How to use the parser-ts.char.many function in parser-ts

import { pipe } from 'fp-ts/lib/pipeable'
import { run } from 'parser-ts/lib/code-frame'

const isDigit = (c: string): boolean => '0123456789'.indexOf(c) !== -1

const isPunctuation = (c: string): boolean => '| =\n():,{};[]->'.indexOf(c) !== -1

const identifierFirstLetter = P.sat(c => !isDigit(c) && !isPunctuation(c))

const identifierBody = P.sat(c => !isPunctuation(c))

/**
 * @since 0.4.0
 */
export const identifier: P.Parser = P.expected(
  S.fold([identifierFirstLetter, C.many(identifierBody)]),
  'an identifier'
)

const leftParens: P.Parser = S.fold([C.char('('), S.spaces])

const rightParens: P.Parser = S.fold([S.spaces, C.char(')')])

const withParens = <a>(parser: P.Parser): P.Parser =&gt; {
  return pipe(
    leftParens,
    P.apSecond(parser),
    P.apFirst(rightParens)
  )
}

const unparametrizedRef: P.Parser = pipe(</a>