From dc17a715240ee34ed4aaac6c68f3571c5db70aeb Mon Sep 17 00:00:00 2001
From: Taras Mankovski <tarasm@gmail.com>
Date: Thu, 2 May 2019 16:30:41 -0700
Subject: [PATCH 1/5] Added @microstates/lens as a dependency

---
 package.json           |  1 +
 rollup.config.js       |  3 +-
 src/cached-property.js | 13 -------
 src/lens.js            | 83 ------------------------------------------
 src/meta.js            |  2 +-
 src/microstates.js     |  3 +-
 src/pathmap.js         |  3 +-
 src/storage.js         |  2 +-
 src/tree.js            | 27 --------------
 src/types/array.js     |  3 +-
 src/types/object.js    |  2 +-
 tests/lens.test.js     | 25 -------------
 yarn.lock              |  9 ++++-
 13 files changed, 17 insertions(+), 159 deletions(-)
 delete mode 100644 src/cached-property.js
 delete mode 100644 src/lens.js
 delete mode 100644 src/tree.js
 delete mode 100644 tests/lens.test.js

diff --git a/package.json b/package.json
index 13b58eee..1ed258c3 100644
--- a/package.json
+++ b/package.json
@@ -61,6 +61,7 @@
     "rxjs": "^6.2.1"
   },
   "dependencies": {
+    "@microstates/lens": "1.0.0-beta.1",
     "funcadelic": "^0.5.0",
     "symbol-observable": "^1.2.0"
   },
diff --git a/rollup.config.js b/rollup.config.js
index 23dced82..419c63a7 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -7,7 +7,8 @@ const replace = require('rollup-plugin-replace');
 
 const external = [
   "funcadelic",
-  "symbol-observable"
+  "symbol-observable",
+  "@microstates/lens"
 ];
 
 const babelPlugin = babel({
diff --git a/src/cached-property.js b/src/cached-property.js
deleted file mode 100644
index 711c32a4..00000000
--- a/src/cached-property.js
+++ /dev/null
@@ -1,13 +0,0 @@
-export default function CachedProperty(key, reify) {
-  let enumerable = true;
-  let configurable = true;
-  return {
-    enumerable,
-    configurable,
-    get() {
-      let value = reify(this);
-      Object.defineProperty(this, key, { enumerable, value });
-      return value;
-    }
-  };
-}
diff --git a/src/lens.js b/src/lens.js
deleted file mode 100644
index e75e8afe..00000000
--- a/src/lens.js
+++ /dev/null
@@ -1,83 +0,0 @@
-import { Functor, map, Semigroup } from 'funcadelic';
-
-import { childAt } from './tree';
-
-class Box {
-  static get of() {
-    return (...args) => new this(...args);
-  }
-
-  static unwrap(box) {
-    return box.value;
-  }
-
-  constructor(value) {
-    this.value = value;
-  }
-}
-
-const { unwrap } = Box;
-
-class Id extends Box {}
-
-class Const extends Box {}
-
-Functor.instance(Id, {
-  map(fn, id) {
-    return Id.of(fn(id.value));
-  }
-});
-
-Functor.instance(Const, {
-  map(fn, constant) {
-    return constant;
-  }
-});
-
-export function compose(f, g) {
-  return (...x) => f(g(...x));
-}
-
-export function view(lens, context) {
-  let get = compose(unwrap, lens(Const.of));
-  return get(context);
-}
-
-export function over(lens, fn, context) {
-  let update = compose(unwrap, lens(compose(Id.of, fn)));
-  return update(context);
-}
-
-export function set(lens, value, context) {
-  return over(lens, () => value, context);
-}
-
-export function Lens(get, set) {
-  return f => context => {
-    return map(value => set(value, context), f(get(context)));
-  };
-}
-
-export const transparent = Lens(x => x, y => y);
-
-export function At(property, container) {
-  let get = context => context != null ? childAt(property, context) : undefined;
-  let set = (part, whole) => {
-    let context = whole == null ? (Array.isArray(container) ? [] : {}) : whole;
-    if (part === context[property]) {
-      return context;
-    } else if (Array.isArray(context)) {
-      let clone = context.slice();
-      clone[Number(property)] = part;
-      return clone;
-    } else {
-      return Semigroup.for(Object).append(context, {[property]: part});
-    }
-  };
-
-  return Lens(get, set);
-}
-
-export function Path(path) {
-  return path.reduce((lens, key) => compose(lens, At(key)), transparent);
-}
diff --git a/src/meta.js b/src/meta.js
index 805d0f50..87f630e9 100644
--- a/src/meta.js
+++ b/src/meta.js
@@ -1,4 +1,4 @@
-import { At, compose, transparent, over, view } from './lens';
+import { At, compose, transparent, over, view } from '@microstates/lens';
 
