Add implementation test

src_v2/parser/parser_internals.nim

@@ -324,7 +324,7 @@ when isMainModule:
     # parse
     assert testAbc1Parser.flatMap(following(@[ch('a'), str("bc"), digit])).tokensToString() == "abc1"
 
-  block parsingHelpers:
+  block testParsingHelpers:
     let testParenParser = initParserResult("(123)")
     let testQuoteParser = initParserResult("\"123\"")
 
@@ -338,8 +338,18 @@ when isMainModule:
     assert testParenParser.flatMap(anyBetween(ch('('), ch(')'))).tokensToString() == "123"
     assert testQuoteParser.flatMap(anyBetweenPair(testQuote)).tokensToString() == "123"
 
-  block parsingAliases:
+  block testParsingAliases:
     assert initParserResult("").flatMap(newlineOrEol).isOk() == true
     assert initParserResult("abc ").flatMap(str("abc") + newlineOrEol).error().expected == newlineEolExpectedErr
     assert initParserResult("").flatMap(whitespaceOrEol).isOk() == true
     assert initParserResult("abc ").flatMap(str("abc") + whitespaceOrEol + whitespaceOrEol).tokensToString() == "abc "
+
+  block testImplementations:
+    let testSentenceStr = "This is a sentence\n\nFollowing another sentence."
+    let testSentenceParser = initParserResult(testSentenceStr)
+
+    let testSentence1 = anyUntil(newline) + newline + newlineOrEol +
+    manyUntil(choice(@[letter, whitespace]), ch('.')) + ch('.') +
+    newlineOrEol
+
+    assert testSentenceParser.flatMap(testSentence1).tokensToString() == testSentenceStr