added support for variable tags <{$foo}>

src/Latte/Compiler/TemplateLexer.php

@@ -128,9 +128,9 @@ private function stateHtmlText(): \Generator
 		yield from $this->match('~(?J)
 			(?<Text>.+?)??
 			(
-				(?<Indentation>(?<=\n|^)[ \t]+)?(?<Html_TagOpen><)(?<Slash>/)?(?<Html_Name>' . self::ReTagName . ')|  # <tag </tag
+				(?<Indentation>(?<=\n|^)[ \t]+)?(?<Html_TagOpen><)(?<Slash>/)?(?=[a-z]|' . $this->openDelimiter . ')|  # < </ tag
 				(?<Html_CommentOpen><!--(?!>|->))|                                                      # <!-- comment
-				(?<Html_BogusOpen><[/?!])|                                                              # <!doctype <?xml or error
+				(?<Html_BogusOpen><[?!])|                                                               # <!doctype <?xml or error
 				(?<Indentation>(?<=\n|^)[ \t]+)?(?<Latte_TagOpen>' . $this->openDelimiter . '(?!\*))|   # {tag
 				(?<Indentation>(?<=\n|^)[ \t]+)?(?<Latte_CommentOpen>' . $this->openDelimiter . '\*)|   # {* comment
 				$

src/Latte/Compiler/TemplateParserHtml.php

@@ -82,11 +82,13 @@ private function parseTag(): ?Node
 			return $this->parseElement();
 		}
 
-		$name = $stream->peek(2)->text ?? '';
+		$name = $stream->peek(2);
 		if ($this->element
 			&& $this->parser->peekTag() === $this->element->data->tag
-			&& (strcasecmp($name, $this->element->name) === 0
-				|| !in_array($name, $this->element->data->unclosedTags ?? [], true))
+			&& ($name?->is(Token::Latte_TagOpen)
+				|| ($name?->is(Token::Html_Name)
+					&& (strcasecmp($name->text, $this->element->name) === 0
+						|| !in_array($name->text, $this->element->data->unclosedTags ?? [], true))))
 		) {
 			return null; // go to parseElement() one level up
 		}
@@ -122,17 +124,20 @@ private function parseElement(): Node
 
 			if ($stream->is(Token::Html_TagOpen) && $stream->peek(1)->is(Token::Slash)
 				&& ($endName = $stream->peek(2))
-				&& strcasecmp($elem->name, $endName->text) === 0
+				&& (($endName->is(Token::Html_Name) && (strcasecmp($elem->name, $endName->text) === 0))
+					|| ($endName->is(Token::Latte_TagOpen) && $elem->variableName))
 			) {
 				$elem->content = $content;
 				$elem->content->append($this->extractIndentation());
 				$this->parseElementEndTag();
 
 			} elseif ($outerNodes || $innerNodes || $tagNodes
+				|| $elem->variableName
 				|| ($this->parser->getContentType() === ContentType::Html && in_array(strtolower($elem->name), ['script', 'style'], true))
 			) {
+				$elemName = $elem->variableName ? '{...}' : $elem->name;
 				$stream->throwUnexpectedException(
-					addendum: ", expecting </{$elem->name}> for element started " . $elem->position->toWords(),
+					addendum: ", expecting </{$elemName}> for element started " . $elem->position->toWords(),
 					excerpt: isset($endName) ? "/{$endName->text}>" : '',
 				);
 			} else { // element collapsed to tags
@@ -172,10 +177,21 @@ private function parseStartTag(&$elem = null): Html\ElementNode
 		$stream = $this->parser->getStream();
 		$openToken = $stream->consume(Token::Html_TagOpen);
 		$this->parser->getLexer()->setState(TemplateLexer::StateHtmlTag);
-		$name = $stream->consume(Token::Html_Name)->text;
+
+		if ($stream->is(Token::Latte_TagOpen)) {
+			$name = '';
+			$variableName = $this->parser->parseLatteStatement();
+			if (!$variableName instanceof Latte\Essential\Nodes\PrintNode) {
+				throw new CompileException('Only expression can be used as a HTML tag name.', $variableName->position);
+			}
+		} else {
+			$name = $stream->consume(Token::Html_Name)->text;
+			$variableName = null;
+		}
 		if (!$stream->is(Token::Whitespace, Token::Slash, Token::Html_TagClose)) {
 			throw $stream->throwUnexpectedException();
 		}
+
 		$this->parser->lastIndentation = null;
 		$this->parser->inHead = false;
 		$elem = new Html\ElementNode(
@@ -186,6 +202,7 @@ private function parseStartTag(&$elem = null): Html\ElementNode
 		);
 		$elem->attributes = $this->parser->parseFragment([$this, 'inTagResolve']);
 		$elem->selfClosing = (bool) $stream->tryConsume(Token::Slash);
+		$elem->variableName = $variableName?->expression;
 		$stream->consume(Token::Html_TagClose);
 		$state = !$elem->selfClosing && $this->parser->getContentType() === ContentType::Html && in_array(strtolower($name), ['script', 'style'], true)
 			? TemplateLexer::StateHtmlRawText
@@ -224,7 +241,14 @@ private function parseElementEndTag(): void
 		$stream->consume(Token::Html_TagOpen);
 		$this->parser->getLexer()->setState(TemplateLexer::StateHtmlTag);
 		$stream->consume(Token::Slash);
-		$stream->consume(Token::Html_Name);
+		if ($stream->is(Token::Latte_TagOpen)) {
+			$node = $this->parser->parseLatteStatement();
+			if (!$node instanceof Latte\Essential\Nodes\PrintNode) {
+				throw new CompileException('Only expression can be used as a HTML tag name.', $node->position);
+			}
+		} else {
+			$stream->consume(Token::Html_Name);
+		}
 		$stream->tryConsume(Token::Whitespace);
 		$stream->consume(Token::Html_TagClose);
 		$this->parser->getLexer()->setState(TemplateLexer::StateHtmlText);

tests/common/Compiler.errors.phpt

@@ -68,6 +68,42 @@ Assert::exception(
 	'Attribute n:href must not appear inside {tags} (on line 1 at column 8)',
 );
 