 export class Meta {
   static symbol = Symbol('Meta');
diff --git a/src/microstates.js b/src/microstates.js
index 92013f5c..09634ee2 100644
--- a/src/microstates.js
+++ b/src/microstates.js
@@ -1,10 +1,9 @@
 import { append, stable, map } from 'funcadelic';
-import { set } from './lens';
+import { set, CachedProperty } from '@microstates/lens';
 import { Meta, mount, metaOf, valueOf, sourceOf } from './meta';
 import { methodsOf } from './reflection';
 import dsl from './dsl';
 import Any from './types/any';
-import CachedProperty from './cached-property';
 import Observable from './observable';
 
 export function create(InputType = Any, value) {
diff --git a/src/pathmap.js b/src/pathmap.js
index 5941c083..191a4056 100644
--- a/src/pathmap.js
+++ b/src/pathmap.js
@@ -1,8 +1,7 @@
+import { defineChildren, view, Path } from '@microstates/lens';
 import { methodsOf } from './reflection';
 import { create } from './microstates';
-import { view, Path } from './lens';
 import { valueOf, Meta } from './meta';
-import { defineChildren } from './tree';
 import { stable } from 'funcadelic';
 
 import Storage from './storage';
diff --git a/src/storage.js b/src/storage.js
index 980b152f..19b8b406 100644
--- a/src/storage.js
+++ b/src/storage.js
@@ -1,4 +1,4 @@
-import { view, set, Path } from './lens';
+import { view, set, Path } from '@microstates/lens';
 
 export default class Storage {
   constructor(value, observe = x => x) {
diff --git a/src/tree.js b/src/tree.js
deleted file mode 100644
index 7b630cff..00000000
--- a/src/tree.js
+++ /dev/null
@@ -1,27 +0,0 @@
-import { type } from 'funcadelic';
-
-import CachedProperty from './cached-property';
-
-export const Tree = type(class {
-  static name = 'Tree';
-
-  childAt(key, parent) {
-    if (parent[Tree.symbol]) {
-      return this(parent).childAt(key, parent);
-    } else {
-      return parent[key];
-    }
-  }
-
-  defineChildren(fn, parent) {
-    if (parent[Tree.symbol]) {
-      return this(parent).defineChildren(fn, parent);
-    } else {
-      for (let property of Object.keys(parent)) {
-        Object.defineProperty(parent, property, CachedProperty(property, () => fn(property, parent)));
-      }
-    }
-  }
-});
-
-export const { childAt, defineChildren } = Tree.prototype;
diff --git a/src/types/array.js b/src/types/array.js
index f31fbfb9..857a4c5c 100644
--- a/src/types/array.js
+++ b/src/types/array.js
@@ -1,8 +1,7 @@
-import { At, set } from '../lens';
+import { At, set, Tree, childAt } from '@microstates/lens';
 import { mount, valueOf } from '../meta';
 import { create } from '../microstates';
 import parameterized from '../parameterized';
-import { Tree, childAt } from '../tree';
 
 export default parameterized(T => class ArrayType {
   static T = T;
diff --git a/src/types/object.js b/src/types/object.js
index f7518c00..d4a58265 100644
--- a/src/types/object.js
+++ b/src/types/object.js
@@ -1,9 +1,9 @@
 import { append, filter, map } from 'funcadelic';
+import { Tree, childAt } from '@microstates/lens';
 import { reduce, query } from '../query';
 import parameterized from '../parameterized';
 import { valueOf, mount } from '../meta';
 import { create } from '../microstates';
-import { Tree, childAt } from '../tree';
 
 
 export default parameterized(T => class ObjectType {
diff --git a/tests/lens.test.js b/tests/lens.test.js
deleted file mode 100644
index eddfee2a..00000000
--- a/tests/lens.test.js
+++ /dev/null
@@ -1,25 +0,0 @@
-/* global describe, it, beforeEach */
-import expect from 'expect';
-import { compose, view, set, At } from '../src/lens';
-
-describe('At', function() {
-  let lens;
-  beforeEach(function() {
-    lens = compose(At(0, []), At("hello"));
-  });
-
-  it('instantiates objects of the correct type at each path', function() {
-    expect(set(lens, "world", undefined)).toEqual([{hello: 'world'}]);
-  });
-
-  it('set-get: view retrievs what set put in', function() {
-    let cookie = {};
-    let object = set(lens, cookie, undefined);
-    expect(view(lens, object)).toBe(cookie);
-  });
-
-  it('get-set: If you set focus to the same value it has, the whole does not change', function() {
-    let object = set(lens, "world", undefined);
-    expect(set(lens, "world", object)).toBe(object);
-  });
-});
diff --git a/yarn.lock b/yarn.lock
index 23d552be..fbc679fd 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -662,6 +662,13 @@
     "@types/istanbul-lib-coverage" "^1.1.0"
     "@types/yargs" "^12.0.9"
 
