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EffectSystem

v8	v9
40	40	In this type, `!e1` is an ''effect variable'', much like `a` is a type variable. `!Console` is an ''effect constructor'' that tells us what else happens when `putStr` is called, besides returning a unit value.
41	41
42		Because this second version of `putStr` doesn't have the monad in its type, we can just use the plain version of `map` and not have to worry about `mapM`.
	42	Because this second version of `putStr` doesn't have the monad in its type, in most cases we can just use the plain version of `map` and not have to worry about `mapM`.
43	43
44	44	{{{
…	…
47	47	...
48	48	}}}
	49
	50	This isn't to say that the `Monad` type class is not useful, and Disciple supports it as well. However, when writing Haskell programs we've found that most uses of `Monad` are to manage the internal state of the program. When writing Disciple programs we use effects for most state-based functions, and reserve `Monad` for things that a definitely use a different notion of sequence, like parser combinators.
49	51
50	52	== Extended type information ==