
The Art of the Propagator (2009) [pdf] - kylerpalmer
https://dspace.mit.edu/bitstream/handle/1721.1/44215/MIT-CSAIL-TR-2009-002.pdf
======
philzook
This is also intimately connected with Ed Kmett's Guanxi project

[https://www.youtube.com/watch?v=D7rlJWc3474](https://www.youtube.com/watch?v=D7rlJWc3474)
[https://github.com/ekmett/guanxi](https://github.com/ekmett/guanxi)

My understanding is he is using ideas from propagators and other places to
make a performant logic programming framework in Haskell.

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joshmarlow
The section in SICP on circuit simulation has some similar ideas. I like to
think that that was an early version of the propagator idea -
[https://mitpress.mit.edu/sites/default/files/sicp/full-
text/...](https://mitpress.mit.edu/sites/default/files/sicp/full-
text/book/book-Z-H-22.html#%_sec_3.3.4)

~~~
kkylin
The constraint language described in SICP (AFAIK began as a paper by Gerry
Sussman and Richard Stallman, continued in the PhD thesis of Guy Steele) is
indeed an inspiration / precursor to Alexey's dissertation on propagators.

~~~
kylerpalmer
Yes, and with Alexey's work (if I've understood it) the propagators are
allowed to hold multiple values(beliefs) based on more than one (possibly
conflicting) set of constraints.

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tempguy9999
I won't be able to read the paper, but from the abstract it sounds a bit like
a blackboard[0]

"a common knowledge base, the "blackboard", is iteratively updated by a
diverse group of specialist knowledge sources, starting with a problem
specification and ending with a solution. Each knowledge source updates the
blackboard with a partial solution when its internal constraints match the
blackboard state. In this way, the specialists work together to solve the
problem"

I can't see the term Blackboard used in the paper. Probably irrelevant but
just an observation.

[0]
[https://en.wikipedia.org/wiki/Blackboard_system](https://en.wikipedia.org/wiki/Blackboard_system)

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amirouche
There is also miniadapton
[https://github.com/fisherdj/miniAdapton](https://github.com/fisherdj/miniAdapton)

Unlike what is explained OP, the computation is one way.

~~~
kylerpalmer
Cool. Found the paper:
[https://arxiv.org/pdf/1609.05337.pdf](https://arxiv.org/pdf/1609.05337.pdf)

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voidhorse
Nice! I’ve been spending a lot of time with Radul’s thesis, which is also on
propagator networks, trying to follow along and implement a reactive framework
using its teachings. Fun times

~~~
kylerpalmer
Nice! I just found out about it today. Is your project open-source?

Edit: found Radul's thesis:
[https://dspace.mit.edu/bitstream/handle/1721.1/54635/6035432...](https://dspace.mit.edu/bitstream/handle/1721.1/54635/603543210-MIT.pdf)

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agumonkey
is Sussman still fond of this ? he was talking about it in meetups IIRC

~~~
kylerpalmer
I've only just heard of it from a talk he gave a few years back [1]. Not sure
whether he's continued working with it.

[1]:
[https://www.youtube.com/watch?v=O3tVctB_VSU](https://www.youtube.com/watch?v=O3tVctB_VSU)

