diff --git a/src/test.nim b/src/test.nim
index c7723bf..95191fd 100644
--- a/src/test.nim
+++ b/src/test.nim
@@ -3,15 +3,16 @@ import std/strutils
 import std/strformat
 import std/collections/sequtils
 import std/sugar
+import std/collections/tables
 import results
 import fusion/matching
 import fp/maybe
 import print
+import types
 
 {.experimental: "caseStmtMacros".}
 
 type
-
   ParserState* = ref object
     stream: string
     position, lastPosition: int
@@ -35,10 +36,11 @@ type
     parser: Parser
   ParserResult* = Result[Parser, ParserError]
 
-  # Builder[T]* = ref object
-  #   parser: ParserResult,
-  #   tree: seq[T],
-  # BuilderResult* = Result[Builder, (Builder, string)]
+  Builder*[T] = tuple[
+    parser: ParserResult,
+    tree: seq[T]
+  ]
+  BuilderResult*[T] = Result[Builder[T], (Builder[T], string)]
 
 # func prettyPrintError*(err: ParserErrror,)
 
@@ -260,6 +262,21 @@ proc foldTokens[T](
     let err = parserResult.error()
     onError(err)
 
+
+# proc mapTree[T](builder: BuilderResult[T], fn: Builder[T] -> Builder[T]) =
+#   builder.map(proc(b: Builder) =
+#                 (@parser, @builder) := builder
+#                 b
+#   )
+
+# proc applyParserTokens[T](builder: BuilderResult, fn: seq[Token] -> T): BuilderResult =
+#   (@parser, @builder) := builder
+#   parser.foldTokens(
+#     proc(x: ParserError): BuilderResult = err(x),
+#     proc(xs: seq[Token]): BuilderResult = ok(parser, builder.map()),
+#   )
+
+
 when isMainModule:
   # let fooParser = initParser("FOO___BAR")
   # .parseSeq(@[
@@ -275,10 +292,44 @@ when isMainModule:
   #   xs => xs.foldl(a & b.value, "")
   # )
 
-  echo initParser("BB").parseSeq(@[
-    choice(@[ch(Digits), ch('B')]),
-  ])
+  # echo initParser("BB").parseSeq(@[
+  #   choice(@[ch(Digits), ch('B')]),
+  # ])
 
+  let parseHeadingStars = @[
+    manyUntil(ch('*'), ch(' ')),
+    ignore(ch(' '))
+  ]
+  # proc buildHeadingStars(stars: ParserResult, builder: OrgElement): OrgElement =
+  #   builder.level = stars.get().len
+
+  # let todoKeywords = @[
+  #   "TODO",
+  # ]
+  # let todoDoneKeywords = @[
+  #   "DONE",
+  # ]
+  # let parseHeadingTodo = @[
+
+  # ]
+
+  # let buildHeadingStars =
+  type StringBuilder = BuilderResult[string]
+
+  let sampleBuilder: StringBuilder = StringBuilder.ok(Builder((
+    parser: initParser(""),
+    tree: newSeq[string](),
+  )))
+
+  echo sampleBuilder
+  # .mapTree((x: string) => x)
+
+
+  # @[
+  #   (parseHeadingStars, buildHeadingStars),
+  #   (parseHeadingTodo, buildHeadingTodo),
+  #   (parseHeadingContent, buildHeadingContent),
+  # ]
 
   # .parseSeq(@[
   #   manyUntil(ch('*'), ch(' ')),