pub const EmitCodepointLiterals = enum {
    /// Never emit Unicode code point literals.
    never,
    /// Emit Unicode code point literals for any `u8` in the printable ASCII range.
    printable_ascii,
    /// Emit Unicode code point literals for any unsigned integer with 21 bits or fewer
    /// whose value is a valid non-surrogate code point.
    always,

    /// If the value should be emitted as a Unicode codepoint, return it as a u21.
    fn emitAsCodepoint(self: @This(), val: anytype) ?u21 {
        // Rule out incompatible integer types
        switch (@typeInfo(@TypeOf(val))) {
            .int => |int_info| if (int_info.signedness == .signed or int_info.bits > 21) {
                return null;
            },
            .comptime_int => {},
            else => comptime unreachable,
        }

        // Return null if the value shouldn't be printed as a Unicode codepoint, or the value casted
        // to a u21 if it should.
        switch (self) {
            .always => {
                const c = std.math.cast(u21, val) orelse return null;
                if (!std.unicode.utf8ValidCodepoint(c)) return null;
                return c;
            },
            .printable_ascii => {
                const c = std.math.cast(u8, val) orelse return null;
                if (!std.ascii.isPrint(c)) return null;
                return c;
            },
            .never => {
                return null;
            },
        }
    }
}