Generic sort and filter transforms. (#205)

* {filter, transform} closes #138 supersedes #194 * generic sort, filter * tolerate null Co-authored-by: Philippe Rivière <[email protected]>
observablehq · Mar 9, 2021 · 38c66a6 · 38c66a6
1 parent 54e79fc
commit 38c66a6
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diff --git a/src/mark.js b/src/mark.js
@@ -1,17 +1,15 @@
-import {sort} from "d3-array";
 import {color} from "d3-color";
-import {nonempty} from "./defined.js";
+import {ascendingDefined, nonempty} from "./defined.js";
 
 // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray
 const TypedArray = Object.getPrototypeOf(Uint8Array);
 const objectToString = Object.prototype.toString;
 
 export class Mark {
-  constructor(data, channels = [], transform) {
-    if (transform == null) transform = undefined;
+  constructor(data, channels = [], options = {}) {
     const names = new Set();
     this.data = arrayify(data);
-    this.transform = transform;
+    this.transform = maybeTransform(options);
     this.channels = channels.filter(channel => {
       const {name, value, optional} = channel;
       if (value == null) {
@@ -133,15 +131,6 @@ export function maybeZero(x, x1, x2, x3 = identity) {
   return [x1, x2];
 }
 
-// If a sort order is specified, returns a corresponding transform.
-// TODO Allow the sort order to be specified as an array.
-export function maybeSort(order) {
-  if (order !== undefined) {
-    if (typeof order !== "function") order = field(order);
-    return data => sort(data, order);
-  }
-}
-
 // A helper for extracting the z channel, if it is variable. Used by transforms
 // that require series, such as moving average and normalize.
 export function maybeZ({z, fill, stroke} = {}) {
@@ -199,13 +188,12 @@ export function maybeLazyChannel(source) {
 
 // If both t1 and t2 are defined, returns a composite transform that first
 // applies t1 and then applies t2.
-export function maybeTransform({transform: t1} = {}, t2) {
-  if (t1 === undefined) return t2;
-  if (t2 === undefined) return t1;
-  return (data, index) => {
-    ({data, index} = t1(data, index));
-    return t2(arrayify(data), index);
-  };
+export function maybeTransform({filter: f1, sort: s1, transform: t1} = {}, t2) {
+  if (t1 === undefined) {
+    if (f1 != null) t1 = filter(f1);
+    if (s1 != null) t1 = compose(t1, sort(s1));
+  }
+  return compose(t1, t2);
 }
 
 // Assuming that both x1 and x2 and lazy channels (per above), this derives a
@@ -226,3 +214,38 @@ export function mid(x1, x2) {
 export function maybeValue(value) {
   return typeof value === "undefined" || (value && value.toString === objectToString) ? value : {value};
 }
+
+function compose(t1, t2) {
+  if (t1 == null) return t2 === null ? undefined : t2;
+  if (t2 == null) return t1 === null ? undefined : t1;
+  return (data, index) => {
+    ({data, index} = t1(data, index));
+    return t2(arrayify(data), index);
+  };
+}
+
+function sort(value) {
+  return (typeof value === "function" && value.length !== 1 ? sortCompare : sortValue)(value);
+}
+
+function sortCompare(compare) {
+  return (data, index) => {
+    const compareData = (i, j) => compare(data[i], data[j]);
+    return {data, index: index.map(I => I.slice().sort(compareData))};
+  };
+}
+
+function sortValue(value) {
+  return (data, index) => {
+    const V = valueof(data, value);
+    const compareValue = (i, j) => ascendingDefined(V[i], V[j]);
+    return {data, index: index.map(I => I.slice().sort(compareValue))};
+  };
+}
+
+function filter(value) {
+  return (data, index) => {
+    const V = valueof(data, value);
+    return {data, index: index.map(I => I.filter(i => V[i]))};
+  };
+}
diff --git a/src/marks/area.js b/src/marks/area.js
@@ -3,7 +3,7 @@ import {create} from "d3-selection";
 import {area as shapeArea} from "d3-shape";
 import {Curve} from "../curve.js";
 import {defined} from "../defined.js";
-import {Mark, indexOf, maybeColor, maybeZero, maybeSort, first, second, titleGroup} from "../mark.js";
+import {Mark, indexOf, maybeColor, maybeZero, first, second, titleGroup} from "../mark.js";
 import {Style, applyDirectStyles, applyIndirectStyles, applyTransform} from "../style.js";
 
