The fundamental concept here is the monad, and Greg has a novel and conceptually simplified explanation of what a monad is and why it matters. This is a very important and required first step in the series since the whole of it is about the application of monadic composition to real world web development.

In **part 4, **Greg primarily focuses on the idea that *a monad is really an API—*a view into the organization of data and control structures, not those structures themselves. In OO terms, it's an *interface*. To make this point concrete, Greg explores one of the simplest possible data structures supporting at least two different, though consistent, interpretations of the same API. The structure used, Conway's partisan games, turns out to be tailor-made for this investigation. Not only does this data structure have the requisite container-like shape, it provides opportunities to see just what's necessary in a container to implement the monadic interface.

Running throughout the presentation is a more general comparison of reuse between an OO approach and a more functional one. When the monadic API is "mixed into" the implementing structure, we get less reuse than when the implementing structure is passed as a type parameter. Finally, doing the work puts us in a unique position to see not just how to generalize Conway's construction *monadically*, but also the underlying pattern that allows the generalization to suggest itself.**Source code for the Conway game****Slides for this presenation**

The fundamental concept here is the monad, and Greg has a novel and conceptually simplified explanation of what a monad is and why it matters. This is a very important and required first step in the series since the whole of it is about the application of monadic composition to real world web development.

In **part 3**, Greg continues to take us on a monadic journey, en route to the design of a composable web stack from client to database. This series is specifically about monadic design patterns and not implementation details using Scala and asscoiated dev tools. Open your minds and let the design pattern knowledge in.

Shape. Wrap. Roll.

]]>The fundamental concept here is the monad, and Greg has a novel and conceptually simplified explanation of what a monad is and why it matters. This is a very important and required first step in the series since the whole of it is about the application of monadic composition to real world web development.

In part 2, Greg continues to take us on a monadic journey, en route to the design a composable web system from client to database and back. Tune in. Learn.

Shape. Wrap. Roll.

See **part 1 **first, if you haven't already...

See **part 3**

Greg has a very novel and conceptually simplified explanation of what a monad is and why it really matters. This is very important and a required first step in this series since this is all about the application of monadic composition to real world web development. What does this mean? Why does it matter?

Tune in.

Let's see if Greg's monadic analogies prove helpful for everyday developers in getting their heads around the elusive and beautifully complex monad.

Shape. Wrap. Roll.

See part 2

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