+"@microstates/lens@1.0.0-beta.1":
+  version "1.0.0-beta.1"
+  resolved "https://registry.yarnpkg.com/@microstates/lens/-/lens-1.0.0-beta.1.tgz#a94c2d7d0ac409840b70184a8372f9c9c6142655"
+  integrity sha512-qavPeVVnnvqoi6fdWZ7bIfL2eS3+sKAP0qMr/8/tqdYA2Pws6eF2+W9rChYWJa6NUh43tGx/kIAbYFBn3Ztm8A==
+  dependencies:
+    funcadelic "^0.5.7"
+
 "@types/estree@0.0.39":
   version "0.0.39"
   resolved "https://registry.yarnpkg.com/@types/estree/-/estree-0.0.39.tgz#e177e699ee1b8c22d23174caaa7422644389509f"
@@ -1814,7 +1821,7 @@ fs.realpath@^1.0.0:
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
   integrity sha1-FQStJSMVjKpA20onh8sBQRmU6k8=
 
-funcadelic@^0.5.0:
+funcadelic@^0.5.0, funcadelic@^0.5.7:
   version "0.5.7"
   resolved "https://registry.yarnpkg.com/funcadelic/-/funcadelic-0.5.7.tgz#e76f6a9028985531924c1159dc1c930f5b00acb2"
   integrity sha512-kwKSJVAd2FNFmBgku81FC6VJCQdgcT/gtwG9z7H7FxL4NlDKsbdGqLwtjbDlYgR77t+NuT8phBLkmLSKsg1J5w==

From 3992b692882d723ceab0ddb6561407628409bcb4 Mon Sep 17 00:00:00 2001
From: Taras Mankovski <tarasm@gmail.com>
Date: Sat, 11 May 2019 09:06:33 -0400
Subject: [PATCH 2/5] Revert "Added @microstates/lens as a dependency"

This reverts commit dc17a715240ee34ed4aaac6c68f3571c5db70aeb.
---
 package.json           |  1 -
 rollup.config.js       |  3 +-
 src/cached-property.js | 13 +++++++
 src/lens.js            | 83 ++++++++++++++++++++++++++++++++++++++++++
 src/meta.js            |  2 +-
 src/microstates.js     |  3 +-
 src/pathmap.js         |  3 +-
 src/storage.js         |  2 +-
 src/tree.js            | 27 ++++++++++++++
 src/types/array.js     |  3 +-
 src/types/object.js    |  2 +-
 tests/lens.test.js     | 25 +++++++++++++
 yarn.lock              |  9 +----
 13 files changed, 159 insertions(+), 17 deletions(-)
 create mode 100644 src/cached-property.js
 create mode 100644 src/lens.js
 create mode 100644 src/tree.js
 create mode 100644 tests/lens.test.js

diff --git a/package.json b/package.json
index 1ed258c3..13b58eee 100644
--- a/package.json
+++ b/package.json
@@ -61,7 +61,6 @@
     "rxjs": "^6.2.1"
   },
   "dependencies": {
-    "@microstates/lens": "1.0.0-beta.1",
     "funcadelic": "^0.5.0",
     "symbol-observable": "^1.2.0"
   },
diff --git a/rollup.config.js b/rollup.config.js
index 419c63a7..23dced82 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -7,8 +7,7 @@ const replace = require('rollup-plugin-replace');
 
 const external = [
   "funcadelic",
-  "symbol-observable",
-  "@microstates/lens"
+  "symbol-observable"
 ];
 
