Added support for the agent model.

16 files changed, 252 insertions, 53 deletions

diff --git a/documentation/book/the_lux_programming_language/appendix_a.md b/documentation/book/the_lux_programming_language/appendix_a.md
index d0b4fe8b1..4b77e10df 100644
--- a/documentation/book/the_lux_programming_language/appendix_a.md
+++ b/documentation/book/the_lux_programming_language/appendix_a.md
@@ -16,7 +16,7 @@ If you recall [Chapter 1](chapter_1.md), there was this example code:
 
 Here, we're importing the `library/lux` module.
 
-The `(.except)` option means _locally import every definition exported by the `library/lux` module_.
+The `(.except)` option means _locally_ import every definition exported by the `library/lux` module.
 
 This allows usage of those definitions without having to give them the `library/lux.` prefix, or even the `.` shortcut prefix.
 
diff --git a/documentation/book/the_lux_programming_language/appendix_c.md b/documentation/book/the_lux_programming_language/appendix_c.md
index 5bfb731ea..0ca109331 100644
--- a/documentation/book/the_lux_programming_language/appendix_c.md
+++ b/documentation/book/the_lux_programming_language/appendix_c.md
@@ -66,7 +66,7 @@ The possibilities are endless when it comes to the refinement you can do, and wh
 ... Allows you to simultaneously bind and de-structure a value.
 (def (hash (^.let set [element_hash _]))
   (list#mix (function (_ elem acc)
-              (n.+ (# element_hash hash elem) acc))
+              (n.+ (at element_hash hash elem) acc))
             0
             (set.list set)))
 ```
diff --git a/documentation/bookmark/business/productivity.md b/documentation/bookmark/business/productivity.md
index 98d8ac064..76c8acb01 100644
--- a/documentation/bookmark/business/productivity.md
+++ b/documentation/bookmark/business/productivity.md
@@ -1,6 +1,7 @@
 # Reference
 
 0. []()
+0. [Let it slide](https://world.hey.com/dhh/let-it-slide-9e40f11a)
 0. [Tips for effective engineering](https://budelewski.com/effective-engineering/)
 0. [1. Unfolding the interrelationship diagram](https://world.hey.com/rjs/1-unfolding-the-interrelationship-diagram-5a79e3fc)
 0. [2. Shaping on the demand side](https://world.hey.com/rjs/2-shaping-on-the-demand-side-f2e6a00d)
diff --git a/documentation/bookmark/compilation/target/wasm.md b/documentation/bookmark/compilation/target/wasm__WebAssembly.md
index e90bcd654..dd496d03e 100644
--- a/documentation/bookmark/compilation/target/wasm.md
+++ b/documentation/bookmark/compilation/target/wasm__WebAssembly.md
@@ -27,6 +27,7 @@
 # Reference
 
 0. []()
+0. [just-in-time code generation within webassembly](https://wingolog.org/archives/2022/08/18/just-in-time-code-generation-within-webassembly)
 0. [TeaVM: Build Fast, Modern Web Apps in Java](https://teavm.org/)
 0. [Recommendations when publishing a Wasm library](https://nickb.dev/blog/recommendations-when-publishing-a-wasm-library)
 0. [Building host implementations for WebAssembly interfaces](https://radu-matei.com/blog/wasm-components-host-implementations/)
diff --git a/documentation/bookmark/css.md b/documentation/bookmark/css.md
index c1231143a..cf49d95ba 100644
--- a/documentation/bookmark/css.md
+++ b/documentation/bookmark/css.md
@@ -6,6 +6,7 @@
 # Reference
 
 0. []()
+0. [Meet the top layer: a solution to z-index:10000](https://developer.chrome.com/blog/what-is-the-top-layer/)
