmNodes;
+use PackageFactory\ComponentEngine\Language\Parser\ParserException;
+use PackageFactory\ComponentEngine\Parser\Source\Range;
+
+final class MatchCouldNotBeParsed extends ParserException
+{
+    public static function becauseOfInvalidMatchArmNodes(
+        InvalidMatchArmNodes $cause,
+        ?Range $affectedRangeInSource = null
+    ): self {
+        return new self(
+            code: 1691152175,
+            message: sprintf(
+                'Match could not be parsed because of invalid match arm nodes: %s.',
+                $cause->getMessage()
+            ),
+            affectedRangeInSource: $affectedRangeInSource ?? $cause->affectedRangeInSource,
+            cause: $cause
+        );
+    }
+}