 const babelPlugin = babel({
diff --git a/src/cached-property.js b/src/cached-property.js
new file mode 100644
index 00000000..711c32a4
--- /dev/null
+++ b/src/cached-property.js
@@ -0,0 +1,13 @@
+export default function CachedProperty(key, reify) {
+  let enumerable = true;
+  let configurable = true;
+  return {
+    enumerable,
+    configurable,
+    get() {
+      let value = reify(this);
+      Object.defineProperty(this, key, { enumerable, value });
+      return value;
+    }
+  };
+}
diff --git a/src/lens.js b/src/lens.js
new file mode 100644
index 00000000..e75e8afe
--- /dev/null
+++ b/src/lens.js
@@ -0,0 +1,83 @@
+import { Functor, map, Semigroup } from 'funcadelic';
+
+import { childAt } from './tree';
+
+class Box {
+  static get of() {
+    return (...args) => new this(...args);
+  }
+
+  static unwrap(box) {
+    return box.value;
+  }
+
+  constructor(value) {
+    this.value = value;
+  }
+}
+
+const { unwrap } = Box;
+
+class Id extends Box {}
+
+class Const extends Box {}
+
+Functor.instance(Id, {
+  map(fn, id) {
+    return Id.of(fn(id.value));
+  }
+});
+
+Functor.instance(Const, {
+  map(fn, constant) {
+    return constant;
+  }
+});
+
+export function compose(f, g) {
+  return (...x) => f(g(...x));
+}
+
+export function view(lens, context) {
+  let get = compose(unwrap, lens(Const.of));
+  return get(context);
+}
+
+export function over(lens, fn, context) {
+  let update = compose(unwrap, lens(compose(Id.of, fn)));
+  return update(context);
+}
+
+export function set(lens, value, context) {
+  return over(lens, () => value, context);
+}
+
+export function Lens(get, set) {
+  return f => context => {
+    return map(value => set(value, context), f(get(context)));
+  };
+}
+
+export const transparent = Lens(x => x, y => y);
+
+export function At(property, container) {
+  let get = context => context != null ? childAt(property, context) : undefined;
+  let set = (part, whole) => {
+    let context = whole == null ? (Array.isArray(container) ? [] : {}) : whole;
+    if (part === context[property]) {
+      return context;
+    } else if (Array.isArray(context)) {
+      let clone = context.slice();
+      clone[Number(property)] = part;
+      return clone;
+    } else {
+      return Semigroup.for(Object).append(context, {[property]: part});
+    }
+  };
+
+  return Lens(get, set);
+}
+
+export function Path(path) {
+  return path.reduce((lens, key) => compose(lens, At(key)), transparent);
+}
diff --git a/src/meta.js b/src/meta.js
index 87f630e9..805d0f50 100644
--- a/src/meta.js
+++ b/src/meta.js
@@ -1,4 +1,4 @@
-import { At, compose, transparent, over, view } from '@microstates/lens';
+import { At, compose, transparent, over, view } from './lens';
 
 export class Meta {
   static symbol = Symbol('Meta');
diff --git a/src/microstates.js b/src/microstates.js
index 09634ee2..92013f5c 100644
--- a/src/microstates.js
+++ b/src/microstates.js
@@ -1,9 +1,10 @@
 import { append, stable, map } from 'funcadelic';
-import { set, CachedProperty } from '@microstates/lens';
+import { set } from './lens';
 import { Meta, mount, metaOf, valueOf, sourceOf } from './meta';
 import { methodsOf } from './reflection';
 import dsl from './dsl';
 import Any from './types/any';
+import CachedProperty from './cached-property';
 import Observable from './observable';
 
 export function create(InputType = Any, value) {
diff --git a/src/pathmap.js b/src/pathmap.js
index 191a4056..5941c083 100644
--- a/src/pathmap.js
+++ b/src/pathmap.js
@@ -1,7 +1,8 @@
-import { defineChildren, view, Path } from '@microstates/lens';
 import { methodsOf } from './reflection';
 import { create } from './microstates';
+import { view, Path } from './lens';
 import { valueOf, Meta } from './meta';
+import { defineChildren } from './tree';
 import { stable } from 'funcadelic';
 
 import Storage from './storage';
diff --git a/src/storage.js b/src/storage.js
index 19b8b406..980b152f 100644
--- a/src/storage.js
+++ b/src/storage.js
@@ -1,4 +1,4 @@
-import { view, set, Path } from '@microstates/lens';
+import { view, set, Path } from './lens';
 