 0. [Not All Zeros are Equal: And every ‘best practice’ comes with caveats](https://www.oddbird.net/2022/08/04/zero-units/)
 0. [Style scoping versus shadow DOM: which is fastest?](https://nolanlawson.com/2022/06/22/style-scoping-versus-shadow-dom-which-is-fastest/)
 0. [Got Spaghetti Stylesheets? 4 Techniques for Managing CSS Complexity](https://blog.shimin.io/4-techniques-for-managing-css-complexity/)
diff --git a/documentation/bookmark/end_user_programming.md b/documentation/bookmark/end_user_programming.md
new file mode 100644
index 000000000..ef39bbed3
--- /dev/null
+++ b/documentation/bookmark/end_user_programming.md
@@ -0,0 +1,5 @@
+# Reference
+
+0. []()
+0. [End-user Programming](https://www.inkandswitch.com/end-user-programming/)
+
diff --git a/documentation/bookmark/open_source.md b/documentation/bookmark/open_source.md
index db237a9f8..2a8c67a86 100644
--- a/documentation/bookmark/open_source.md
+++ b/documentation/bookmark/open_source.md
@@ -1,6 +1,7 @@
 # Reference
 
 0. []()
+0. [The Myth of Mass Collaboration](https://staltz.com/the-myth-of-mass-collaboration.html)
 0. [Open Source Explained](https://blog.erlend.sh/open-source-explained)
 0. [Trust Signals in Open Source Projects](https://hackernoon.com/the-signs-of-a-great-open-source-project)
 0. [Awesome OSS Monetization](https://paydevs.github.io/awesome-oss-monetization/)
diff --git a/documentation/bookmark/parallelism.md b/documentation/bookmark/parallelism.md
index d2a927171..e7fc2dae2 100644
--- a/documentation/bookmark/parallelism.md
+++ b/documentation/bookmark/parallelism.md
@@ -1,6 +1,7 @@
 # Reference
 
 0. []()
+0. [Regent: Regent is a language for implicit task-based parallelism.](https://regent-lang.org/)
 0. [The Taichi Programming Language](https://www.taichi-lang.org/)
 0. [C++ Standard Parallelism - Bryce Adelstein Lelbach - CppCon 2021](https://www.youtube.com/watch?v=LW_T2RGXego)
 0. [Arachne: Towards Core-Aware Scheduling](https://github.com/PlatformLab/Arachne)
diff --git a/documentation/bookmark/propagator.md b/documentation/bookmark/propagator.md
new file mode 100644
index 000000000..ab0cd9dd1
--- /dev/null
+++ b/documentation/bookmark/propagator.md
@@ -0,0 +1,6 @@
+# Reference
+
+0. []()
+0. [Propagators, Brainy, and Spritely - MetaFox Talks](https://www.youtube.com/watch?v=jI8gA68OXLM)
+0. [Revised Report on the Propagator Model](https://groups.csail.mit.edu/mac/users/gjs/propagators/)
+
diff --git a/documentation/bookmark/transducer_stream_pipe.md b/documentation/bookmark/transducer_stream_pipe.md
index cb8aae481..3b3cd84a8 100644
--- a/documentation/bookmark/transducer_stream_pipe.md
+++ b/documentation/bookmark/transducer_stream_pipe.md
@@ -1,5 +1,7 @@
 # Reference
 
+0. []()
+0. [Understanding transducers](https://andreyorst.gitlab.io/posts/2022-08-13-understanding-transducers/)
 0. [Complete Guide to Transducers](https://nwcalvank.dev/transducers/)
 0. [zug](https://sinusoid.es/zug/)
 0. https://dev.to/greencoder/build-your-own-transducer-and-impress-your-cat---part-1-mhp
diff --git a/documentation/bookmark/web_browser.md b/documentation/bookmark/web_browser.md
index 7c12f5de2..80ee46027 100644
--- a/documentation/bookmark/web_browser.md
+++ b/documentation/bookmark/web_browser.md
@@ -1,56 +1,61 @@
 # Exemplar
 
-1. [Nyxt](https://nyxt.atlas.engineer/)
