implement &

Author: jrudolph

parboiled-core/src/main/scala-3/org/parboiled2/ParserMacros.scala

@@ -347,6 +347,17 @@ class OpTreeContext(parser: Expr[Parser])(using Quotes) {
       }
   }
 
+  case class AndPredicate(op: OpTree) extends DefaultNonTerminalOpTree {
+    def ruleTraceNonTerminalKey = '{ RuleTrace.AndPredicate }
+    def renderInner(start: Expr[Int], wrapped: Boolean): Expr[Boolean] =
+      '{
+        val mark    = $parser.__saveState
+        val matched = ${ op.render(wrapped) }
+        $parser.__restoreState(mark)
+        matched
+      }
+  }
+
   private case class Action(body: Term, ts: List[TypeTree]) extends DefaultNonTerminalOpTree {
     def ruleTraceNonTerminalKey = '{ RuleTrace.Action }
 
@@ -750,6 +761,8 @@ class OpTreeContext(parser: Expr[Parser])(using Quotes) {
               ) =>
             Sequence(rec(base), Action(body, ts))
 
+          case Apply(Select(_, "&"), List(arg)) => AndPredicate(rec(arg))
+
           case Apply(
                 Select(Apply(TypeApply(Select(_, "rule2WithSeparatedBy"), _), List(base)), "separatedBy"),
                 List(sep)

parboiled-core/src/test/scala/org/parboiled2/CombinatorSpec.scala

@@ -167,15 +167,15 @@ object CombinatorSpec extends TestParserSpec {
         "a" must beMismatched
         "b" must beMatched
         "" must beMatched
-      }
+      }*/
 
       "`&` modifier" - new TestParser0 {
         def targetRule = rule(&("a"))
         "a" must beMatched
         cursor ==> 0
         "b" must beMismatched
         "" must beMismatched
-      }*/
+      }
 
       "`1.times(Rule0)` modifier" - new TestParser0 {
         def targetRule = rule(1.times("a"))