From 9d7c3c2adbf9eccb9e4bab4cd375186de90a1c11 Mon Sep 17 00:00:00 2001
From: Mike Bostock <mbostock@gmail.com>
Date: Tue, 19 Nov 2019 09:37:17 -0800
Subject: [PATCH 01/16] Allow stack.{keys,order} to be iterable.

---
 src/stack.js | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/stack.js b/src/stack.js
index ab4008e..756163c 100644
--- a/src/stack.js
+++ b/src/stack.js
@@ -1,4 +1,3 @@
-import {slice} from "./array.js";
 import constant from "./constant.js";
 import offsetNone from "./offset/none.js";
 import orderNone from "./order/none.js";
@@ -38,7 +37,7 @@ export default function() {
   }
 
   stack.keys = function(_) {
-    return arguments.length ? (keys = typeof _ === "function" ? _ : constant(slice.call(_)), stack) : keys;
+    return arguments.length ? (keys = typeof _ === "function" ? _ : constant(Array.from(_)), stack) : keys;
   };
 
   stack.value = function(_) {
@@ -46,7 +45,7 @@ export default function() {
   };
 
   stack.order = function(_) {
-    return arguments.length ? (order = _ == null ? orderNone : typeof _ === "function" ? _ : constant(slice.call(_)), stack) : order;
+    return arguments.length ? (order = _ == null ? orderNone : typeof _ === "function" ? _ : constant(Array.from(_)), stack) : order;
   };
 
   stack.offset = function(_) {

From 5a4e7929c4ea8865e4d7591274a16cdd2416008d Mon Sep 17 00:00:00 2001
From: Mike Bostock <mbostock@gmail.com>
Date: Tue, 19 Nov 2019 09:49:56 -0800
Subject: [PATCH 02/16] Accept iterable for stack.

---
 src/stack.js | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/stack.js b/src/stack.js
index 756163c..68815ef 100644
--- a/src/stack.js
+++ b/src/stack.js
@@ -6,6 +6,12 @@ function stackValue(d, key) {
   return d[key];
 }
 
+function stackSeries(key) {
+  const series = [];
+  series.key = key;
+  return series;
+}
+
 export default function() {
   var keys = constant([]),
       order = orderNone,
@@ -14,18 +20,14 @@ export default function() {
 
   function stack(data) {
     var kz = keys.apply(this, arguments),
-        i,
-        m = data.length,
-        n = kz.length,
-        sz = new Array(n),
+        sz = kz.map(stackSeries),
+        i, n = sz.length, m = -1,
         oz;
 
-    for (i = 0; i < n; ++i) {
-      for (var ki = kz[i], si = sz[i] = new Array(m), j = 0, sij; j < m; ++j) {
-        si[j] = sij = [0, +value(data[j], ki, j, data)];
-        sij.data = data[j];
+    for (const d of data) {
+      for (i = 0, ++m; i < n; ++i) {
+        (sz[i][m] = [0, +value(d, kz[i], m, data)]).data = d;
       }
-      si.key = ki;
     }
 
     for (i = 0, oz = order(sz); i < n; ++i) {

From 32221b2fca3da201bd18adfb288c7952af826a6d Mon Sep 17 00:00:00 2001
From: Mike Bostock <mbostock@gmail.com>
Date: Tue, 19 Nov 2019 09:51:20 -0800
Subject: [PATCH 03/16] Rename.

---
 src/stack.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/stack.js b/src/stack.js
index 68815ef..e5a849b 100644
--- a/src/stack.js
+++ b/src/stack.js
@@ -21,12 +21,12 @@ export default function() {
   function stack(data) {
     var kz = keys.apply(this, arguments),
         sz = kz.map(stackSeries),
-        i, n = sz.length, m = -1,
+        i, n = sz.length, j = -1,
         oz;
 
     for (const d of data) {
-      for (i = 0, ++m; i < n; ++i) {
-        (sz[i][m] = [0, +value(d, kz[i], m, data)]).data = d;
+      for (i = 0, ++j; i < n; ++i) {
+        (sz[i][j] = [0, +value(d, kz[i], j, data)]).data = d;
       }
     }
 

From 3c9bd9ea7318f4aa416f622219826fba774cf9f8 Mon Sep 17 00:00:00 2001
From: Mike Bostock <mbostock@gmail.com>
Date: Tue, 19 Nov 2019 09:57:05 -0800
Subject: [PATCH 04/16] Allow stack.keys function to return an iterable.

