improve ast check on pipe expressions

compiler/src/prog8/compiler/astprocessing/AstChecker.kt

@@ -1103,9 +1103,15 @@ internal class AstChecker(private val program: Program,
         }
     }
 
-    override fun visit(pipe: PipeExpression) = process(pipe)
+    override fun visit(pipe: PipeExpression) {
+        process(pipe)
+        super.visit(pipe)
+    }
 
-    override fun visit(pipe: Pipe) = process(pipe)
+    override fun visit(pipe: Pipe) {
+        process(pipe)
+        super.visit(pipe)
+    }
 
     private fun process(pipe: IPipe) {
         if(pipe.source in pipe.segments)

docs/source/todo.rst

@@ -3,7 +3,6 @@ TODO
 
 For next release
 ^^^^^^^^^^^^^^^^
-- "999 as ubyte" won't be const folded away and gives compiler crash
 - pipe operator: allow non-unary function calls in the pipe that specify the other argument(s) in the calls.
 - createAssemblyAndAssemble(): make it possible to actually get rid of the VarDecl nodes by fixing the rest of the code mentioned there.
 - allow "xxx" * constexpr  (where constexpr is not a number literal), now gives expression error not same type

examples/test.p8

@@ -6,7 +6,6 @@
 
 main {
     sub start() {
-
         uword qq = 999 as ubyte |> abs() |> abs()
         txt.print_uw(qq)
         txt.nl()