QuotedField.swift

    func testQuotedField() throws {
        let quotedField = Parse {
            "|".utf8
            Many(into: "") { result, element in
                result += String(element)!
            } element: {
                OneOf {
                    Parse { "||".utf8 }.map { Substring("|").utf8 }
                    Prefix(1...) { $0 != .init(ascii: "|") }
                }
            }
            "|".utf8
        }

        let input = "|Clarice loves ||Bob|||"
        let result = try quotedField.parse(input)
        XCTAssertEqual("Clarice loves |Bob|", result)
    }