printf package:turtle

printf :: MonadIO io => Format (io ()) r -> r
turtle Turtle.Format
Print a Format string to standard output (without a trailing newline) 
>>> printf ("Hello, "%s%"!\n") "world"
Hello, world!
eprintf :: MonadIO io => Format (io ()) r -> r
turtle Turtle.Format
Print a Format string to standard err (without a trailing newline) 
>>> eprintf ("Hello, "%s%"!\n") "world"
Hello, world!