 export default class Storage {
   constructor(value, observe = x => x) {
diff --git a/src/tree.js b/src/tree.js
new file mode 100644
index 00000000..7b630cff
--- /dev/null
+++ b/src/tree.js
@@ -0,0 +1,27 @@
+import { type } from 'funcadelic';
+
+import CachedProperty from './cached-property';
+
+export const Tree = type(class {
+  static name = 'Tree';
+
+  childAt(key, parent) {
+    if (parent[Tree.symbol]) {
+      return this(parent).childAt(key, parent);
+    } else {
+      return parent[key];
+    }
+  }
+
+  defineChildren(fn, parent) {
+    if (parent[Tree.symbol]) {
+      return this(parent).defineChildren(fn, parent);
+    } else {
+      for (let property of Object.keys(parent)) {
+        Object.defineProperty(parent, property, CachedProperty(property, () => fn(property, parent)));
+      }
+    }
+  }
+});
+
+export const { childAt, defineChildren } = Tree.prototype;
diff --git a/src/types/array.js b/src/types/array.js
index 857a4c5c..f31fbfb9 100644
--- a/src/types/array.js
+++ b/src/types/array.js
@@ -1,7 +1,8 @@
-import { At, set, Tree, childAt } from '@microstates/lens';
+import { At, set } from '../lens';
 import { mount, valueOf } from '../meta';
 import { create } from '../microstates';
 import parameterized from '../parameterized';
+import { Tree, childAt } from '../tree';
 
 export default parameterized(T => class ArrayType {
   static T = T;
diff --git a/src/types/object.js b/src/types/object.js
index d4a58265..f7518c00 100644
--- a/src/types/object.js
+++ b/src/types/object.js
@@ -1,9 +1,9 @@
 import { append, filter, map } from 'funcadelic';
-import { Tree, childAt } from '@microstates/lens';
 import { reduce, query } from '../query';
 import parameterized from '../parameterized';
 import { valueOf, mount } from '../meta';
 import { create } from '../microstates';
+import { Tree, childAt } from '../tree';
 
 
 export default parameterized(T => class ObjectType {
diff --git a/tests/lens.test.js b/tests/lens.test.js
new file mode 100644
index 00000000..eddfee2a
--- /dev/null
+++ b/tests/lens.test.js
@@ -0,0 +1,25 @@
+/* global describe, it, beforeEach */
+import expect from 'expect';
+import { compose, view, set, At } from '../src/lens';
+
+describe('At', function() {
+  let lens;
+  beforeEach(function() {
+    lens = compose(At(0, []), At("hello"));
+  });
+
+  it('instantiates objects of the correct type at each path', function() {
+    expect(set(lens, "world", undefined)).toEqual([{hello: 'world'}]);
+  });
+
+  it('set-get: view retrievs what set put in', function() {
+    let cookie = {};
+    let object = set(lens, cookie, undefined);
+    expect(view(lens, object)).toBe(cookie);
+  });
+
+  it('get-set: If you set focus to the same value it has, the whole does not change', function() {
+    let object = set(lens, "world", undefined);
+    expect(set(lens, "world", object)).toBe(object);
+  });
+});
diff --git a/yarn.lock b/yarn.lock
index fbc679fd..23d552be 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -662,13 +662,6 @@
     "@types/istanbul-lib-coverage" "^1.1.0"
     "@types/yargs" "^12.0.9"
 
-"@microstates/lens@1.0.0-beta.1":
-  version "1.0.0-beta.1"
-  resolved "https://registry.yarnpkg.com/@microstates/lens/-/lens-1.0.0-beta.1.tgz#a94c2d7d0ac409840b70184a8372f9c9c6142655"
-  integrity sha512-qavPeVVnnvqoi6fdWZ7bIfL2eS3+sKAP0qMr/8/tqdYA2Pws6eF2+W9rChYWJa6NUh43tGx/kIAbYFBn3Ztm8A==
-  dependencies:
-    funcadelic "^0.5.7"
-
 "@types/estree@0.0.39":
   version "0.0.39"
   resolved "https://registry.yarnpkg.com/@types/estree/-/estree-0.0.39.tgz#e177e699ee1b8c22d23174caaa7422644389509f"
@@ -1821,7 +1814,7 @@ fs.realpath@^1.0.0:
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
   integrity sha1-FQStJSMVjKpA20onh8sBQRmU6k8=
 
-funcadelic@^0.5.0, funcadelic@^0.5.7:
+funcadelic@^0.5.0:
   version "0.5.7"
   resolved "https://registry.yarnpkg.com/funcadelic/-/funcadelic-0.5.7.tgz#e76f6a9028985531924c1159dc1c930f5b00acb2"
   integrity sha512-kwKSJVAd2FNFmBgku81FC6VJCQdgcT/gtwG9z7H7FxL4NlDKsbdGqLwtjbDlYgR77t+NuT8phBLkmLSKsg1J5w==

From a0961da7186c817684ff82bf0556a0b9950caed0 Mon Sep 17 00:00:00 2001
From: Taras Mankovski <tarasm@gmail.com>
Date: Sat, 11 May 2019 09:08:19 -0400
Subject: [PATCH 3/5] Add @microstates/lens@1.0.0-beta.2