---
 src/stack.js | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/stack.js b/src/stack.js
index e5a849b..592429f 100644
--- a/src/stack.js
+++ b/src/stack.js
@@ -19,14 +19,13 @@ export default function() {
       value = stackValue;
 
   function stack(data) {
-    var kz = keys.apply(this, arguments),
-        sz = kz.map(stackSeries),
+    var sz = Array.from(keys.apply(this, arguments), stackSeries),
         i, n = sz.length, j = -1,
         oz;
 
     for (const d of data) {
       for (i = 0, ++j; i < n; ++i) {
-        (sz[i][j] = [0, +value(d, kz[i], j, data)]).data = d;
+        (sz[i][j] = [0, +value(d, sz[i].key, j, data)]).data = d;
       }
     }
 

From e3337dd212a18586f881e1427e03d0870ecadb36 Mon Sep 17 00:00:00 2001
From: Mike Bostock <mbostock@gmail.com>
Date: Tue, 19 Nov 2019 10:02:31 -0800
Subject: [PATCH 05/16] Allow stack.order function to return an iterable.

---
 src/stack.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/stack.js b/src/stack.js
index 592429f..6c3742d 100644
--- a/src/stack.js
+++ b/src/stack.js
@@ -29,7 +29,7 @@ export default function() {
       }
     }
 
-    for (i = 0, oz = order(sz); i < n; ++i) {
+    for (i = 0, oz = Array.from(order(sz)); i < n; ++i) {
       sz[oz[i]].index = i;
     }
 

From 061a6a58f012251f504201a6bfc957aefde6ec05 Mon Sep 17 00:00:00 2001
From: Mike Bostock <mbostock@gmail.com>
Date: Tue, 19 Nov 2019 10:06:03 -0800
Subject: [PATCH 06/16] Allow pie, line, and area to take iterables.

---
 src/area.js  | 3 ++-
 src/array.js | 6 ++++++
 src/line.js  | 3 ++-
 src/pie.js   | 3 ++-
 src/stack.js | 3 ++-
 5 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/area.js b/src/area.js
index a048a01..9fe3db8 100644
--- a/src/area.js
+++ b/src/area.js
@@ -1,4 +1,5 @@
 import {path} from "d3-path";
+import array from "./array.js";
 import constant from "./constant.js";
 import curveLinear from "./curve/linear.js";
 import line from "./line.js";
@@ -18,7 +19,7 @@ export default function() {
     var i,
         j,
         k,
-        n = data.length,
+        n = (data = array(data)).length,
         d,
         defined0 = false,
         buffer,
diff --git a/src/array.js b/src/array.js
index 8eeac16..90808ff 100644
--- a/src/array.js
+++ b/src/array.js
@@ -1 +1,7 @@
 export var slice = Array.prototype.slice;
+
+export default function(x) {
+  return typeof x === "object" && "length" in x
+    ? x // Array, TypedArray, NodeList, array-like
+    : Array.from(x); // Map, Set, iterable, string, or anything else
+}
diff --git a/src/line.js b/src/line.js
index 3ba2ab3..ba3ae15 100644
--- a/src/line.js
+++ b/src/line.js
@@ -1,4 +1,5 @@
 import {path} from "d3-path";
+import array from "./array.js";
 import constant from "./constant.js";
 import curveLinear from "./curve/linear.js";
 import {x as pointX, y as pointY} from "./point.js";
@@ -13,7 +14,7 @@ export default function() {
 
   function line(data) {
     var i,
-        n = data.length,
+        n = (data = array(data)).length,
         d,
         defined0 = false,
         buffer;
diff --git a/src/pie.js b/src/pie.js
index 1108722..6748f45 100644
--- a/src/pie.js
+++ b/src/pie.js
@@ -1,3 +1,4 @@
+import array from "./array.js";
 import constant from "./constant.js";
 import descending from "./descending.js";
 import identity from "./identity.js";
@@ -13,7 +14,7 @@ export default function() {
 
   function pie(data) {
     var i,
-        n = data.length,
+        n = (data = array(data)).length,
         j,
         k,
         sum = 0,
diff --git a/src/stack.js b/src/stack.js
index 6c3742d..c4d30b1 100644
--- a/src/stack.js
+++ b/src/stack.js
@@ -1,3 +1,4 @@
+import array from "./array.js";
 import constant from "./constant.js";
 import offsetNone from "./offset/none.js";
 import orderNone from "./order/none.js";
@@ -29,7 +30,7 @@ export default function() {
       }
     }
 
-    for (i = 0, oz = Array.from(order(sz)); i < n; ++i) {
+    for (i = 0, oz = array(order(sz)); i < n; ++i) {
       sz[oz[i]].index = i;
     }
 

From 3672c0112fa2597e52cc942cf95386558fb0af1f Mon Sep 17 00:00:00 2001
From: Mike Bostock <mbostock@gmail.com>
Date: Tue, 19 Nov 2019 10:06:48 -0800
Subject: [PATCH 07/16] Test for pie(iterable).

