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gregoryyoung/gist:a3e69ed58ae066b91f1b

Created June 24, 2015 13:25
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Event Sourcing as 3 functions.
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gistfile1.txt
f(events) -> state
match f(state, event) -> state
f(state, command) -> events
@fride
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fride commented Jun 25, 2015

I'm not sure about the semantics of ' match f(state, event) -> state'. Care to explain?

@jbrains
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jbrains commented Jun 25, 2015

I'm guessing it's "figure out which ones of events apply to state, then apply it."

@fride
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fride commented Jun 30, 2015

Sounds sensible.

@kijanawoodard
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Given a state and a event, produce a new state

match is how you progress through the collection of events - f(events)

@gregoryyoung
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@kijanawoodard yes.

in some systems it may even be more complex than just match by type (see erlang/haskell)

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