---
 package.json | 1 +
 yarn.lock    | 9 ++++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 13b58eee..8f826ec0 100644
--- a/package.json
+++ b/package.json
@@ -61,6 +61,7 @@
     "rxjs": "^6.2.1"
   },
   "dependencies": {
+    "@microstates/lens": "1.0.0-beta.2",
     "funcadelic": "^0.5.0",
     "symbol-observable": "^1.2.0"
   },
diff --git a/yarn.lock b/yarn.lock
index 23d552be..f0896c14 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -662,6 +662,13 @@
     "@types/istanbul-lib-coverage" "^1.1.0"
     "@types/yargs" "^12.0.9"
 
+"@microstates/lens@1.0.0-beta.2":
+  version "1.0.0-beta.2"
+  resolved "https://registry.yarnpkg.com/@microstates/lens/-/lens-1.0.0-beta.2.tgz#b43badbe038a90f95f13f4ae57a34fddd380c356"
+  integrity sha512-WrPBgPut3h8c7/Yl1tIaA8Fw4TV80mx3EXJGvumBhx15GE+z31HB+31loz9+I4dbGq6xC4Xi7rhMXdiBqRK6Ug==
+  dependencies:
+    funcadelic "^0.5.7"
+
 "@types/estree@0.0.39":
   version "0.0.39"
   resolved "https://registry.yarnpkg.com/@types/estree/-/estree-0.0.39.tgz#e177e699ee1b8c22d23174caaa7422644389509f"
@@ -1814,7 +1821,7 @@ fs.realpath@^1.0.0:
   resolved "https://registry.yarnpkg.com/fs.realpath/-/fs.realpath-1.0.0.tgz#1504ad2523158caa40db4a2787cb01411994ea4f"
   integrity sha1-FQStJSMVjKpA20onh8sBQRmU6k8=
 
-funcadelic@^0.5.0:
+funcadelic@^0.5.0, funcadelic@^0.5.7:
   version "0.5.7"
   resolved "https://registry.yarnpkg.com/funcadelic/-/funcadelic-0.5.7.tgz#e76f6a9028985531924c1159dc1c930f5b00acb2"
   integrity sha512-kwKSJVAd2FNFmBgku81FC6VJCQdgcT/gtwG9z7H7FxL4NlDKsbdGqLwtjbDlYgR77t+NuT8phBLkmLSKsg1J5w==

From 44d1c9ac6e29b7416bcfb7dacef931473c39c2f0 Mon Sep 17 00:00:00 2001
From: Taras Mankovski <tarasm@gmail.com>
Date: Sat, 11 May 2019 09:19:23 -0400
Subject: [PATCH 4/5] Refactor to use lens from @microstates/lens

---
 rollup.config.js    |  3 +-
 src/lens.js         | 83 ---------------------------------------------
 src/meta.js         |  2 +-
 src/microstates.js  |  2 +-
 src/pathmap.js      |  2 +-
 src/storage.js      |  2 +-
 src/tree.js         | 10 +-----
 src/types/array.js  | 14 ++++----
 src/types/object.js | 16 +++++----
 tests/lens.test.js  | 25 --------------
 10 files changed, 25 insertions(+), 134 deletions(-)
 delete mode 100644 src/lens.js
 delete mode 100644 tests/lens.test.js

diff --git a/rollup.config.js b/rollup.config.js
index 23dced82..419c63a7 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -7,7 +7,8 @@ const replace = require('rollup-plugin-replace');
 
 const external = [
   "funcadelic",
-  "symbol-observable"
+  "symbol-observable",
+  "@microstates/lens"
 ];
 
