On Thu, Mar 23, 2006 at 09:20:10AM -0800, Reilly Hayes wrote:
My question originates with the statement at the bottom of page 205 (the 5th page of the paper) regarding the behavior of the function 'first': " ... while 'first' routes the state through f:". My problem is that this statement appears to be erroneous. My reading of the code would indicate that 'first' does not do this at all. The state portion of the Arrow remains unaltered.
Try this picture: (s,(b,d)) | | unassoc v ((s,b), d) | | f | x | id v v ((s',c), d) | | assoc v (s',(c,d)) The state type is not changed, but its value can be. It is the second part of the input (d) that is passed through.