 export class Area extends Mark {
@@ -20,9 +20,7 @@ export class Area extends Mark {
       stroke,
       curve,
       tension,
-      sort,
-      transform = maybeSort(sort),
-      ...style
+      ...options
     } = {}
   ) {
     const [vfill, cfill] = maybeColor(fill, "currentColor");
@@ -41,14 +39,14 @@ export class Area extends Mark {
         {name: "fill", value: vfill, scale: "color", optional: true},
         {name: "stroke", value: vstroke, scale: "color", optional: true}
       ],
-      transform
+      options
     );
     this.curve = Curve(curve, tension);
     Style(this, {
       fill: cfill,
       stroke: cstroke,
       strokeMiterlimit: cstroke === "none" ? undefined : 1,
-      ...style
+      ...options
     });
   }
   render(I, {x, y, color}, {x1: X1, y1: Y1, x2: X2 = X1, y2: Y2 = Y1, z: Z, title: L, fill: F, stroke: S}) {

diff --git a/src/marks/bar.js b/src/marks/bar.js
@@ -20,8 +20,7 @@ export class AbstractBar extends Mark {
       insetLeft = inset,
       rx,
       ry,
-      transform,
-      ...style
+      ...options
     } = {}
   ) {
     const [vfill, cfill] = maybeColor(fill, "currentColor");
@@ -35,9 +34,9 @@ export class AbstractBar extends Mark {
         {name: "fill", value: vfill, scale: "color", optional: true},
         {name: "stroke", value: vstroke, scale: "color", optional: true}
       ],
-      transform
+      options
     );
-    Style(this, {fill: cfill, stroke: cstroke, ...style});
+    Style(this, {fill: cfill, stroke: cstroke, ...options});
     this.insetTop = number(insetTop);
     this.insetRight = number(insetRight);
     this.insetBottom = number(insetBottom);

diff --git a/src/marks/dot.js b/src/marks/dot.js
@@ -15,8 +15,7 @@ export class Dot extends Mark {
       title,
       fill,
       stroke,
-      transform,
-      ...style
+      ...options
     } = {}
   ) {
     const [vr, cr] = maybeNumber(r, 3);
@@ -33,14 +32,14 @@ export class Dot extends Mark {
         {name: "fill", value: vfill, scale: "color", optional: true},
         {name: "stroke", value: vstroke, scale: "color", optional: true}
       ],
-      transform
+      options
     );
     this.r = cr;
     Style(this, {
       fill: cfill,
       stroke: cstroke,
       strokeWidth: cstroke === "none" ? undefined : 1.5,
-      ...style
+      ...options
     });
   }
   render(

diff --git a/src/marks/line.js b/src/marks/line.js
@@ -3,7 +3,7 @@ import {create} from "d3-selection";
 import {line as shapeLine} from "d3-shape";
 import {Curve} from "../curve.js";
 import {defined} from "../defined.js";
-import {Mark, indexOf, identity, first, second, maybeColor, maybeSort, titleGroup} from "../mark.js";
+import {Mark, indexOf, identity, first, second, maybeColor, titleGroup} from "../mark.js";
 import {Style, applyDirectStyles, applyIndirectStyles, applyTransform} from "../style.js";
 
 export class Line extends Mark {
@@ -18,9 +18,7 @@ export class Line extends Mark {
       stroke,
       curve,
       tension,
-      sort,
-      transform = maybeSort(sort),
-      ...style
+      ...options
     } = {}
   ) {
     const [vfill, cfill] = maybeColor(fill, "none");
@@ -37,15 +35,15 @@ export class Line extends Mark {
         {name: "fill", value: vfill, scale: "color", optional: true},
         {name: "stroke", value: vstroke, scale: "color", optional: true}
       ],
-      transform
+      options
     );
     this.curve = Curve(curve, tension);
     Style(this, {
       fill: cfill,
       stroke: cstroke,
       strokeWidth: cstroke === "none" ? undefined : 1.5,
       strokeMiterlimit: cstroke === "none" ? undefined : 1,
-      ...style
+      ...options
     });
   }
   render(I, {x, y, color}, {x: X, y: Y, z: Z, title: L, fill: F, stroke: S}) {