 const babelPlugin = babel({
diff --git a/src/lens.js b/src/lens.js
deleted file mode 100644
index e75e8afe..00000000
--- a/src/lens.js
+++ /dev/null
@@ -1,83 +0,0 @@
-import { Functor, map, Semigroup } from 'funcadelic';
-
-import { childAt } from './tree';
-
-class Box {
-  static get of() {
-    return (...args) => new this(...args);
-  }
-
-  static unwrap(box) {
-    return box.value;
-  }
-
-  constructor(value) {
-    this.value = value;
-  }
-}
-
-const { unwrap } = Box;
-
-class Id extends Box {}
-
-class Const extends Box {}
-
-Functor.instance(Id, {
-  map(fn, id) {
-    return Id.of(fn(id.value));
-  }
-});
-
-Functor.instance(Const, {
-  map(fn, constant) {
-    return constant;
-  }
-});
-
-export function compose(f, g) {
-  return (...x) => f(g(...x));
-}
-
-export function view(lens, context) {
-  let get = compose(unwrap, lens(Const.of));
-  return get(context);
-}
-
-export function over(lens, fn, context) {
-  let update = compose(unwrap, lens(compose(Id.of, fn)));
-  return update(context);
-}
-
-export function set(lens, value, context) {
-  return over(lens, () => value, context);
-}
-
-export function Lens(get, set) {
-  return f => context => {
-    return map(value => set(value, context), f(get(context)));
-  };
-}
-
-export const transparent = Lens(x => x, y => y);
-
-export function At(property, container) {
-  let get = context => context != null ? childAt(property, context) : undefined;
-  let set = (part, whole) => {
-    let context = whole == null ? (Array.isArray(container) ? [] : {}) : whole;
-    if (part === context[property]) {
-      return context;
-    } else if (Array.isArray(context)) {
-      let clone = context.slice();
-      clone[Number(property)] = part;
-      return clone;
-    } else {
-      return Semigroup.for(Object).append(context, {[property]: part});
-    }
-  };
-
-  return Lens(get, set);
-}
-
-export function Path(path) {
-  return path.reduce((lens, key) => compose(lens, At(key)), transparent);
-}
diff --git a/src/meta.js b/src/meta.js
index 805d0f50..87f630e9 100644
--- a/src/meta.js
+++ b/src/meta.js
@@ -1,4 +1,4 @@
-import { At, compose, transparent, over, view } from './lens';
+import { At, compose, transparent, over, view } from '@microstates/lens';
 
 export class Meta {
   static symbol = Symbol('Meta');
diff --git a/src/microstates.js b/src/microstates.js
index 92013f5c..dd2e310a 100644
--- a/src/microstates.js
+++ b/src/microstates.js
@@ -1,5 +1,5 @@
 import { append, stable, map } from 'funcadelic';
-import { set } from './lens';
+import { set } from '@microstates/lens';
 import { Meta, mount, metaOf, valueOf, sourceOf } from './meta';
 import { methodsOf } from './reflection';
 import dsl from './dsl';
diff --git a/src/pathmap.js b/src/pathmap.js
index 5941c083..dc54e98f 100644
--- a/src/pathmap.js
+++ b/src/pathmap.js
@@ -1,6 +1,6 @@
+import { view, Path } from '@microstates/lens';
 import { methodsOf } from './reflection';
 import { create } from './microstates';
-import { view, Path } from './lens';
 import { valueOf, Meta } from './meta';
 import { defineChildren } from './tree';
 import { stable } from 'funcadelic';
diff --git a/src/storage.js b/src/storage.js
index 980b152f..19b8b406 100644
--- a/src/storage.js
+++ b/src/storage.js
@@ -1,4 +1,4 @@
-import { view, set, Path } from './lens';
+import { view, set, Path } from '@microstates/lens';
 
 export default class Storage {
   constructor(value, observe = x => x) {
diff --git a/src/tree.js b/src/tree.js
index 7b630cff..e3126fa9 100644
--- a/src/tree.js
+++ b/src/tree.js
@@ -5,14 +5,6 @@ import CachedProperty from './cached-property';
 export const Tree = type(class {
   static name = 'Tree';
 
-  childAt(key, parent) {
-    if (parent[Tree.symbol]) {
-      return this(parent).childAt(key, parent);
-    } else {
-      return parent[key];
-    }
-  }
-
   defineChildren(fn, parent) {
     if (parent[Tree.symbol]) {
       return this(parent).defineChildren(fn, parent);
@@ -24,4 +16,4 @@ export const Tree = type(class {
   }
 });
 
-export const { childAt, defineChildren } = Tree.prototype;
+export const { defineChildren } = Tree.prototype;
diff --git a/src/types/array.js b/src/types/array.js
index f31fbfb9..0d5415af 100644
--- a/src/types/array.js
+++ b/src/types/array.js
@@ -1,8 +1,8 @@
-import { At, set } from '../lens';
+import { at, At, set, Context } from '@microstates/lens'
 import { mount, valueOf } from '../meta';
 import { create } from '../microstates';
 import parameterized from '../parameterized';
-import { Tree, childAt } from '../tree';
+import { Tree } from '../tree';
 
 export default parameterized(T => class ArrayType {
   static T = T;
@@ -88,7 +88,7 @@ export default parameterized(T => class ArrayType {
           get done() { return next.done; },
           get value() {
             if (!next.done) {
-              return childAt(index, array);
+              return at(index, array);
             } else {
               return undefined;
             }
@@ -100,16 +100,18 @@ export default parameterized(T => class ArrayType {
 
   static initialize() {
 
-    Tree.instance(this, {
-      childAt(key, array) {
+    Context.instance(this, {
+      at(key, array) {
         if (typeof key === 'number') {
           let value = valueOf(array)[key];
           return mount(array, create(T, value), key);
         } else {
           return array[key];
         }
-      },
+      }
+    })
 
