From 51b34e6a27619804c742bcb62e775e2ef9e45276 Mon Sep 17 00:00:00 2001
From: Florian Schroedl <flo.schroedl@gmail.com>
Date: Sun, 28 Aug 2022 13:48:41 +0200
Subject: [PATCH] Restore tryTokenize function

---
 src_v2/parser/builder_api.nim | 113 ++++++++++++++++++++++++++++++++++
 src_v2/parser/parser.nim      |   2 +
 2 files changed, 115 insertions(+)
 create mode 100644 src_v2/parser/builder_api.nim

diff --git a/src_v2/parser/builder_api.nim b/src_v2/parser/builder_api.nim
new file mode 100644
index 0000000..e213063
--- /dev/null
+++ b/src_v2/parser/builder_api.nim
@@ -0,0 +1,113 @@
+import std/[
+  collections/sequtils,
+  options,
+  strformat,
+  strutils,
+  sugar,
+]
+import fp/[
+  resultM
+]
+import ./builder_types
+import ./parser_types
+import ./parser_api
+
+# -- Builder API
+
+proc tryTokenize*[T](
+  builder: Builder[T],
+  builderFns: seq[tuple[
+    parserFn: parserFnT,
+    tokenizerFn: seq[ParserToken] -> seq[T],
+  ]],
+  defaultTokenizerFn: seq[ParserToken] -> seq[T],
+  stopAtParserFn = newlineOrEol,
+  concatTokensFn = concat[T],
+): BuilderResult[T] =
+  ## Try to tokenize text in `builder` by checking `builderFns` seq for a sucessful `parserFn`.
+  ## When a `parserFn.ok` is found, tokenize the text in the `Parser` using the current tokenizerFn
+  ## and merge the result into `builder.tree` using the `concatTokensFn`.
+  ## When no parser matches, tokenize with the `defaultTokenizerFn` until `stopAtParserFn is matched.
+
+  let (parser, tree) = builder
+  # Mutating accumulators
+  var parserAcc: ParserResult = ParserResult.ok(parser)
+  var builderAcc: Builder[T] = builder
+
+  while parserAcc.isOk() and parserAcc.flatMap(stopAtParserFn).isErr():
+    # Empty the parser tokens as we want to seperate them for the next parser in the sequence
+    let emptyParser = parserAcc.map(emptyTokens)
+
+    # Find the a parser and convert its tokens with the `tokenizerFn`
+    var found = false
+    for fn in builderFns:
+      let (parserFn, tokenizerFn) = fn
+
+      let parseResult = emptyParser.flatMap(parserFn)
+      if parseResult.isOk():
+        found = true
+
+        # Convert all previous unmatched tokens via the `defaultTokenizerFn`
+        let defaultBuilderTokens = parserAcc
+        .foldTokens(
+          onErrorFn = _ => newSeq[T](),
+          onSuccessFn = defaultTokenizerFn,
+        )
+
+        let okParser = parseResult.unsafeGet()
+        parserAcc = parseResult.map(emptyTokens)
+        builderAcc = initBuilder(
+          okParser,
+          concatTokensFn(
+            builderAcc.tree,
+            defaultBuilderTokens,
+            tokenizerFn(okParser.tokens),
+          )
+        )
+        break
+
+    if not found:
+      parserAcc = parserAcc.flatMap(anyCh)
+
+  let defaultBuilderTokens = parserAcc
+  .foldTokens(
+    onErrorFn = _ => newSeq[T](),
+    onSuccessFn = defaultTokenizerFn,
+  )
+
+  BuilderResult[T].ok(initBuilder(
+    builderAcc.parser,
+    concatTokensFn(
+      builderAcc.tree,
+      defaultBuilderTokens,
+    ),
+  ))
+
+when isMainModule:
+  type TestStringBuilderT* = string
+  type TestStringBuilder* = Builder[TestStringBuilderT]
+  type TestStringBuilderResult* = BuilderResult[TestStringBuilderT]
+
+  block testApi:
+    let testParensParser = anyBetween(str(" ("), str(") "))
+
+    func testDefaultTokenizer(tokens: seq[ParserToken]): seq[string] {.closure.} =
+      @[tokens.toString()]
+    func testParensTokenizer(tokens: seq[ParserToken]): seq[string] {.closure.} =
+      @[&"Parens({tokens.toString()})"]
+
+    let testBuilder = initBuilder(
+      initParser("""sentence (with parens) and more
+And ignore this part"""),
+      newSeq[TestStringBuilderT]()
+    )
+    .tryTokenize(
+      builderFns = @[(
+        testParensParser,
+        testParensTokenizer
+      )],
+      defaultTokenizerFn = testDefaultTokenizer,
+    )
+
+    assert testBuilder.isOk() == true
+    assert testBuilder.unsafeGet().tree == @["sentence", "Parens(with parens)", "and more"]
diff --git a/src_v2/parser/parser.nim b/src_v2/parser/parser.nim
index 5fb2662..6e22075 100644
--- a/src_v2/parser/parser.nim
+++ b/src_v2/parser/parser.nim
@@ -1,7 +1,9 @@
 import parser_types
 import parser_api
 import builder_types
+import builder_api
 
 export parser_types
 export parser_api
 export builder_types
+export builder_api