Parse simple expressions

src/Value/CSSFunction.php

@@ -33,6 +33,35 @@ public function __construct($sName, $aArguments, $sSeparator = ',', $iLineNo = 0
         parent::__construct($aArguments, $sSeparator, $iLineNo);
     }
 
+    /**
+     * @param ParserState $oParserState
+     * @param bool $bIgnoreCase
+     *
+     * @return string
+     *
+     * @throws SourceException
+     * @throws UnexpectedEOFException
+     * @throws UnexpectedTokenException
+     */
+    public static function parseName(ParserState $oParserState, $bIgnoreCase = false)
+    {
+        return $oParserState->parseIdentifier($bIgnoreCase);
+    }
+
+    /**
+     * @param ParserState $oParserState
+     *
+     * @return array
+     *
+     * @throws SourceException
+     * @throws UnexpectedEOFException
+     * @throws UnexpectedTokenException
+     */
+    public static function parseArgs(ParserState $oParserState)
+    {
+        return Value::parseValue($oParserState, ['=', ' ', ',']);
+    }
+
     /**
      * @param ParserState $oParserState
      * @param bool $bIgnoreCase
@@ -45,9 +74,9 @@ public function __construct($sName, $aArguments, $sSeparator = ',', $iLineNo = 0
      */
     public static function parse(ParserState $oParserState, $bIgnoreCase = false)
     {
-        $mResult = $oParserState->parseIdentifier($bIgnoreCase);
+        $mResult = self::parseName($oParserState, $bIgnoreCase);
         $oParserState->consume('(');
-        $aArguments = Value::parseValue($oParserState, ['=', ' ', ',']);
+        $aArguments = self::parseArgs($oParserState);
         $mResult = new CSSFunction($mResult, $aArguments, ',', $oParserState->currentLine());
         $oParserState->consume(')');
         return $mResult;

src/Value/Expression.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace Sabberworm\CSS\Value;
+
+use Sabberworm\CSS\OutputFormat;
+use Sabberworm\CSS\Parsing\ParserState;
+
+/**
+ * An `Expression` represents a special kind of value that is comprised of multiple components wrapped in parenthesis.
+ * Examle `height: (vh - 10);`.
+ */
+class Expression extends CSSFunction
+{
+    /**
+     * @param ParserState $oParserState
+     * @param bool $bIgnoreCase
+     *
+     * @return Expression
+     *
+     * @throws SourceException
+     * @throws UnexpectedEOFException
+     * @throws UnexpectedTokenException
+     */
+    public static function parse(ParserState $oParserState, $bIgnoreCase = false)
+    {
+        $oParserState->consume('(');
+        $aArguments = self::parseArgs($oParserState);
+        $mResult = new Expression("", $aArguments, ',', $oParserState->currentLine());
+        $oParserState->consume(')');
+        return $mResult;
+    }
+}

src/Value/Value.php

@@ -155,8 +155,19 @@ public static function parsePrimitiveValue(ParserState $oParserState)
             $oValue = LineName::parse($oParserState);
         } elseif ($oParserState->comes("U+")) {
             $oValue = self::parseUnicodeRangeValue($oParserState);
+        } elseif ($oParserState->comes("(")) {
+            $oValue = Expression::parse($oParserState);
         } else {
-            $oValue = self::parseIdentifierOrFunction($oParserState);
+            $sNextChar = $oParserState->peek(1);
+            try {
+                $oValue = self::parseIdentifierOrFunction($oParserState);
+            } catch (UnexpectedTokenException $e) {
+                if (in_array($sNextChar, ['+', '-', '*', '/'])) {
+                    $oValue = $oParserState->consume(1);
+                } else {
+                    throw $e;
+                }
+            }
         }
         $oParserState->consumeWhiteSpace();
         return $oValue;

tests/ParserTest.php

@@ -512,6 +512,20 @@ public function expandShorthands()
         self::assertSame($sExpected, $oDoc->render());
     }
 
+    /**
+     * @test
+     */
+    public function parseExpressions()
+    {
+        $oDoc = self::parsedStructureForFile('expressions');
+        $sExpected = 'div {height: (vh - 10);}'
+            . "\n"
+            . 'div {height: (vh - 10)/2;}'
+            . "\n"
+            . 'div {height: max(5,(vh - 10));}';
+        self::assertSame($sExpected, $oDoc->render());
+    }
+
     /**
      * @test
      */
@@ -688,8 +702,8 @@ public function calcNestedInFile()
     public function invalidCalcInFile()
     {
         $oDoc = self::parsedStructureForFile('calc-invalid', Settings::create()->withMultibyteSupport(true));
-        $sExpected = 'div {}
-div {}
+        $sExpected = 'div {height: calc (25% - 1em);}
+div {height: calc (25% - 1em);}
 div {}
 div {height: -moz-calc;}
 div {height: calc;}';
@@ -1240,6 +1254,19 @@ public function lonelyImport()
         self::assertSame($sExpected, $oDoc->render());
     }
 
+    /**
+     * @test
+     */
+    public function functionArithmeticInFile()
+    {
+        $oDoc = self::parsedStructureForFile('function-arithmetic', Settings::create()->withMultibyteSupport(true));
+        $sExpected = 'div {height: max(300,vh + 10);}
+div {height: max(300,vh - 10);}
+div {height: max(300,vh * 10);}
+div {height: max(300,vh / 10);}';
+        self::assertSame($sExpected, $oDoc->render());
+    }
+
     public function escapedSpecialCaseTokens()
     {
         $oDoc = $this->parsedStructureForFile('escaped-tokens');

tests/fixtures/expressions.css

@@ -0,0 +1,11 @@
+div {
+    height: (vh - 10);
+}
+
+div {
+    height: (vh - 10) / 2;
+}
+
+div {
+    height: max(5, (vh - 10));
+}

tests/fixtures/function-arithmetic.css

@@ -0,0 +1,12 @@
+div {
+    height: max(300, vh + 10);
+}
+div {
+    height: max(300, vh - 10);
+}
+div {
+    height: max(300, vh * 10);
+}
+div {
+    height: max(300, vh / 10);
+}