---
 test/pie-test.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/test/pie-test.js b/test/pie-test.js
index 0a4aaa8..e952e60 100644
--- a/test/pie-test.js
+++ b/test/pie-test.js
@@ -24,6 +24,16 @@ tape("pie(data) returns arcs in input order", function(test) {
   test.end();
 });
 
+tape("pie(data) accepts an iterable", function(test) {
+  var p = shape.pie();
+  test.deepEqual(p(new Set([1, 3, 2])), [
+    {data: 1, value: 1, index: 2, startAngle: 5.235987755982988, endAngle: 6.283185307179585, padAngle: 0},
+    {data: 3, value: 3, index: 0, startAngle: 0.000000000000000, endAngle: 3.141592653589793, padAngle: 0},
+    {data: 2, value: 2, index: 1, startAngle: 3.141592653589793, endAngle: 5.235987755982988, padAngle: 0}
+  ]);
+  test.end();
+});
+
 tape("pie(data) coerces the specified value to a number", function(test) {
   var p = shape.pie(), three = {valueOf: function() { return 3; }};
   test.deepEqual(p(["1", three, "2"]), [

From 7651a1aba6b9e3fa7d1d202a8c4f5e84e1f6d50f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Rivi=C3=A8re?= <fil@rezo.net>
Date: Fri, 10 Jul 2020 21:57:38 +0200
Subject: [PATCH 08/16] links to d3v6 versions

---
 README.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 70783d0..9645d84 100644
--- a/README.md
+++ b/README.md
@@ -26,11 +26,11 @@ For more, read [Introducing d3-shape](https://medium.com/@mbostock/introducing-d
 
