stack shorthand

Author: mbostock

src/transforms/stack.js

@@ -3,34 +3,46 @@ import {ascendingDefined} from "../defined.js";
 import {field, lazyChannel, maybeLazyChannel, maybeZ, mid, range, valueof, identity, maybeZero} from "../mark.js";
 import {basic} from "./basic.js";
 
-export function stackX({y1, y = y1, x, ...options} = {}) {
-  const [transform, Y, x1, x2] = stack(y, x, "x", options);
-  return {y1, y: Y, x1, x2, x: mid(x1, x2), ...transform};
+export function stackX(stackOptions = {}, options = {}) {
+  if (arguments.length === 1) options = mergeOptions(stackOptions);
+  const {y1, y = y1, x, ...rest} = options; // note: consumes x!
+  const [transform, Y, x1, x2] = stack(y, x, "x", stackOptions, rest);
+  return {...transform, y1, y: Y, x1, x2, x: mid(x1, x2)};
 }
 
-export function stackX1({y1, y = y1, x, ...options} = {}) {
-  const [transform, Y, X] = stack(y, x, "x", options);
-  return {y1, y: Y, x: X, ...transform};
+export function stackX1(stackOptions = {}, options = {}) {
+  if (arguments.length === 1) options = mergeOptions(stackOptions);
+  const {y1, y = y1, x} = options;
+  const [transform, Y, X] = stack(y, x, "x", stackOptions, options);
+  return {...transform, y1, y: Y, x: X};
 }
 
-export function stackX2({y1, y = y1, x, ...options} = {}) {
-  const [transform, Y,, X] = stack(y, x, "x", options);
-  return {y1, y: Y, x: X, ...transform};
+export function stackX2(stackOptions = {}, options = {}) {
+  if (arguments.length === 1) options = mergeOptions(stackOptions);
+  const {y1, y = y1, x} = options;
+  const [transform, Y,, X] = stack(y, x, "x", stackOptions, options);
+  return {...transform, y1, y: Y, x: X};
 }
 
-export function stackY({x1, x = x1, y, ...options} = {}) {
-  const [transform, X, y1, y2] = stack(x, y, "y", options);
-  return {x1, x: X, y1, y2, y: mid(y1, y2), ...transform};
+export function stackY(stackOptions = {}, options = {}) {
+  if (arguments.length === 1) options = mergeOptions(stackOptions);
+  const {x1, x = x1, y, ...rest} = options; // note: consumes y!
+  const [transform, X, y1, y2] = stack(x, y, "y", stackOptions, rest);
+  return {...transform, x1, x: X, y1, y2, y: mid(y1, y2)};
 }
 
-export function stackY1({x1, x = x1, y, ...options} = {}) {
-  const [transform, X, Y] = stack(x, y, "y", options);
-  return {x1, x: X, y: Y, ...transform};
+export function stackY1(stackOptions = {}, options = {}) {
+  if (arguments.length === 1) options = mergeOptions(stackOptions);
+  const {x1, x = x1, y} = options;
+  const [transform, X, Y] = stack(x, y, "y", stackOptions, options);
+  return {...transform, x1, x: X, y: Y};
 }
 
-export function stackY2({x1, x = x1, y, ...options} = {}) {
-  const [transform, X,, Y] = stack(x, y, "y", options);
-  return {x1, x: X, y: Y, ...transform};
+export function stackY2(stackOptions = {}, options = {}) {
+  if (arguments.length === 1) options = mergeOptions(stackOptions);
+  const {x1, x = x1, y} = options;
+  const [transform, X,, Y] = stack(x, y, "y", stackOptions, options);
+  return {...transform, x1, x: X, y: Y};
 }
 
 export function maybeStackX({x, x1, x2, ...options} = {}) {
@@ -51,7 +63,15 @@ export function maybeStackY({y, y1, y2, ...options} = {}) {
   return {...options, y1, y2};
 }
 
-function stack(x, y = () => 1, ky, {offset, order, reverse, ...options} = {}) {
+// The reverse option is ambiguous: it is both a stack option and a basic
+// transform. If only one options object is specified, we interpret it as a
+// stack option, and therefore must remove it from the propagated options.
+function mergeOptions(options) {
+  const {reverse} = options;
+  return reverse ? {...options, reverse: false} : options;
+}
+
+function stack(x, y = () => 1, ky, {offset, order, reverse}, options) {
   const z = maybeZ(options);
   const [X, setX] = maybeLazyChannel(x);
   const [Y1, setY1] = lazyChannel(y);