Add test for chars

src_v2/parser/parser_internals.nim

@@ -248,6 +248,17 @@ when isMainModule:
 
   block testBlockChar:
     let ch1 = ch('1')
+    let ch2 = ch('2')
+    let ch3 = ch('3')
     let chDigits = ch(Digits)
+
     assert testParser123.flatMap(ch1).tokensToString() == "1"
     assert testParser123.flatMap(chDigits).tokensToString() == "1"
+
+    # Mismatch
+    assert testParser123.flatMap(ch('2')).error().kind == charMismatchErr
+    assert testParser123.flatMap(ch(Letters)).error().kind == charMismatchErr
+
+    # Out of bounds
+    assert initParserResult("").flatMap(ch1).error().kind == endOfStringErr
+    assert initParserResult("1").flatMap(ch1).flatMap(ch1).error().kind == endOfStringErr

src_v2/parser/parser_types.nim

@@ -92,6 +92,7 @@ func tokenStringValue*(x: ParserToken): string =
 func tokensToString*(tokens: seq[ParserToken]): string =
   tokens.foldl(a & b.tokenStringValue(), "")
 
+
 # -- Modifiers
 
 func flattenParserTokens*(parser: Parser): ParserResult =
@@ -124,6 +125,12 @@ func foldTokens*[T](
     let err = parserResult.error()
     onError(err)
 
+func tokensToString*(parserResult: ParserResult, fallback = ""): string =
+  parserResult.foldTokens(
+    err => fallback,
+    xs => xs.tokensToString(),
+  )
+
 func setErrorExpectedField*(err: ParserError, expected: string): ParserError =
   ParserError(
     kind: err.kind,