From 197862569ed7f39053c8c8273a8af4a779fb4f93 Mon Sep 17 00:00:00 2001
From: Florian Schroedl <flo.schroedl@gmail.com>
Date: Fri, 26 Aug 2022 22:02:44 +0200
Subject: [PATCH] Basic builder structure

---
 src_v2/parser/builder_types.nim | 74 ++++++++++++++++++++++++++++++++-
 1 file changed, 73 insertions(+), 1 deletion(-)

diff --git a/src_v2/parser/builder_types.nim b/src_v2/parser/builder_types.nim
index 208e72b..eca8d1d 100644
--- a/src_v2/parser/builder_types.nim
+++ b/src_v2/parser/builder_types.nim
@@ -1,7 +1,11 @@
+import std/[
+  sugar,
+]
 import fp/[
   resultM,
 ]
 import ./parser_types
+import ./parser_api
 
 type
   Builder*[T] = tuple[
@@ -12,5 +16,73 @@ type
     parserError
   BuilderError*[T] = ref object
     kind*: builderErrorKind
-    builder*: Builder[T]
+    parser*: ParserError
+    tree*: seq[T]
   BuilderResult*[T] = Result[Builder[T], BuilderError[T]]
+
+# -- Initalizers
+
+proc initBuilder*[T](parser: Parser, tree: seq[T]): Builder[T] =
+  Builder[T]((
+    parser,
+    tree
+  ))
+
+# -- Modifiers
+
+proc setParser*[T](builder: Builder[T], parser: Parser): Builder[T] =
+  Builder[T]((
+    parser,
+    builder.tree,
+  ))
+
+proc setTree*[T](builder: Builder[T], tree: seq[T]): Builder[T] =
+  Builder[T]((
+    builder.parser,
+    tree,
+  ))
+
+proc tryParser*[T](
+  builder: Builder[T],
+  parserFn: parserFnT,
+): BuilderResult[T] =
+  ## Try out a `parser` on a `builder`
+  ## When successful return the original builder, otherwise return an error
+  let parser = ParserResult
+  .ok(Parser(
+    state: builder.parser.state,
+    tokens: @[],
+  ))
+  .flatMap(parserFn)
+
+  parser
+  .foldTokens(
+    (err: ParserError) => BuilderResult[T].err(BuilderError[T](
+      kind: parserError,
+      parser: err,
+      tree: builder.tree,
+    )),
+    (newTokens: seq[ParserToken]) => BuilderResult[T].ok(builder),
+  )
+
+when isMainModule:
+  type TestStringBuilderT* = string
+  type TestStringBuilder* = Builder[TestStringBuilderT]
+  type TestStringBuilderResult* = BuilderResult[TestStringBuilderT]
+
+  let testBuilder123 = initBuilder(
+    initParser("123"),
+    newSeq[TestStringBuilderT]()
+  )
+
+  block testModifiers:
+    # setters
+    assert testBuilder123.setParser(initParser("abc")).parser.state.stream == "abc"
+    assert testBuilder123.setTree(@["abc"]).tree[0] == "abc"
+
+    # tryParser
+    assert testBuilder123.tryParser(ch('1')).isOk() == true
+    assert testBuilder123.tryParser(ch('2')).isErr() == true
+
+  # echo testBuilder123
+  # block testModifiers: