mark.channels is an object (#994)

* mark.channels is an object

* object all the channels

Author: mbostock

src/channel.js

@@ -15,23 +15,18 @@ export function Channel(data, {scale, type, value, filter, hint}) {
   };
 }
 
-export function channelObject(channelDescriptors, data) {
-  const channels = {};
-  for (const channel of channelDescriptors) {
-    channels[channel.name] = Channel(data, channel);
-  }
-  return channels;
+export function Channels(descriptors, data) {
+  return Object.fromEntries(Object.entries(descriptors).map(([name, channel]) => {
+    return [name, Channel(data, channel)];
+  }));
 }
 
 // TODO Use Float64Array for scales with numeric ranges, e.g. position?
 export function valueObject(channels, scales) {
-  const values = {};
-  for (const channelName in channels) {
-    const {scale: scaleName, value} = channels[channelName];
+  return Object.fromEntries(Object.entries(channels).map(([name, {scale: scaleName, value}]) => {
     const scale = scales[scaleName];
-    values[channelName] = scale === undefined ? value : map(value, scale);
-  }
-  return values;
+    return [name, scale === undefined ? value : map(value, scale)];
+  }));
 }
 
 // Note: mutates channel.domain! This is set to a function so that it is lazily

src/marks/area.js

@@ -21,13 +21,13 @@ export class Area extends Mark {
     const {x1, y1, x2, y2, z, curve, tension} = options;
     super(
       data,
-      [
-        {name: "x1", value: x1, scale: "x"},
-        {name: "y1", value: y1, scale: "y"},
-        {name: "x2", value: x2, scale: "x", optional: true},
-        {name: "y2", value: y2, scale: "y", optional: true},
-        {name: "z", value: maybeZ(options), optional: true}
-      ],
+      {
+        x1: {value: x1, scale: "x"},
+        y1: {value: y1, scale: "y"},
+        x2: {value: x2, scale: "x", optional: true},
+        y2: {value: y2, scale: "y", optional: true},
+        z: {value: maybeZ(options), optional: true}
+      },
       options,
       defaults
     );

src/marks/arrow.js

@@ -30,12 +30,12 @@ export class Arrow extends Mark {
     } = options;
     super(
       data,
-      [
-        {name: "x1", value: x1, scale: "x"},
-        {name: "y1", value: y1, scale: "y"},
-        {name: "x2", value: x2, scale: "x", optional: true},
-        {name: "y2", value: y2, scale: "y", optional: true}
-      ],
+      {
+        x1: {value: x1, scale: "x"},
+        y1: {value: y1, scale: "y"},
+        x2: {value: x2, scale: "x", optional: true},
+        y2: {value: y2, scale: "y", optional: true}
+      },
       options,
       defaults
     );

src/marks/bar.js

@@ -66,11 +66,11 @@ export class BarX extends AbstractBar {
     const {x1, x2, y} = options;
     super(
       data,
-      [
-        {name: "x1", value: x1, scale: "x"},
-        {name: "x2", value: x2, scale: "x"},
-        {name: "y", value: y, scale: "y", type: "band", optional: true}
-      ],
+      {
+        x1: {value: x1, scale: "x"},
+        x2: {value: x2, scale: "x"},
+        y: {value: y, scale: "y", type: "band", optional: true}
+      },
       options,
       defaults
     );
@@ -93,11 +93,11 @@ export class BarY extends AbstractBar {
     const {x, y1, y2} = options;
     super(
       data,
-      [
-        {name: "y1", value: y1, scale: "y"},
-        {name: "y2", value: y2, scale: "y"},
-        {name: "x", value: x, scale: "x", type: "band", optional: true}
-      ],
+      {
+        y1: {value: y1, scale: "y"},
+        y2: {value: y2, scale: "y"},
+        x: {value: x, scale: "x", type: "band", optional: true}
+      },
       options,
       defaults
     );

src/marks/cell.js

@@ -10,10 +10,10 @@ export class Cell extends AbstractBar {
   constructor(data, {x, y, ...options} = {}) {
     super(
       data,
-      [
-        {name: "x", value: x, scale: "x", type: "band", optional: true},
-        {name: "y", value: y, scale: "y", type: "band", optional: true}
-      ],
+      {
+        x: {value: x, scale: "x", type: "band", optional: true},
+        y: {value: y, scale: "y", type: "band", optional: true}
+      },
       options,
       defaults
     );

src/marks/delaunay.js

@@ -47,11 +47,11 @@ class DelaunayLink extends Mark {
     const {x, y, z, curve, tension} = options;
     super(
       data,
-      [
-        {name: "x", value: x, scale: "x", optional: true},
-        {name: "y", value: y, scale: "y", optional: true},
-        {name: "z", value: z, optional: true}
-      ],
+      {
+        x: {value: x, scale: "x", optional: true},
+        y: {value: y, scale: "y", optional: true},
+        z: {value: z, optional: true}
+      },
       options,
       delaunayLinkDefaults
     );
@@ -129,11 +129,11 @@ class AbstractDelaunayMark extends Mark {
     const {x, y} = options;
     super(
       data,
-      [
-        {name: "x", value: x, scale: "x", optional: true},
-        {name: "y", value: y, scale: "y", optional: true},
-        {name: "z", value: zof(options), optional: true}
-      ],
+      {
+        x: {value: x, scale: "x", optional: true},
+        y: {value: y, scale: "y", optional: true},
+        z: {value: zof(options), optional: true}
+      },
       options,
       defaults
     );
@@ -188,11 +188,11 @@ class Voronoi extends Mark {
     const {x, y, z} = options;
     super(
       data,
-      [
-        {name: "x", value: x, scale: "x", optional: true},
-        {name: "y", value: y, scale: "y", optional: true},
-        {name: "z", value: z, optional: true}
-      ],
+      {
+        x: {value: x, scale: "x", optional: true},
+        y: {value: y, scale: "y", optional: true},
+        z: {value: z, optional: true}
+      },
       options,
       voronoiDefaults
     );

src/marks/density.js

@@ -22,12 +22,12 @@ export class Density extends Mark {
     const strokeDensity = isDensity(stroke) && (stroke = "currentColor", true);
     super(
       data,
-      [
-        {name: "x", value: x, scale: "x", optional: true},
-        {name: "y", value: y, scale: "y", optional: true},
-        {name: "z", value: maybeZ({z, fill, stroke}), optional: true},
-        {name: "weight", value: weight, optional: true}
-      ],
+      {
+        x: {value: x, scale: "x", optional: true},
+        y: {value: y, scale: "y", optional: true},
+        z: {value: maybeZ({z, fill, stroke}), optional: true},
+        weight: {value: weight, optional: true}
+      },
       densityInitializer({...options, fill, stroke}, fillDensity, strokeDensity),
       defaults
     );

src/marks/dot.js

@@ -23,13 +23,13 @@ export class Dot extends Mark {
     const [vr, cr] = maybeNumberChannel(r, vsymbol == null ? 3 : 4.5);
     super(
       data,
-      [
-        {name: "x", value: x, scale: "x", optional: true},
-        {name: "y", value: y, scale: "y", optional: true},
-        {name: "r", value: vr, scale: "r", filter: positive, optional: true},
-        {name: "rotate", value: vrotate, optional: true},
-        {name: "symbol", value: vsymbol, scale: "symbol", optional: true}
-      ],
+      {
+        x: {value: x, scale: "x", optional: true},
+        y: {value: y, scale: "y", optional: true},
+        r: {value: vr, scale: "r", filter: positive, optional: true},
+        rotate: {value: vrotate, optional: true},
+        symbol: {value: vsymbol, scale: "symbol", optional: true}
+      },
       options.sort === undefined && options.reverse === undefined ? sort({channel: "r", order: "descending"}, options) : options,
       defaults
     );
@@ -42,10 +42,9 @@ export class Dot extends Mark {
     // appropriate default symbols based on whether the dots are filled or
     // stroked, and for the symbol legend to match the appearance of the dots.
     const {channels} = this;
-    const symbolChannel = channels.find(({scale}) => scale === "symbol");
+    const {symbol: symbolChannel} = channels;
     if (symbolChannel) {
-      const fillChannel = channels.find(({name}) => name === "fill");
-      const strokeChannel = channels.find(({name}) => name === "stroke");
+      const {fill: fillChannel, stroke: strokeChannel} = channels;
       symbolChannel.hint = {
         fill: fillChannel ? (fillChannel.value === symbolChannel.value ? "color" : "currentColor") : this.fill,
         stroke: strokeChannel ? (strokeChannel.value === symbolChannel.value ? "color" : "currentColor") : this.stroke

src/marks/image.js

@@ -42,13 +42,13 @@ export class Image extends Mark {
     const [vh, ch] = maybeNumberChannel(height, 16);
     super(
       data,
-      [
-        {name: "x", value: x, scale: "x", optional: true},
-        {name: "y", value: y, scale: "y", optional: true},
-        {name: "width", value: vw, filter: positive, optional: true},
-        {name: "height", value: vh, filter: positive, optional: true},
-        {name: "src", value: vs, optional: true}
-      ],
+      {
+        x: {value: x, scale: "x", optional: true},
+        y: {value: y, scale: "y", optional: true},
+        width: {value: vw, filter: positive, optional: true},
+        height: {value: vh, filter: positive, optional: true},
+        src: {value: vs, optional: true}
+      },
       options,
       defaults
     );

src/marks/line.js

@@ -22,11 +22,11 @@ export class Line extends Mark {
     const {x, y, z, curve, tension} = options;
     super(
       data,
-      [
-        {name: "x", value: x, scale: "x"},
-        {name: "y", value: y, scale: "y"},
-        {name: "z", value: maybeZ(options), optional: true}
-      ],
+      {
+        x: {value: x, scale: "x"},
+        y: {value: y, scale: "y"},
+        z: {value: maybeZ(options), optional: true}
+      },
       options,
       defaults
     );