 ## Installing
 
-If you use NPM, `npm install d3-shape`. Otherwise, download the [latest release](https://github.com/d3/d3-shape/releases/latest). You can also load directly from [d3js.org](https://d3js.org), either as a [standalone library](https://d3js.org/d3-shape.v1.min.js) or as part of [D3](https://github.com/d3/d3). AMD, CommonJS, and vanilla environments are supported. In vanilla, a `d3` global is exported:
+If you use NPM, `npm install d3-shape`. Otherwise, download the [latest release](https://github.com/d3/d3-shape/releases/latest). You can also load directly from [d3js.org](https://d3js.org), either as a [standalone library](https://d3js.org/d3-shape.v2.min.js) or as part of [D3](https://github.com/d3/d3). AMD, CommonJS, and vanilla environments are supported. In vanilla, a `d3` global is exported:
 
 ```html
-<script src="https://d3js.org/d3-path.v1.min.js"></script>
-<script src="https://d3js.org/d3-shape.v1.min.js"></script>
+<script src="https://d3js.org/d3-path.v2.min.js"></script>
+<script src="https://d3js.org/d3-shape.v2.min.js"></script>
 <script>
 
 var line = d3.line();

From 4364ddc62f1f4ed08a7f154bdaef8e2935d47d63 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Rivi=C3=A8re?= <fil@rezo.net>
Date: Fri, 10 Jul 2020 21:57:45 +0200
Subject: [PATCH 09/16] note about iterables

---
 README.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/README.md b/README.md
index 9645d84..4b54341 100644
--- a/README.md
+++ b/README.md
@@ -52,6 +52,8 @@ var line = d3.line();
 * [Custom Symbol Types](#custom-symbol-types)
 * [Stacks](#stacks)
 
+Note: all the methods that accept arrays also accept iterables and convert them to arrays internally.
+
 ### Arcs
 
 [<img alt="Pie Chart" src="https://raw.githubusercontent.com/d3/d3-shape/master/img/pie.png" width="295" height="295">](http://bl.ocks.org/mbostock/8878e7fd82034f1d63cf)[<img alt="Donut Chart" src="https://raw.githubusercontent.com/d3/d3-shape/master/img/donut.png" width="295" height="295">](http://bl.ocks.org/mbostock/2394b23da1994fc202e1)

From 42c149350e9e3c3ed5bb4f6a49fc7c812bac1e33 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Rivi=C3=A8re?= <fil@rezo.net>
Date: Fri, 17 Jul 2020 18:16:38 +0200
Subject: [PATCH 10/16] d3.line(x,y) and d3.are(x,y0,y1) shorthand notations

fixes #159
---
 README.md         |  8 ++++----
 src/area.js       | 11 ++++++-----
 src/line.js       |  9 +++++----
 test/area-test.js | 11 +++++++++++
 test/line-test.js |  9 +++++++++
 5 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/README.md b/README.md
index 4b54341..37e044d 100644
--- a/README.md
+++ b/README.md
@@ -351,9 +351,9 @@ The pad angle here means the angular separation between each adjacent arc. The t
 
 The line generator produces a [spline](https://en.wikipedia.org/wiki/Spline_\(mathematics\)) or [polyline](https://en.wikipedia.org/wiki/Polygonal_chain), as in a line chart. Lines also appear in many other visualization types, such as the links in [hierarchical edge bundling](https://observablehq.com/@d3/hierarchical-edge-bundling).
 
-<a name="line" href="#line">#</a> d3.<b>line</b>() · [Source](https://github.com/d3/d3-shape/blob/master/src/line.js), [Examples](https://observablehq.com/@d3/d3-line)
+<a name="line" href="#line">#</a> d3.<b>line</b>([<i>x</i>][, <i>y</i>]) · [Source](https://github.com/d3/d3-shape/blob/master/src/line.js), [Examples](https://observablehq.com/@d3/d3-line)
 
-Constructs a new line generator with the default settings.
+Constructs a new line generator with the default settings. If *x* or *y* are specified, sets the corresponding accessors to the specified function or number and returns this line generator.
 
 <a name="_line" href="#_line">#</a> <i>line</i>(<i>data</i>) · [Source](https://github.com/d3/d3-shape/blob/master/src/line.js), [Examples](https://observablehq.com/@d3/d3-line)
 
@@ -459,9 +459,9 @@ Equivalent to [*line*.context](#line_context).
 
 The area generator produces an area, as in an area chart. An area is defined by two bounding [lines](#lines), either splines or polylines. Typically, the two lines share the same [*x*-values](#area_x) ([x0](#area_x0) = [x1](#area_x1)), differing only in *y*-value ([y0](#area_y0) and [y1](#area_y1)); most commonly, y0 is defined as a constant representing [zero](http://www.vox.com/2015/11/19/9758062/y-axis-zero-chart). The first line (the <i>topline</i>) is defined by x1 and y1 and is rendered first; the second line (the <i>baseline</i>) is defined by x0 and y0 and is rendered second, with the points in reverse order. With a [curveLinear](#curveLinear) [curve](#area_curve), this produces a clockwise polygon.
 
-<a name="area" href="#area">#</a> d3.<b>area</b>() · [Source](https://github.com/d3/d3-shape/blob/master/src/area.js)
+<a name="area" href="#area">#</a> d3.<b>area</b>([<i>x</i>][, <i>y0</i>][, <i>y1</i>]) · [Source](https://github.com/d3/d3-shape/blob/master/src/area.js)
 
-Constructs a new area generator with the default settings.
+Constructs a new area generator with the default settings. If *x*, *y0* or *y1* are specified, sets the corresponding accessors to the specified function or number and returns this area generator.
 
 <a name="_area" href="#_area">#</a> <i>area</i>(<i>data</i>) · [Source](https://github.com/d3/d3-shape/blob/master/src/area.js)
 
diff --git a/src/area.js b/src/area.js
index 9fe3db8..8726630 100644
--- a/src/area.js
+++ b/src/area.js
@@ -5,16 +5,17 @@ import curveLinear from "./curve/linear.js";
 import line from "./line.js";
 import {x as pointX, y as pointY} from "./point.js";
 
-export default function() {
-  var x0 = pointX,
-      x1 = null,
-      y0 = constant(0),
-      y1 = pointY,
+export default function(x0, y0, y1) {
+  var x1 = null,
       defined = constant(true),
       context = null,
       curve = curveLinear,
       output = null;
 
+  x0 = typeof x0 === "function" ? x0 : (x0 === undefined) ? pointX : constant(+x0);
+  y0 = typeof y0 === "function" ? y0 : (y0 === undefined) ? constant(0) : constant(+y0);
+  y1 = typeof y1 === "function" ? y1 : (y1 === undefined) ? pointY : constant(+y1);
+
   function area(data) {
     var i,
         j,
diff --git a/src/line.js b/src/line.js
index ba3ae15..1ad92b2 100644
--- a/src/line.js
+++ b/src/line.js
@@ -4,14 +4,15 @@ import constant from "./constant.js";
 import curveLinear from "./curve/linear.js";
 import {x as pointX, y as pointY} from "./point.js";
 
-export default function() {
-  var x = pointX,
-      y = pointY,
-      defined = constant(true),
+export default function(x, y) {
+  var defined = constant(true),
       context = null,
       curve = curveLinear,
       output = null;
 
+  x = typeof x === "function" ? x : (x === undefined) ? pointX : constant(x);
+  y = typeof y === "function" ? y : (y === undefined) ? pointY : constant(y);
+
   function line(data) {
     var i,
         n = (data = array(data)).length,
diff --git a/test/area-test.js b/test/area-test.js
index 8d4bf75..6cdac04 100644
--- a/test/area-test.js
+++ b/test/area-test.js
@@ -16,6 +16,17 @@ tape("area() returns a default area shape", function(test) {
   test.end();
 });
 
+tape("area(x, y0, y1) sets x0, y0 and y1", function(test) {
+  var x = function() {}, y = function() {};
+  test.equal(shape.area(x).x0(), x);
+  test.equal(shape.area(x, y).y0(), y);
+  test.equal(shape.area(x, 0, y).y1(), y);
+  test.equal(shape.area(3, 2, 1).x0()("aa"), 3);
+  test.equal(shape.area(3, 2, 1).y0()("aa"), 2);
+  test.equal(shape.area(3, 2, 1).y1()("aa"), 1);
+  test.end();
+});
+
 tape("area.x(f)(data) passes d, i and data to the specified function f", function(test) {
   var data = ["a", "b"], actual = [];
   shape.area().x(function() { actual.push([].slice.call(arguments)); })(data);
diff --git a/test/line-test.js b/test/line-test.js
index 3505d20..c6d0865 100644
--- a/test/line-test.js
+++ b/test/line-test.js
@@ -14,6 +14,15 @@ tape("line() returns a default line shape", function(test) {
   test.end();
 });
 
+tape.only("line(x, y) sets x and y", function(test) {
+  var x = function() {}, y = function() {};
+  test.equal(shape.line(x).x(), x);
+  test.equal(shape.line(x, y).y(), y);
+  test.equal(shape.line(3, 2).x()("aa"), 3);
+  test.equal(shape.line(3, 2).y()("aa"), 2);
+  test.end();
+});
+
 tape("line.x(f)(data) passes d, i and data to the specified function f", function(test) {
   var data = ["a", "b"], actual = [];
   shape.line().x(function() { actual.push([].slice.call(arguments)); })(data);

From 4501d8728783658977ab3144ac20fe20d8363a77 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Rivi=C3=A8re?= <fil@rezo.net>
Date: Fri, 17 Jul 2020 18:16:51 +0200
Subject: [PATCH 11/16] document shorthand notation and ES6

---
 README.md | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 37e044d..5268a07 100644
--- a/README.md
+++ b/README.md
@@ -495,8 +495,8 @@ var data = [
 ];
 
 var area = d3.area()
-    .x(function(d) { return x(d.date); })
-    .y1(function(d) { return y(d.value); })
+    .x(d => x(d.date))
+    .y1(d => y(d.value))
     .y0(y(0));
 ```
 
