Note 10 - Stock-based Compensation - Summary of Stock Option Activity (Details) - $ / shares		12 Months Ended
		May 01, 2021	May 02, 2020	Apr. 27, 2019
Options outstanding, beginning of year (in shares)		389,090
Options outstanding, beginning of year (in dollars per share)	[1]	$ 7.01
Granted (in shares)		266,500	0	18,000
Granted (in dollars per share)	[1]	$ 31.27
Exercised (in shares)		(69,490)
Exercised (in dollars per share)	[1]	$ 6.99
Cancelled (in shares)		(25,000)
Cancelled (in dollars per share)	[1]	$ 5.46
Options outstanding, end of year (in shares)		561,100	389,090
Options outstanding, end of year (in dollars per share)	[1]	$ 17.74	$ 7.01
Options exercisable, end of year (in shares)		285,700
Options exercisable, end of year (in dollars per share)	[1]	$ 7.46

[1] Weighted average exercise price.