@node Introduction
@chapter Introduction
-8sync's goal is to make asynchronous programming easy. If you've worked
-with most other asynchronous programming environments, you know that it
-generally isn't. Usually asynchronous programming involves entering
-some sort of ``callback hell''. Some nicer environments like Asyncio
-for Python provide generator-based coroutines, but even these require a
-lot of work to carefully line up.
+8sync's goal is to make asynchronous programming easy.
+If you've worked with most other asynchronous programming environments,
+ you know that it generally isn't.
+Usually asynchronous programming involves entering some sort of
+ ``callback hell''.
+Some nicer environments like Asyncio for Python provide generator-based
+ coroutines, but even these require a lot of work to carefully line up.
Coding in 8sync, on the other hand, looks almost entirely like coding
-anywhere else. This is because 8sync makes great use of a cool feature
-in Guile called ``delimited continuations'' to power natural-feeling
-coroutines. Because of this, you can invoke your asynchronous code with
-a small wrapper around it, and that code will pop off to complete
-whatever other task it needs to do, and resume your function when it's
-ready passing back the appropriate value. (No need to manually chain
-the coroutines together, and no callback hell at all!)
+ anywhere else.
+This is because 8sync makes great use of a cool feature in Guile called
+ ``delimited continuations'' to power natural-feeling coroutines.
+Because of this, you can invoke your asynchronous code with a small wrapper
+ around it, and that code will pop off to complete whatever other task it
+ needs to do, and resume your function when it's ready passing back the
+ appropriate value.
+(No need to manually chain the coroutines together, and no callback hell at
+ all!)
Now that's pretty cool!
@itemize @bullet
@item
@uref{https://docs.python.org/3.5/library/asyncio.html, asyncio}
-for Python provides a nice asynchronous programming environment, and
-makes great use of generator-style coroutines. It's a bit more
-difficult to work with than 8sync (or so thinks the author) because you
-have to ``line up'' the coroutines.
+ for Python provides a nice asynchronous programming environment, and
+ makes great use of generator-style coroutines.
+It's a bit more difficult to work with than 8sync (or so thinks the author)
+ because you have to ``line up'' the coroutines.
@item
@uref{http://dthompson.us/pages/software/sly.html, Sly}
-by David Thompson is an awesome functional reactive game programming
-library for Guile. If you want to write graphical games, Sly is almost
-certainly a better choice than 8sync. Thanks to David for being very
-patient in explaining tough concepts; experience on hacking Sly greatly
-informed 8sync's development. (Check out Sly, it rocks!)
+ by David Thompson is an awesome functional reactive game programming
+ library for Guile.
+If you want to write graphical games, Sly is almost certainly a better choice
+ than 8sync.
+Thanks to David for being very patient in explaining tough concepts;
+ experience on hacking Sly greatly informed 8sync's development.
+(Check out Sly, it rocks!)
@item
Reading @uref{https://mitpress.mit.edu/sicp/, SICP}, particularly
-@uref{https://mitpress.mit.edu/sicp/full-text/book/book-Z-H-19.html#%_chap_3,
- Chapter 3's writings on concurrent systems},
-greatly informed 8sync's design.
+ @uref{https://mitpress.mit.edu/sicp/full-text/book/book-Z-H-19.html#%_chap_3,
+ Chapter 3's writings on concurrent systems},
+ greatly informed 8sync's design.
@item
Finally, @uref{https://docs.python.org/3.5/library/asyncio.html, XUDD}
-was an earlier ``research project'' that preceeded 8sync. It attempted
-to bring an actor model system to Python. However, the author
-eventually grew frustrated with some of Python's limitations, fell in
-love with Guile, and well... now we have 8sync, which is much more
-general anyway.
+ was an earlier ``research project'' that preceeded 8sync.
+It attempted to bring an actor model system to Python.
+However, the author eventually grew frustrated with some of Python's
+ limitations, fell in love with Guile, and well... now we have 8sync, which
+ is much more general anyway.
