Parsec - improving error message for "between"-CodePudding

I'm learning Parsec. I've got this code:

import Text.Parsec.String (Parser)
import Control.Applicative hiding ((<|>))
import Text.ParserCombinators.Parsec hiding (many)

inBracketsP :: Parser [String]
inBracketsP = (many $ between (char '[') (char ']') (many $ char '.')) <* eof

main :: IO ()
main =  putStr $ show $ parse inBracketsP "" "[...][..."

The result is

Left (line 1, column 10):
unexpected end of input
expecting "." or "]"

This message is not useful (adding . won't fix the problem). I'd expect something like ']' expected (only ] fixes the problem).

Is it possible to achieve that easily with Parsec? I've seen the SO question Parsec: error message at specific location, which is inspiring, but I'd prefer to stick to the between combinator, without manual lookahead or other overengineering (kind of), if possible.

CodePudding user response：

You can hide a terminal from being displayed in the expected input list by attaching an empty label to it (parser <?> ""):

inBracketsP :: Parser [String]
inBracketsP = (many $ between (char '[') (char ']') (many $ (char '.' <?> ""))) <* eof

-- >>> main
-- Left (line 1, column 10):
-- unexpected end of input
-- expecting "]"

In megaparsec, there is also a hidden combinator that achieves the same effect.