Issue/58 bugfix turtle bool parser (#59)

* Bugfix parsing boolean values in Turtle: Case where boolean value is directly followed by other char without whitespace. Fixes #58

---------

Co-authored-by: Konrad Abicht <hi@inspirito.de>

lib/Parser/Turtle.php

@@ -906,6 +906,9 @@ protected function parseQNameOrBoolean()
                 $value = $prefix;
 
                 if ('true' == $value || 'false' == $value) {
+                    // Unread last character
+                    $this->unread($c);
+
                     return [
                         'type' => 'literal',
                         'value' => $value,

test/fixtures/turtle/gh58-sweetrdf-bool-parser.ttl

@@ -0,0 +1,11 @@
+@prefix : <http://example.org/#> .
+
+# Allow reserved chars directly after boolean values (no whitespace)
+# See https://github.com/sweetrdf/easyrdf/issues/58
+:foo :bar true.
+
+:foo :bar false;
+  :bar :baz ;
+.
+
+:foo :bar true,false.

tests/EasyRdf/Parser/TurtleTest.php

@@ -608,4 +608,17 @@ public function testIssue52()
     {
         $this->turtleTestCase('gh52-sweetrdf-whitespace-langtag');
     }
+
+    /**
+     * Bug in Turtle parser for boolean value that is directly followed by a semicolon
+     *
+     * @see https://github.com/sweetrdf/easyrdf/issues/58
+     */
+    public function testIssue58()
+    {
+        // Test file should parse without exceptions
+        $this->expectNotToPerformAssertions();
+
+        $this->parseTurtle('turtle/gh58-sweetrdf-bool-parser.ttl');
+    }
 }