@end itemize
The motivation to build 8sync came out of
-@uref{https://lists.gnu.org/archive/html/guile-devel/2015-10/msg00015.html, a conversation}
-at the FSF 30th party between Mark Weaver, David Thompson, Andrew
-Engelbrecht, and Christopher Allan Webber over how to build
-an asynchronous event loop for Guile and just what would be needed.
+ @uref{https://lists.gnu.org/archive/html/guile-devel/2015-10/msg00015.html,
+ a conversation}
+ at the FSF 30th party between Mark Weaver, David Thompson, Andrew
+ Engelbrecht, and Christopher Allan Webber over how to build
+ an asynchronous event loop for Guile and just what would be needed.
A little over a month after that, hacking on 8sync began!
@chapter 8sync's license and general comments on copyleft
8sync is released under the GNU LGPL (Lesser General Public License),
-version 3 or later, as published by the Free Software Foundation. The
-short version of this is that if you distribute a modifications to
-8sync, whether alone or in some larger combination, must release the
-corresponding source code. In general, it is best to contribute them
-back to 8sync under the same terms; we'd appreciate any enhancements or
-fixes to be contributed upstream to 8sync itself. (This is an
-intentional oversimplification for brevity, please read the LGPL for the
-precise terms.)
+ version 3 or later, as published by the Free Software Foundation.
+The short version of this is that if you distribute a modifications to
+ 8sync, whether alone or in some larger combination, must release the
+ corresponding source code.
+In general, it is best to contribute them back to 8sync under the same terms;
+ we'd appreciate any enhancements or fixes to be contributed upstream to
+ 8sync itself.
+(This is an intentional oversimplification for brevity, please read the LGPL
+ for the precise terms.)
This usage of the LGPL helps us ensure that 8sync and derivatives of
-8sync as a library will remain free. However, we cannot provide the
-same freedom-protecting requirements for applications built on top of
-8sync. Though it is not a requirement, we request you use 8sync to
-build free software rather than use it to contribute to the growing
-world of proprietary software.
+8sync as a library will remain free.
+However, we cannot provide the same freedom-protecting requirements for
+ applications built on top of 8sync.
+Though it is not a requirement, we request you use 8sync to build free
+ software rather than use it to contribute to the growing world of
+ proprietary software.
The choice of the LGPL for 8sync was a strategic one, though in general,
-we encourage stronger copyleft. (For more thinking on this position, see
-@uref{https://www.gnu.org/licenses/why-not-lgpl.html,
- Why you shouldn't use the Lesser GPL for your next library}.)
+ we encourage stronger copyleft.
+(For more thinking on this position, see
+ @uref{https://www.gnu.org/licenses/why-not-lgpl.html,
+ Why you shouldn't use the Lesser GPL for your next library}.)
In particular, if you are building a library or application that uses
-8sync in some useful way, consider releasing your program under the GNU
-GPL or GNU AGPL! In a world where more and more software is locked
-down, where software is used to restrict users, we could use every
-chance we can get to provide protections so that software which is free
-remains free, and encourages even more software freedom to be built upon
-it.
+ 8sync in some useful way, consider releasing your program under the GNU
+ GPL or GNU AGPL!
+In a world where more and more software is locked down, where software is used
+ to restrict users, we could use every chance we can get to provide
+ protections so that software which is free remains free, and encourages even
+ more software freedom to be built upon it.
So to answer the question, ``Can I build a proprietary program on top of
-8sync?'' our response is ``Yes, but please don't. Choose to release
-your software under a freedom-respecting license. And help us turn the
-tide towards greater software freedom... consider a strong copyleft
-license!''
+ 8sync?'' our response is
+ ``Yes, but please don't.
+ Choose to release your software under a freedom-respecting license.
+ And help us turn the tide towards greater software freedom...
+ consider a strong copyleft license!''
@node Copying This Manual