Added BuilderFactory->concat() method

lib/PhpParser/BuilderFactory.php

@@ -3,6 +3,9 @@
 namespace PhpParser;
 
 use PhpParser\Builder;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\BinaryOp\Concat;
+use PhpParser\Node\Scalar\String_;
 use PhpParser\Node\Stmt\Use_;
 
 /**
@@ -120,14 +123,34 @@ class BuilderFactory
     /**
      * Creates node a for a literal value.
      *
-     * @param Node\Expr|bool|null|int|float|string|array $value $value
+     * @param Expr|bool|null|int|float|string|array $value $value
      *
-     * @return Node\Expr
+     * @return Expr
      */
     public function val($value) {
         return BuilderHelpers::normalizeValue($value);
     }
 
+    /**
+     * Creates nested Concat nodes from a list of expressions.
+     *
+     * @param Expr|string ...$exprs Expressions or literal strings
+     *
+     * @return Concat
+     */
+    public function concat(...$exprs) {
+        $numExprs = count($exprs);
+        if ($numExprs < 2) {
+            throw new \LogicException('Expected at least two expressions');
+        }
+
+        $lastConcat = $this->normalizeStringExpr($exprs[0]);
+        for ($i = 1; $i < $numExprs; $i++) {
+            $lastConcat = new Concat($lastConcat, $this->normalizeStringExpr($exprs[$i]));
+        }
+        return $lastConcat;
+    }
+
     public function __call($name, array $args) {
         if (method_exists($this, '_' . $name)) {
             return $this->{'_' . $name}(...$args);
@@ -135,4 +158,16 @@ class BuilderFactory
 
         throw new \LogicException(sprintf('Method "%s" does not exist', $name));
     }
+
+    private function normalizeStringExpr($expr) {
+        if ($expr instanceof Expr) {
+            return $expr;
+        }
+
+        if (is_string($expr)) {
+            return new String_($expr);
+        }
+
+        throw new \LogicException('Expected string or Expr');
+    }
 }

test/PhpParser/BuilderFactoryTest.php

@@ -3,6 +3,7 @@
 namespace PhpParser;
 
 use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\BinaryOp\Concat;
 use PhpParser\Node\Scalar\String_;
 
 class BuilderFactoryTest extends \PHPUnit_Framework_TestCase
@@ -45,6 +46,42 @@ class BuilderFactoryTest extends \PHPUnit_Framework_TestCase
         );
     }
 
+    public function testConcat() {
+        $factory = new BuilderFactory();
+        $varA = new Expr\Variable('a');
+        $varB = new Expr\Variable('b');
+        $varC = new Expr\Variable('c');
+
+        $this->assertEquals(
+            new Concat($varA, $varB),
+            $factory->concat($varA, $varB)
+        );
+        $this->assertEquals(
+            new Concat(new Concat($varA, $varB), $varC),
+            $factory->concat($varA, $varB, $varC)
+        );
+        $this->assertEquals(
+            new Concat(new Concat(new String_("a"), $varB), new String_("c")),
+            $factory->concat("a", $varB, "c")
+        );
+    }
+
+    /**
+     * @expectedException \LogicException
+     * @expectedExceptionMessage Expected at least two expressions
+     */
+    public function testConcatOneError() {
+        (new BuilderFactory())->concat("a");
+    }
+
+    /**
+     * @expectedException \LogicException
+     * @expectedExceptionMessage Expected string or Expr
+     */
+    public function testConcatInvalidExpr() {
+        (new BuilderFactory())->concat("a", 42);
+    }
+
     public function testIntegration() {
         $factory = new BuilderFactory;
         $node = $factory->namespace('Name\Space')