fix #272

.vscode/launch.json

@@ -0,0 +1,26 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+                "name": "Listen for XDebug",
+    "type": "php",
+    "request": "launch",
+    "pathMappings": {
+        "${workspaceFolder}": "${workspaceFolder}"
+    },
+    "port": 9000,
+    "log": true
+        },
+        {
+            "name": "Launch currently open script",
+            "type": "php",
+            "request": "launch",
+            "program": "${file}",
+            "cwd": "${fileDirname}",
+            "port": 9000
+        }
+    ]
+}

src/EmailLexer.php

@@ -14,6 +14,7 @@ class EmailLexer extends AbstractLexer
     const S_DOT              = 46;
     const S_DQUOTE           = 34;
     const S_SQUOTE           = 39;
+    const S_BACKTICK         = 96;
     const S_OPENPARENTHESIS  = 49;
     const S_CLOSEPARENTHESIS = 261;
     const S_OPENBRACKET      = 262;
@@ -60,6 +61,7 @@ class EmailLexer extends AbstractLexer
         ','    => self::S_COMMA,
         '.'    => self::S_DOT,
         "'"    => self::S_SQUOTE,
+        "`"    => self::S_BACKTICK,
         '"'    => self::S_DQUOTE,
         '-'    => self::S_HYPHEN,
         '::'   => self::S_DOUBLECOLON,

src/Parser/DomainPart.php

@@ -336,6 +336,7 @@ class DomainPart extends Parser
         $invalidDomainTokens = array(
             EmailLexer::S_DQUOTE => true,
             EmailLexer::S_SQUOTE => true,
+            EmailLexer::S_BACKTICK => true,
             EmailLexer::S_SEMICOLON => true,
             EmailLexer::S_GREATERTHAN => true,
             EmailLexer::S_LOWERTHAN => true,

tests/EmailValidator/EmailLexerTest.php

@@ -139,6 +139,7 @@ class EmailLexerTests extends TestCase
             array(".", EmailLexer::S_DOT),
             array("\"", EmailLexer::S_DQUOTE),
             array("'", EmailLexer::S_SQUOTE),
+            array("`", EmailLexer::S_BACKTICK),
             array("-", EmailLexer::S_HYPHEN),
             array("\\", EmailLexer::S_BACKSLASH),
             array("/", EmailLexer::S_SLASH),

tests/EmailValidator/Validation/RFCValidationTest.php

@@ -169,6 +169,7 @@ class RFCValidationTest extends TestCase
             ['test@ '],
             ['test@example.com []'],
             ["test@example.com'"],
+            ["test@exam`ple.com"],
         ];
     }