in '0'..'9' -> this - '0'
    in 'a'..'f' -> this - 'a' + 10
    in 'A'..'F' -> this - 'A' + 10
    else -> -1
  }

internal infix fun Byte.and(mask: Int): Int = toInt() and mask

internal infix fun Short.and(mask: Int): Int = toInt() and mask

internal infix fun Int.and(mask: Long): Long = toLong() and mask

@Throws(IOException::class)
internal fun BufferedSink.writeMedium(medium: Int) {

                    )
                ]
            )""".trimIndent()
        results.assert(expected)
    }

    @Test
    fun `parses infix call chain`() {
        val results = parse(
            """
            f(1) g "string" h true i 2L j 3.apply(4)
            """.trimIndent()
        )

        val expected = """

		"FAIL:\xff\x03",
		"FAIL:\xff\xd5",
		"FAIL:\xff\xff\xd5",
	}

	for _, tc := range testCases {
		want := tc[:5] == "PASS:"
		infix := tc[5:]

		data := []byte(nil)
		data = append(data, prefix...)
		data = append(data, infix...)
		data = append(data, suffix...)
		_, err := Decode(bytes.NewReader(data))
		got := err == nil

		if got != want {

		// prefix and binary operators.
		{jsCtxRegexp, "="},
		{jsCtxRegexp, "+="},
		{jsCtxRegexp, "*="},
		{jsCtxRegexp, "*"},
		{jsCtxRegexp, "!"},
		// Whether the + or - is infix or prefix, it cannot precede a
		// div op.
		{jsCtxRegexp, "+"},
		{jsCtxRegexp, "-"},
		// An incr/decr op precedes a div operator.
		// This is not airtight. In (g = ++/h/i) a regexp follows a

        val firCall = infixCallExpression.getOrBuildFirSafe<FirFunctionCall>(firResolveSession) ?: return null

        // There is only one parameter for infix functions; get its type
        val argumentsToParameters = firCall.argumentsToSubstitutedValueParameters(substituteWithErrorTypes = false) ?: return null

	}

	// All cases below are in the single-byte UTF-8 group.
	switch c, n := s[len(s)-1], len(s); c {
	case '+', '-':
		// ++ and -- are not regexp preceders, but + and - are whether
		// they are used as infix or prefix operators.
		start := n - 1
		// Count the number of adjacent dashes or pluses.
		for start > 0 && s[start-1] == c {
			start--
		}
		if (n-start)&1 == 1 {