+Assert::exception(
+	fn() => $latte->compile('<{if 1}{/if}>'),
+	Latte\CompileException::class,
+	'Only expression can be used as a HTML tag name (on line 1 at column 2)',
+);
+
+Assert::exception(
+	fn() => $latte->compile('<{$foo}>'),
+	Latte\CompileException::class,
+	'Unexpected end, expecting </{...}> for element started on line 1 at column 1 (on line 1 at column 9)',
+);
+
+Assert::exception(
+	fn() => $latte->compile('<{$foo}>...</{if 1}{/if}>'),
+	Latte\CompileException::class,
+	'Only expression can be used as a HTML tag name (on line 1 at column 14)',
+);
+
+Assert::exception(
+	fn() => $latte->compile('<a>...</{$foo}>'),
+	Latte\CompileException::class,
+	"Unexpected '{', expecting HTML name (on line 1 at column 9)",
+);
+
+Assert::exception(
+	fn() => $latte->compile('<{$foo}></span></{$foo}>'),
+	Latte\CompileException::class,
+	"Unexpected '</span>', expecting </{...}> for element started on line 1 at column 1 (on line 1 at column 9)",
+);
+
+Assert::exception(
+	fn() => $latte->compile('</{$foo}>'), // bogus tag
+	Latte\CompileException::class,
+	"Unexpected '{', expecting HTML name (on line 1 at column 3)",
+);
+
 Assert::exception(
 	fn() => $latte->compile('<span{$foo}>'),
 	Latte\CompileException::class,

tests/common/Compiler.variableTags.phpt

@@ -0,0 +1,36 @@
+<?php
+
+/**
+ * Test: variable tag names
+ */
+
+declare(strict_types=1);
+
+use Tester\Assert;
+
+require __DIR__ . '/../bootstrap.php';
+
+
+$latte = new Latte\Engine;
+$latte->setLoader(new Latte\Loaders\StringLoader);
+
+$template = <<<'EOD'
+	{var $tag = 'foo'}
+
+	<{$tag}>...</{$tag}>
+
+	<{$tag}><span></{$tag}>
+
+	<{$tag}>...</{$foo}> {* not checked *}
+
+	<{=a}><{=b}>...</{=x}></{=y}> {* not checked *}
+	EOD;
+
+Assert::matchFile(
+	__DIR__ . '/expected/Compiler.variable.tags.php',
+	$latte->compile($template),
+);
+Assert::matchFile(
+	__DIR__ . '/expected/Compiler.variable.tags.html',
+	$latte->renderToString($template, ['x' => '\' & "']),
+);

tests/common/expected/Compiler.variable.tags.html

@@ -0,0 +1,8 @@
+
+<foo>...</foo>
+
+<foo><span></foo>
+
+<foo>...</foo>
+
+<a><b>...</b></a>

tests/common/expected/Compiler.variable.tags.php

@@ -0,0 +1,52 @@
+<?php
+%A%
+final class Template%a% extends Latte\Runtime\Template
+{
+
+	public function main(array $ʟ_args): void
+	{
+%A%
+		echo "\n";
+		$ʟ_tag[0] = '';
+		echo '<';
+		echo $ʟ_tmp = LR\Filters::safeTag($tag);
+		$ʟ_tag[0] = '</' . $ʟ_tmp . '>' . $ʟ_tag[0];
+		echo '>...';
+		echo $ʟ_tag[0];
+		echo '
+
+';
+		$ʟ_tag[1] = '';
+		echo '<';
+		echo $ʟ_tmp = LR\Filters::safeTag($tag);
+		$ʟ_tag[1] = '</' . $ʟ_tmp . '>' . $ʟ_tag[1];
+		echo '><span>';
+		echo $ʟ_tag[1];
+		echo '
+
+';
+		$ʟ_tag[2] = '';
+		echo '<';
+		echo $ʟ_tmp = LR\Filters::safeTag($tag);
+		$ʟ_tag[2] = '</' . $ʟ_tmp . '>' . $ʟ_tag[2];
+		echo '>...';
+		echo $ʟ_tag[2];
+		echo '
+
+';
+		$ʟ_tag[3] = '';
+		echo '<';
+		echo $ʟ_tmp = LR\Filters::safeTag('a');
+		$ʟ_tag[3] = '</' . $ʟ_tmp . '>' . $ʟ_tag[3];
+		echo '>';
+		$ʟ_tag[4] = '';
+		echo '<';
+		echo $ʟ_tmp = LR\Filters::safeTag('b');
+		$ʟ_tag[4] = '</' . $ʟ_tmp . '>' . $ʟ_tag[4];
+		echo '>...';
+		echo $ʟ_tag[4];
+		echo $ʟ_tag[3];
+		echo ' ';
+	}
+%A%
+}