Yes – it’s known as printf() debugging, named after the ubiquitous C function: Used to describe debugging work done by inserting commands that output more or less carefully chosen status information at key points in the program flow, observing that information and deducing what’s wrong based on that information. — printf() debugging@everything2 Native users of … Read more
p() is a Kernel method It writes obj.inspect to the standard output. Because Object mixes in the Kernel module, the p() method is available everywhere. It’s common, btw, to use it in poetry mode, meaning that the parens are dropped. The CSV snippet can be written like… CSV.open ‘data.csv’, ‘r’ do |row| p row end … Read more
trace is the easiest to use method for debugging. It’s not in IO exactly for the reason you pointed: no need to lift your code in the IO monad. It’s implemented like this trace :: String -> a -> a trace string expr = unsafePerformIO $ do putTraceMsg string return expr So there is IO … Read more
Possibly: puts variable.inspect