-1. [Stack](https://stackbrowser.com/)
-1. [Flow: The super fast, multithreaded HTML5 browser from Ekioh](https://www.ekioh.com/flow-browser/)
-1. https://refresh.study/
-1. https://github.com/breach/breach_core
-1. https://github.com/browserhtml/browserhtml
-1. https://depolium.com/
-1. https://vivaldi.com/
-1. https://www.nidium.com/
-1. https://github.com/trevorlinton/webkit.js
-1. https://www.epicbrowser.com/
-1. https://minbrowser.github.io/min/
-1. https://www.palemoon.org/
-1. https://github.com/beakerbrowser/webdb
-1. https://github.com/beakerbrowser
-1. https://github.com/nEXT-Browser/nEXT
-1. https://techcrunch.com/2018/02/23/veil-is-private-browsing-for-the-ultra-paranoid/
-1. https://github.com/wexond/wexond
-1. http://next.atlas.engineer
-1. https://workona.com/
-1. https://luakit.github.io/
-1. https://www.thurrott.com/cloud/web-browsers/204669/opera-web-browser-is-reborn
+0. []()
+0. [Nyxt](https://nyxt.atlas.engineer/)
+0. [Stack](https://stackbrowser.com/)
+0. [Flow: The super fast, multithreaded HTML5 browser from Ekioh](https://www.ekioh.com/flow-browser/)
+0. https://refresh.study/
+0. https://github.com/breach/breach_core
+0. https://github.com/browserhtml/browserhtml
+0. https://depolium.com/
+0. https://vivaldi.com/
+0. https://www.nidium.com/
+0. https://github.com/trevorlinton/webkit.js
+0. https://www.epicbrowser.com/
+0. https://minbrowser.github.io/min/
+0. https://www.palemoon.org/
+0. https://github.com/beakerbrowser/webdb
+0. https://github.com/beakerbrowser
+0. https://github.com/nEXT-Browser/nEXT
+0. https://techcrunch.com/2018/02/23/veil-is-private-browsing-for-the-ultra-paranoid/
+0. https://github.com/wexond/wexond
+0. http://next.atlas.engineer
+0. https://workona.com/
+0. https://luakit.github.io/
+0. https://www.thurrott.com/cloud/web-browsers/204669/opera-web-browser-is-reborn
 
 # Security
 
-1. https://developers.google.com/web/updates/2018/06/feature-policy
-1. https://cure53.de/#browser-security-whitepaper
-1. https://anon.cosheaf.com/
-1. [Secure Browser Architecture Based on Hardware Virtualization](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.664.9527&rep=rep1&type=pdf)
-1. https://medium.com/personal-capital-tech-blog/why-we-write-post-only-apis-f15108fb6558
+0. []()
+0. https://developers.google.com/web/updates/2018/06/feature-policy
+0. https://cure53.de/#browser-security-whitepaper
+0. https://anon.cosheaf.com/
+0. [Secure Browser Architecture Based on Hardware Virtualization](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.664.9527&rep=rep1&type=pdf)
+0. https://medium.com/personal-capital-tech-blog/why-we-write-post-only-apis-f15108fb6558
 
 # Performance
 
-1. https://github.com/slightlyoff/never_slow_mode
+0. []()
+0. https://github.com/slightlyoff/never_slow_mode
 
 # Reference
 
-1. [Emacs with Nyxt: extend your editor with the power of a Lisp browser](https://nyxt.atlas.engineer/article/emacs-conf.org)
-1. [Web Browser Engineering](https://browser.engineering/)
-1. [Public Suffix List](https://publicsuffix.org/)
-1. [Public Suffix List Problems](https://github.com/sleevi/psl-problems)
-1. https://www.opera.com/gx
-1. https://evertpot.com/tabs-are-the-wrong-abstraction/
-1. http://news.mit.edu/2018/system-patches-private-browsing-0223
-1. https://vivaldi.com/blog/vivaldi-makes-history/?hl=en-us&version=1.8.770.56&os=W10.0.14393