@@ -637,9 +637,7 @@ While [lines](#lines) are defined as a sequence of two-dimensional [*x*, *y*] po
 Curves are typically not constructed or used directly, instead being passed to [*line*.curve](#line_curve) and [*area*.curve](#area_curve). For example:
 
 ```js
-var line = d3.line()
-    .x(function(d) { return x(d.date); })
-    .y(function(d) { return y(d.value); })
+var line = d3.line(d => d.date, d => d.value)
     .curve(d3.curveCatmullRom.alpha(0.5));
 ```
 

From d46aac54ae73e7ec3e562ca29c623b646ee42c4c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Rivi=C3=A8re?= <fil@rezo.net>
Date: Mon, 20 Jul 2020 11:14:15 +0200
Subject: [PATCH 12/16] shorthand notation symbol(type, size)

closes #155
---
 README.md           | 4 ++--
 src/symbol.js       | 8 ++++----
 test/symbol-test.js | 8 ++++++++
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 4b54341..8a849ec 100644
--- a/README.md
+++ b/README.md
@@ -904,9 +904,9 @@ Equivalent to [*link*.y](#link_y), except the accessor returns the radius: the d
 
 Symbols provide a categorical shape encoding as is commonly used in scatterplots. Symbols are always centered at ⟨0,0⟩; use a transform (see: [SVG](http://www.w3.org/TR/SVG/coords.html#TransformAttribute), [Canvas](http://www.w3.org/TR/2dcontext/#transformations)) to move the symbol to a different position.
 
-<a name="symbol" href="#symbol">#</a> d3.<b>symbol</b>() · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js)
+<a name="symbol" href="#symbol">#</a> d3.<b>symbol</b>([<i>type</i>][, <i>size</i>]) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js)
 
-Constructs a new symbol generator with the default settings.
+Constructs a new symbol generator of the specified [type](#symbol_type) and [size](#symbol_size). If not specified, *type* defaults to a circle, and *size* defaults to 64.
 
