Add new stream highlighting function

src/parser/parser_types.nim

@@ -353,6 +353,40 @@ func highlightStreamPosition(stream: string, position: int): string =
 
   return a & LEFT_HIGHLIGHT_CHAR & ch & RIGHT_HIGHLIGHT_CHAR & b
 
+func highlightStreamPosition2(stream: string, position: int): string =
+  if position < 0: return stream
+  if position > stream.len - 1: return stream
+
+  let startIndex = stream.rfind("\n", 0, position)
+  let lineStartIndex =
+    case startIndex:
+      of -1: 0
+      else: startIndex
+
+  let endIndex = stream.find("\n", position)
+  let lineEndIndex =
+    case endIndex:
+      of -1: stream.len - 1
+      else: endIndex
+
+  let spaceChars = " ".repeat(position - lineStartIndex)
+  let lineChars = "_".repeat((lineEndIndex - position) + 10)
+
+  let ch = stream[position]
+  let escapedChar =
+    case ch:
+      of '\n': "\\n"
+      of ' ': "\\s"
+      else: $ch
+
+  let insertMessageAtIndex =
+    case ch:
+      # Print indicator for newlines on the previous line, which looks better for the reader
+      of '\n': (lineEndIndex - 1).max(0)
+      else: lineEndIndex
+
+  stream.dup(insert(&"\n{spaceChars}^{lineChars} Char at \"{escapedChar}\"\n", insertMessageAtIndex))
+
 proc `$`*(x: ParserState): string =
   &"""ParserState(
   stream: "{x.stream.highlightStreamPosition(x.position)}",