-1. https://hacks.mozilla.org/2017/08/inside-a-super-fast-css-engine-quantum-css-aka-stylo/
-1. https://mozillagfx.wordpress.com/2017/09/21/introduction-to-webrender-part-1-browsers-today/
-1. https://noncombatant.org/2017/11/07/problems-of-urls/
-1. https://stoyannk.wordpress.com/2017/11/13/rendering-html-at-1000-fps-part-2/
-1. https://v8project.blogspot.com/2018/08/embedded-builtins.html
-1. https://developers.google.com/web/updates/2018/09/inside-browser-part1
-1. https://addons.mozilla.org/en-US/firefox/addon/tree-style-tab/
-1. [Web Browser Engineering](https://browser.engineering/index.html)
+0. []()
+0. [V8 Torque user manual](https://v8.dev/docs/torque)
+0. [Emacs with Nyxt: extend your editor with the power of a Lisp browser](https://nyxt.atlas.engineer/article/emacs-conf.org)
+0. [Web Browser Engineering](https://browser.engineering/)
+0. [Public Suffix List](https://publicsuffix.org/)
+0. [Public Suffix List Problems](https://github.com/sleevi/psl-problems)
+0. https://www.opera.com/gx
+0. https://evertpot.com/tabs-are-the-wrong-abstraction/
+0. http://news.mit.edu/2018/system-patches-private-browsing-0223
+0. https://vivaldi.com/blog/vivaldi-makes-history/?hl=en-us&version=1.8.770.56&os=W10.0.14393
+0. https://hacks.mozilla.org/2017/08/inside-a-super-fast-css-engine-quantum-css-aka-stylo/
+0. https://mozillagfx.wordpress.com/2017/09/21/introduction-to-webrender-part-1-browsers-today/
+0. https://noncombatant.org/2017/11/07/problems-of-urls/
+0. https://stoyannk.wordpress.com/2017/11/13/rendering-html-at-1000-fps-part-2/
+0. https://v8project.blogspot.com/2018/08/embedded-builtins.html
+0. https://developers.google.com/web/updates/2018/09/inside-browser-part1
+0. https://addons.mozilla.org/en-US/firefox/addon/tree-style-tab/
+0. [Web Browser Engineering](https://browser.engineering/index.html)
 
diff --git a/stdlib/source/library/lux/control/concurrency/actor.lux b/stdlib/source/library/lux/control/concurrency/actor.lux
index d4c50b896..7b430da17 100644
--- a/stdlib/source/library/lux/control/concurrency/actor.lux
+++ b/stdlib/source/library/lux/control/concurrency/actor.lux
@@ -7,7 +7,9 @@
     ["[0]" pipe]
     ["[0]" try (.only Try)]
     ["[0]" exception]
-    ["[0]" io (.only IO io)]]
+    ["[0]" io (.only IO io)]
+    [function
+     [predicate (.only Predicate)]]]
    [data
     ["[0]" bit]
     ["[0]" product]]
@@ -18,7 +20,7 @@
      [primitive (.only primitive representation abstraction)]]]]]
  [//
   ["[0]" atom (.only Atom atom)]
-  ["[0]" async (.only Async Resolver)]
+  ["[0]" async (.only Async Resolver) (.use "[1]#[0]" monad)]
   ["[0]" frp (.only Channel Channel')]])
 
 (exception.def .public poisoned)
@@ -79,10 +81,11 @@
                                    (when ?state'
                                      {try.#Failure error}
                                      (let [[_ resolve] (the #obituary (representation self))]
-                                       (exec (io.run!
-                                              (do io.monad
-                                                [pending (..pending tail)]
-                                                (resolve [error state {.#Item head pending}])))
+                                       (exec
+                                         (io.run!