 <a name="_symbol" href="#_symbol">#</a> <i>symbol</i>(<i>arguments</i>…) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js)
 
diff --git a/src/symbol.js b/src/symbol.js
index 74530de..749b492 100644
--- a/src/symbol.js
+++ b/src/symbol.js
@@ -18,10 +18,10 @@ export var symbols = [
   wye
 ];
 
-export default function() {
-  var type = constant(circle),
-      size = constant(64),
-      context = null;
+export default function(type, size) {
+  var context = null;
+  type = typeof type === "function" ? type : constant(type || circle);
+  size = typeof size === "function" ? size : constant(size === undefined ? 64 : +size);
 
   function symbol() {
     var buffer;
diff --git a/test/symbol-test.js b/test/symbol-test.js
index 38dd91f..2a93fd7 100644
--- a/test/symbol-test.js
+++ b/test/symbol-test.js
@@ -140,3 +140,11 @@ tape("symbol.type(symbolWye) generates the expected path", function(test) {
   test.pathEqual(s(10), "M0.853360,0.492688L0.853360,2.199408L-0.853360,2.199408L-0.853360,0.492688L-2.331423,-0.360672L-1.478063,-1.838735L0,-0.985375L1.478063,-1.838735L2.331423,-0.360672Z");
   test.end();
 });
+
+tape("symbol(type, size) is equivalent to symbol().type(type).size(size)", function(test) {
+  var s0 = shape.symbol().type(shape.symbolCross).size(16),
+      s1 = shape.symbol(shape.symbolCross, 16);
+  test.equal(s0(), s1()); 
+  test.end();
+});
+

From d12c4f75b8af11c8ba1afae9c8ae685dfd3beb3a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Rivi=C3=A8re?= <fil@rezo.net>
Date: Mon, 27 Jul 2020 11:55:26 +0200
Subject: [PATCH 13/16] yarn.lock

---
 yarn.lock | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/yarn.lock b/yarn.lock
index d94b2de..82bc1d7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -169,15 +169,15 @@ cross-spawn@^6.0.5:
     shebang-command "^1.2.0"
     which "^1.2.9"
 
-d3-path@1:
-  version "1.0.9"
-  resolved "https://registry.yarnpkg.com/d3-path/-/d3-path-1.0.9.tgz#48c050bb1fe8c262493a8caf5524e3e9591701cf"
-  integrity sha512-VLaYcn81dtHVTjEHd8B+pbe9yHWpXKZUC87PzoFmsFrJqgFwDe/qxfp5MlfsfM1V5E/iVt0MmEbWQ7FVIXh/bg==
-
-d3-polygon@1:
-  version "1.0.6"
-  resolved "https://registry.yarnpkg.com/d3-polygon/-/d3-polygon-1.0.6.tgz#0bf8cb8180a6dc107f518ddf7975e12abbfbd38e"
-  integrity sha512-k+RF7WvI08PC8reEoXa/w2nSg5AUMTi+peBD9cmFc+0ixHfbs4QmxxkarVal1IkVkgxVuk9JSHhJURHiyHKAuQ==
+d3-path@>=2.0.0-rc.1:
+  version "2.0.0-rc.1"
+  resolved "https://registry.yarnpkg.com/d3-path/-/d3-path-2.0.0-rc.1.tgz#367192c0a1a83de31703b64726d772dba56d1cd5"
+  integrity sha512-sT5X1hMlP3s59ZZyY/qlAvIkZCpNcynrHaVc9cqMARs5w++4IjI1RwcPUt5zpkfflGvFN/tOPq+smk0Eljsyjw==
+
+d3-polygon@>=2.0.0-rc.1:
+  version "2.0.0-rc.1"
+  resolved "https://registry.yarnpkg.com/d3-polygon/-/d3-polygon-2.0.0-rc.1.tgz#2807d6e4c17714b528d7832c7854330ad50b0e68"
+  integrity sha512-5KLWKOU5NTPBMqDeYsXm9LUYkYDv7WMPgIhlW/hi5oSK6k0CDIimW6cBme12ruv1MNk60nZngdAbCRlGg/61FA==
 
 debug@^4.0.1:
   version "4.1.1"

From 3683fb892fd6fba0b63150053a0becd25ac8fe97 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Rivi=C3=A8re?= <fil@rezo.net>
Date: Mon, 27 Jul 2020 11:56:52 +0200
Subject: [PATCH 14/16] v2.0.0-rc.1