+    Tree.instance(this, {
       defineChildren(fn, array) {
         let generate = array[Symbol.iterator];
         return Object.defineProperty(array, Symbol.iterator, {
diff --git a/src/types/object.js b/src/types/object.js
index f7518c00..f51f9ded 100644
--- a/src/types/object.js
+++ b/src/types/object.js
@@ -1,10 +1,10 @@
 import { append, filter, map } from 'funcadelic';
+import { at, Context } from '@microstates/lens';
 import { reduce, query } from '../query';
 import parameterized from '../parameterized';
 import { valueOf, mount } from '../meta';
 import { create } from '../microstates';
-import { Tree, childAt } from '../tree';
-
+import { Tree } from '../tree';
 
 export default parameterized(T => class ObjectType {
   static T = T;
@@ -59,7 +59,7 @@ export default parameterized(T => class ObjectType {
           get done() { return next.done; },
           get value() {
             if (!next.done) {
-              return new Entry(next.value, childAt(next.value, object));
+              return new Entry(next.value, at(next.value, object));
             } else {
               return undefined;
             }
@@ -70,15 +70,19 @@ export default parameterized(T => class ObjectType {
   }
 
   static initialize() {
-    Tree.instance(this, {
-      childAt(key, object) {
+
+    Context.instance(this, {
+      at(key, object) {
         if (typeof key !== 'string') {
           return object[key];
         } else {
           let value = valueOf(object)[key];
           return mount(object, create(T, value), key);
         }
-      },
+      }
+    })
+
+    Tree.instance(this, {
       defineChildren(fn, object) {
         let generate = object[Symbol.iterator];
         return Object.defineProperty(object, Symbol.iterator, {
diff --git a/tests/lens.test.js b/tests/lens.test.js
deleted file mode 100644
index eddfee2a..00000000
--- a/tests/lens.test.js
+++ /dev/null
@@ -1,25 +0,0 @@
-/* global describe, it, beforeEach */
-import expect from 'expect';
-import { compose, view, set, At } from '../src/lens';
-
-describe('At', function() {
-  let lens;
-  beforeEach(function() {
-    lens = compose(At(0, []), At("hello"));
-  });
-
-  it('instantiates objects of the correct type at each path', function() {
-    expect(set(lens, "world", undefined)).toEqual([{hello: 'world'}]);
-  });
-
-  it('set-get: view retrievs what set put in', function() {
-    let cookie = {};
-    let object = set(lens, cookie, undefined);
-    expect(view(lens, object)).toBe(cookie);
-  });
-
-  it('get-set: If you set focus to the same value it has, the whole does not change', function() {
-    let object = set(lens, "world", undefined);
-    expect(set(lens, "world", object)).toBe(object);
-  });
-});

From 8f70c54f301160177bbe6820815a6fd7ea116773 Mon Sep 17 00:00:00 2001
From: Taras Mankovski <tarasm@gmail.com>
Date: Sat, 11 May 2019 09:21:37 -0400
Subject: [PATCH 5/5] Fixed lint errors

---
 src/types/array.js  | 4 ++--
 src/types/object.js | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/types/array.js b/src/types/array.js
index 0d5415af..ad368d05 100644
--- a/src/types/array.js
+++ b/src/types/array.js
@@ -1,4 +1,4 @@
-import { at, At, set, Context } from '@microstates/lens'
+import { at, At, set, Context } from '@microstates/lens';
 import { mount, valueOf } from '../meta';
 import { create } from '../microstates';
 import parameterized from '../parameterized';
@@ -109,7 +109,7 @@ export default parameterized(T => class ArrayType {
           return array[key];
         }
       }
-    })
+    });
 
     Tree.instance(this, {
       defineChildren(fn, array) {
diff --git a/src/types/object.js b/src/types/object.js
index f51f9ded..9e2df766 100644
--- a/src/types/object.js
+++ b/src/types/object.js
@@ -80,7 +80,7 @@ export default parameterized(T => class ObjectType {
           return mount(object, create(T, value), key);
         }
       }
-    })
+    });
 
     Tree.instance(this, {
       defineChildren(fn, object) {