+                                          (do io.monad
+                                            [pending (..pending tail)]
+                                            (resolve [error state {.#Item head pending}])))
                                          (in [])))
 
                                      {try.#Success state'}
@@ -170,7 +173,7 @@
                (do async.monad
                  [outcome (async.future (..mail! mail actor))]
                  (when outcome
-                   {try.#Success}
+                   {try.#Success _}
                    async
                    
                    {try.#Failure error}
@@ -209,3 +212,40 @@
                               (at ! each try.maybe))
                           (in {.#None}))))
                     channel)))
+
+... The following behavior and messages allow Lux's actors to behave like Clojure's agents.
+... https://clojure.org/reference/agents
+
+(exception.def .public invalid)
+
+(def .public (validated ? it)
+  (All (_ state)
+    (-> (Predicate state) (Behavior state)
+        (Behavior state)))
+  (function (_ mail before actor)
+    (do (try.with async.monad)
+      [after (mail before actor)]
+      (if (? after)
+        (in after)
+        (async#in (exception.except ..invalid []))))))
+
+(def .public state
+  (All (_ state)
+    (Message state state))
+  (function (_ state self)
+    (async#in {try.#Success [state state]})))
+
+(def .public (update $)
+  (All (_ state)
+    (-> (-> state state)
+        (Message state [state state])))
+  (function (_ before self)
+    (let [after ($ before)]
+      (async#in {try.#Success [after [before after]]}))))
+
+(def .public (reset after)
+  (All (_ state)
+    (-> state
+        (Message state state)))
+  (function (_ before self)
+    (async#in {try.#Success [after before]})))
diff --git a/stdlib/source/library/lux/control/concurrency/agent.lux b/stdlib/source/library/lux/control/concurrency/agent.lux
new file mode 100644
index 000000000..bf9608cb7
--- /dev/null
+++ b/stdlib/source/library/lux/control/concurrency/agent.lux
@@ -0,0 +1,25 @@
+(.require
+ [library
+  [lux (.except)
+   [control
+    ["[0]" try (.only Try)]
+    ["[0]" io (.only IO)]]]]
+ [//
+  ["[0]" async (.only Async)]
+  ["[0]" actor (.only Actor)]
+  ["[0]" frp (.only Channel')]])
+
+(def .public Agent
+  Actor)
+
+(def .public (react! events handler agent)
+  (All (_ eventR eventW state)
+    (-> (Channel' eventR eventW)
+        (-> eventR state (Async (Try state)))
+        (Agent state)
+        (IO Any)))
+  (frp.subscribe! (function (_ event)
+                    (actor.mail! (function (_ state self)
+                                   (handler event state))
+                                 agent))
+                  events))
diff --git a/stdlib/source/test/lux/control.lux b/stdlib/source/test/lux/control.lux
index c51399523..4eba3a2a7 100644
--- a/stdlib/source/test/lux/control.lux
+++ b/stdlib/source/test/lux/control.lux
@@ -7,6 +7,7 @@
   ["[1][0]" concatenative]
   ["[1][0]" concurrency
    ["[1]/[0]" actor]
+   ["[1]/[0]" agent]
    ["[1]/[0]" atom]
    ["[1]/[0]" frp]
    ["[1]/[0]" thread]
@@ -39,6 +40,7 @@
   Test
   (all _.and
        /concurrency/actor.test
+       /concurrency/agent.test
        /concurrency/atom.test
        /concurrency/frp.test
        /concurrency/thread.test
diff --git a/stdlib/source/test/lux/control/concurrency/actor.lux b/stdlib/source/test/lux/control/concurrency/actor.lux
index e8d3568fd..8353b2e8a 100644
--- a/stdlib/source/test/lux/control/concurrency/actor.lux
+++ b/stdlib/source/test/lux/control/concurrency/actor.lux
@@ -200,4 +200,64 @@
                       actual (async.future (atom.read! sink))]
                      (unit.coverage [/.Stop /.observe! /.obituary]
                        (at (list.equivalence n.equivalence) = expected (sequence.list actual))))))
+             (in (do async.monad
+                   [actor (async.future (/.spawn! /.default initial_state))
+                    actual (/.tell! /.state actor)]
+                   (unit.coverage [/.state]
+                     (<| (try.else false)
+                         (do try.monad
+                           [actual actual]
+                           (in (same? initial_state actual)))))))
+             (in (do async.monad
+                   [actor (async.future (/.spawn! /.default initial_state))