---
 package.json | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index abd321f..7af9ce8 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,9 @@
 {
   "name": "d3-shape",
-  "version": "1.3.7",
+  "version": "2.0.0-rc.1",
+  "publishConfig": {
+    "tag": "next"
+  },
   "description": "Graphical primitives for visualization, such as lines and areas.",
   "keywords": [
     "d3",
@@ -35,11 +38,11 @@
     "postpublish": "git push && git push --tags && cd ../d3.github.com && git pull && cp ../${npm_package_name}/dist/${npm_package_name}.js ${npm_package_name}.v${npm_package_version%%.*}.js && cp ../${npm_package_name}/dist/${npm_package_name}.min.js ${npm_package_name}.v${npm_package_version%%.*}.min.js && git add ${npm_package_name}.v${npm_package_version%%.*}.js ${npm_package_name}.v${npm_package_version%%.*}.min.js && git commit -m \"${npm_package_name} ${npm_package_version}\" && git push && cd - && zip -j dist/${npm_package_name}.zip -- LICENSE README.md dist/${npm_package_name}.js dist/${npm_package_name}.min.js"
   },
   "dependencies": {
-    "d3-path": "1"
+    "d3-path": ">=2.0.0-rc.1"
   },
   "sideEffects": false,
   "devDependencies": {
-    "d3-polygon": "1",
+    "d3-polygon": ">=2.0.0-rc.1",
     "eslint": "6",
     "rollup": "1",
     "rollup-plugin-terser": "5",

From 696ae24456522ec7a30246fb2b7a0605fab5d6b9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Rivi=C3=A8re?= <fil@rezo.net>
Date: Wed, 19 Aug 2020 18:36:39 +0200
Subject: [PATCH 15/16] reactivate tests

---
 test/line-test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/line-test.js b/test/line-test.js
index c6d0865..a26bc24 100644
--- a/test/line-test.js
+++ b/test/line-test.js
@@ -14,7 +14,7 @@ tape("line() returns a default line shape", function(test) {
   test.end();
 });
 
-tape.only("line(x, y) sets x and y", function(test) {
+tape("line(x, y) sets x and y", function(test) {
   var x = function() {}, y = function() {};
   test.equal(shape.line(x).x(), x);
   test.equal(shape.line(x, y).y(), y);

From b490be679379ae76838606b7fcb06ce2cbf8bfef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philippe=20Rivi=C3=A8re?= <fil@rezo.net>
Date: Wed, 19 Aug 2020 18:36:50 +0200
Subject: [PATCH 16/16] documentation links

---
 README.md | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/README.md b/README.md
index 898a08e..3f71958 100644
--- a/README.md
+++ b/README.md
@@ -902,15 +902,15 @@ Equivalent to [*link*.y](#link_y), except the accessor returns the radius: the d
 
 Symbols provide a categorical shape encoding as is commonly used in scatterplots. Symbols are always centered at ⟨0,0⟩; use a transform (see: [SVG](http://www.w3.org/TR/SVG/coords.html#TransformAttribute), [Canvas](http://www.w3.org/TR/2dcontext/#transformations)) to move the symbol to a different position.
 
-<a name="symbol" href="#symbol">#</a> d3.<b>symbol</b>([<i>type</i>][, <i>size</i>]) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js)
+<a name="symbol" href="#symbol">#</a> d3.<b>symbol</b>([<i>type</i>][, <i>size</i>]) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 Constructs a new symbol generator of the specified [type](#symbol_type) and [size](#symbol_size). If not specified, *type* defaults to a circle, and *size* defaults to 64.
 
-<a name="_symbol" href="#_symbol">#</a> <i>symbol</i>(<i>arguments</i>…) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js)
+<a name="_symbol" href="#_symbol">#</a> <i>symbol</i>(<i>arguments</i>…) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 Generates a symbol for the given *arguments*. The *arguments* are arbitrary; they are simply propagated to the symbol generator’s accessor functions along with the `this` object. For example, with the default settings, no arguments are needed to produce a circle with area 64 square pixels. If the symbol generator has a [context](#symbol_context), then the symbol is rendered to this context as a sequence of [path method](http://www.w3.org/TR/2dcontext/#canvaspathmethods) calls and this function returns void. Otherwise, a [path data](http://www.w3.org/TR/SVG/paths.html#PathData) string is returned.
 
-<a name="symbol_type" href="#symbol_type">#</a> <i>symbol</i>.<b>type</b>([<i>type</i>]) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js)
+<a name="symbol_type" href="#symbol_type">#</a> <i>symbol</i>.<b>type</b>([<i>type</i>]) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 If *type* is specified, sets the symbol type to the specified function or symbol type and returns this symbol generator. If *type* is a function, the symbol generator’s arguments and *this* are passed through. (See [*selection*.attr](https://github.com/d3/d3-selection/blob/master/README.md#selection_attr) if you are using d3-selection.) If *type* is not specified, returns the current symbol type accessor, which defaults to:
 
@@ -922,7 +922,7 @@ function type() {
 
 See [symbols](#symbols) for the set of built-in symbol types. To implement a custom symbol type, pass an object that implements [*symbolType*.draw](#symbolType_draw).
 
