Accept iterables.

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)
 

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;

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();
+});
+