+                    before,after (/.tell! (/.update ++) actor)
+                    actual (/.tell! /.state actor)]
+                   (unit.coverage [/.update]
+                     (<| (try.else false)
+                         (do try.monad
+                           [[before after] before,after
+                            actual actual]
+                           (in (and (n.= (++ before) after)
+                                    (same? after actual))))))))
+             (in (do async.monad
+                   [actor (async.future (/.spawn! /.default initial_state))
+                    before,after (/.tell! (/.update ++) actor)
+                    _ (/.tell! (/.reset initial_state) actor)
+                    actual (/.tell! /.state actor)]
+                   (unit.coverage [/.reset]
+                     (<| (try.else false)
+                         (do try.monad
+                           [[before after] before,after
+                            actual actual]
+                           (in (and (n.= (++ before) after)
+                                    (same? initial_state before)
+                                    (same? initial_state actual))))))))
+             (in (do async.monad
+                   [actor (async.future (/.spawn! (/.validated (n.< initial_state) /.default)
+                                                  initial_state))
+                    before,after (/.tell! (/.update --) actor)
+                    actual (/.tell! /.state actor)]
+                   (unit.coverage [/.validated]
+                     (<| (try.else false)
+                         (do try.monad
+                           [[before after] before,after
+                            actual actual]
+                           (in (and (n.= (-- before) after)
+                                    (same? after actual))))))))
+             (in (do async.monad
+                   [actor (async.future (/.spawn! (/.validated (n.< initial_state) /.default)
+                                                  initial_state))
+                    before,after (/.tell! (/.update ++) actor)
+                    [cause_of_death state pending] (/.obituary actor)
+                    actual (/.tell! /.state actor)]
+                   (unit.coverage [/.invalid]
+                     (when [before,after actual]
+                       [{try.#Success [before after]}
+                        {try.#Failure afterwards}]
+                       (and (n.= (++ before) after)
+                            (exception.match? /.invalid cause_of_death)
+                            (exception.match? /.dead afterwards))
+
+                       _
+                       false))))
              ))))
diff --git a/stdlib/source/test/lux/control/concurrency/agent.lux b/stdlib/source/test/lux/control/concurrency/agent.lux
new file mode 100644
index 000000000..9627da9f9
--- /dev/null
+++ b/stdlib/source/test/lux/control/concurrency/agent.lux
@@ -0,0 +1,49 @@
+(.require
+ [library
+  [lux (.except)
+   [abstract
+    [monad (.only do)]]
+   [control
+    ["[0]" try]]
+   [math
+    ["[0]" random]
+    [number
+     ["n" nat]]]
+   [test
+    ["_" property (.only Test)]
+    ["[0]" unit]]]]
+ [\\library
+  ["[0]" / (.only)
+   [//
+    ["[0]" atom (.only Atom)]
+    ["[0]" async (.only Async Resolver) (.use "[1]#[0]" monad)]
+    ["[0]" frp]
+    ["[0]" actor]]]])
+
+(def .public test
+  Test
+  (do [! random.monad]
+    [left random.nat
+     right random.nat]
+    (<| (_.covering /._)
+        (_.for [/.Agent])
+        (all _.and
+             (in (do async.monad
+                   [agent (async.future
+                           (actor.spawn! actor.default 0))
+                    _ (async.future
+                       (/.react! (frp.sequential 0 (list left right))
+                                 (function (_ next current)
+                                   (async#in {try.#Success (n.+ next current)}))
+                                 agent))
+                    _ (async.delay 1)
+                    ?state (actor.tell! actor.state agent)]
+                   (unit.coverage [/.react!]
+                     (when ?state
+                       {try.#Success actual}
+                       (n.= (n.+ left right)
+                            actual)
+                       
+                       failure
+                       false))))
+             ))))