-<a name="symbol_size" href="#symbol_size">#</a> <i>symbol</i>.<b>size</b>([<i>size</i>]) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js)
+<a name="symbol_size" href="#symbol_size">#</a> <i>symbol</i>.<b>size</b>([<i>size</i>]) · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 If *size* is specified, sets the size to the specified function or number and returns this symbol generator. If *size* is a function, the symbol generator’s arguments and *this* are passed through. (See [*selection*.attr](https://github.com/d3/d3-selection/blob/master/README.md#selection_attr) if you are using d3-selection.) If *size* is not specified, returns the current size accessor, which defaults to:
 
@@ -938,39 +938,39 @@ Specifying the size as a function is useful for constructing a scatterplot with
 
 If *context* is specified, sets the context and returns this symbol generator. If *context* is not specified, returns the current context, which defaults to null. If the context is not null, then the [generated symbol](#_symbol) is rendered to this context as a sequence of [path method](http://www.w3.org/TR/2dcontext/#canvaspathmethods) calls. Otherwise, a [path data](http://www.w3.org/TR/SVG/paths.html#PathData) string representing the generated symbol is returned.
 
-<a name="symbols" href="#symbols">#</a> d3.<b>symbols</b>
+<a name="symbols" href="#symbols">#</a> d3.<b>symbols</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 An array containing the set of all built-in symbol types: [circle](#symbolCircle), [cross](#symbolCross), [diamond](#symbolDiamond), [square](#symbolSquare), [star](#symbolStar), [triangle](#symbolTriangle), and [wye](#symbolWye). Useful for constructing the range of an [ordinal scale](https://github.com/d3/d3-scale#ordinal-scales) should you wish to use a shape encoding for categorical data.
 
-<a name="symbolCircle" href="#symbolCircle">#</a> d3.<b>symbolCircle</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/circle.js)
+<a name="symbolCircle" href="#symbolCircle">#</a> d3.<b>symbolCircle</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/circle.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 The circle symbol type.
 
-<a name="symbolCross" href="#symbolCross">#</a> d3.<b>symbolCross</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/cross.js)
+<a name="symbolCross" href="#symbolCross">#</a> d3.<b>symbolCross</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/cross.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 The Greek cross symbol type, with arms of equal length.
 
-<a name="symbolDiamond" href="#symbolDiamond">#</a> d3.<b>symbolDiamond</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/diamond.js)
+<a name="symbolDiamond" href="#symbolDiamond">#</a> d3.<b>symbolDiamond</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/diamond.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 The rhombus symbol type.
 
-<a name="symbolSquare" href="#symbolSquare">#</a> d3.<b>symbolSquare</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/square.js)
+<a name="symbolSquare" href="#symbolSquare">#</a> d3.<b>symbolSquare</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/square.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 The square symbol type.
 
-<a name="symbolStar" href="#symbolStar">#</a> d3.<b>symbolStar</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/star.js)
+<a name="symbolStar" href="#symbolStar">#</a> d3.<b>symbolStar</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/star.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 The pentagonal star (pentagram) symbol type.
 
-<a name="symbolTriangle" href="#symbolTriangle">#</a> d3.<b>symbolTriangle</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/triangle.js)
+<a name="symbolTriangle" href="#symbolTriangle">#</a> d3.<b>symbolTriangle</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/triangle.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 The up-pointing triangle symbol type.
 
-<a name="symbolWye" href="#symbolWye">#</a> d3.<b>symbolWye</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/wye.js)
+<a name="symbolWye" href="#symbolWye">#</a> d3.<b>symbolWye</b> · [Source](https://github.com/d3/d3-shape/blob/master/src/symbol/wye.js), [Examples](https://observablehq.com/@d3/fitted-symbols)
 
 The Y-shape symbol type.
 
-<a name="pointRadial" href="#pointRadial">#</a> d3.<b>pointRadial</b>(<i>angle</i>, <i>radius</i>) · [Source](https://github.com/d3/d3-shape/blob/master/src/pointRadial.js)
+<a name="pointRadial" href="#pointRadial">#</a> d3.<b>pointRadial</b>(<i>angle</i>, <i>radius</i>) · [Source](https://github.com/d3/d3-shape/blob/master/src/pointRadial.js), [Examples](https://observablehq.com/@d3/radial-area-chart)
 
 Returns the point [<i>x</i>, <i>y</i>] for the given *angle* in radians, with 0 at -*y* (12 o’clock) and positive angles proceeding clockwise, and the given *radius*.