diff --git a/src/marks/link.js b/src/marks/link.js
@@ -15,8 +15,7 @@ export class Link extends Mark {
       z,
       title,
       stroke,
-      transform,
-      ...style
+      ...options
     } = {}
   ) {
     const [vstroke, cstroke] = maybeColor(stroke, "currentColor");
@@ -31,9 +30,9 @@ export class Link extends Mark {
         {name: "title", value: title, optional: true},
         {name: "stroke", value: vstroke, scale: "color", optional: true}
       ],
-      transform
+      options
     );
-    Style(this, {stroke: cstroke, ...style});
+    Style(this, {stroke: cstroke, ...options});
   }
   render(
     I,

diff --git a/src/marks/rect.js b/src/marks/rect.js
@@ -23,8 +23,7 @@ export class Rect extends Mark {
       insetLeft = inset,
       rx,
       ry,
-      transform,
-      ...style
+      ...options
     } = {}
   ) {
     const [vfill, cfill] = maybeColor(fill, "currentColor");
@@ -41,9 +40,9 @@ export class Rect extends Mark {
         {name: "fill", value: vfill, scale: "color", optional: true},
         {name: "stroke", value: vstroke, scale: "color", optional: true}
       ],
-      transform
+      options
     );
-    Style(this, {fill: cfill, stroke: cstroke, ...style});
+    Style(this, {fill: cfill, stroke: cstroke, ...options});
     this.insetTop = number(insetTop);
     this.insetRight = number(insetRight);
     this.insetBottom = number(insetBottom);

diff --git a/src/marks/rule.js b/src/marks/rule.js
@@ -14,8 +14,7 @@ export class RuleX extends Mark {
       z,
       title,
       stroke,
-      transform,
-      ...style
+      ...options
     } = {}
   ) {
     const [vstroke, cstroke] = maybeColor(stroke, "currentColor");
@@ -29,9 +28,9 @@ export class RuleX extends Mark {
         {name: "title", value: title, optional: true},
         {name: "stroke", value: vstroke, scale: "color", optional: true}
       ],
-      transform
+      options
     );
-    Style(this, {stroke: cstroke, ...style});
+    Style(this, {stroke: cstroke, ...options});
   }
   render(
     I,

diff --git a/src/marks/text.js b/src/marks/text.js
@@ -14,7 +14,6 @@ export class Text extends Mark {
       text = indexOf,
       title,
       fill,
-      transform,
       textAnchor,
       fontFamily,
       fontSize,
@@ -23,7 +22,7 @@ export class Text extends Mark {
       fontWeight,
       dx,
       dy = "0.32em",
-      ...style
+      ...options
     } = {}
   ) {
     const [vfill, cfill] = maybeColor(fill, "currentColor");
@@ -37,9 +36,9 @@ export class Text extends Mark {
         {name: "title", value: title, optional: true},
         {name: "fill", value: vfill, scale: "color", optional: true}
       ],
-      transform
+      options
     );
-    Style(this, {fill: cfill, ...style});
+    Style(this, {fill: cfill, ...options});
     this.textAnchor = string(textAnchor);
     this.fontFamily = string(fontFamily);
     this.fontSize = string(fontSize);

diff --git a/src/marks/tick.js b/src/marks/tick.js
@@ -12,8 +12,7 @@ class AbstractTick extends Mark {
       z,
       title,
       stroke,
-      transform,
-      ...style
+      ...options
     } = {}
   ) {
     const [vstroke, cstroke] = maybeColor(stroke, "currentColor");
@@ -25,9 +24,9 @@ class AbstractTick extends Mark {
         {name: "title", value: title, optional: true},
         {name: "stroke", value: vstroke, scale: "color", optional: true}
       ],
-      transform
+      options
     );
-    Style(this, {stroke: cstroke, ...style});
+    Style(this, {stroke: cstroke, ...options});
   }
   render(I, scales, channels, dimensions) {
     const {color} = scales;