symbol edits

src/marks/dot.d.ts

@@ -1,14 +1,14 @@
 import type {ChannelValue, ChannelValueIntervalSpec, ChannelValueSpec} from "../channel.js";
 import type {Interval} from "../interval.js";
 import type {Data, FrameAnchor, MarkOptions, RenderableMark} from "../mark.js";
-import type {SymbolImplementation, SymbolName} from "../symbol.js";
+import type {SymbolType} from "../symbol.js";
 
 export interface DotOptions extends MarkOptions {
   x?: ChannelValueSpec;
   y?: ChannelValueSpec;
   r?: ChannelValueSpec | number;
   rotate?: ChannelValue | number;
-  symbol?: ChannelValueSpec | SymbolName | SymbolImplementation;
+  symbol?: ChannelValueSpec | SymbolType;
   frameAnchor?: FrameAnchor;
 }
 

src/marks/vector.d.ts

@@ -1,7 +1,12 @@
 import type {ChannelValue, ChannelValueSpec} from "../channel.js";
 import type {Data, FrameAnchor, MarkOptions, RenderableMark} from "../mark.js";
 
-/** The built-in vector shape implementations. */
+/**
+ * The built-in vector shape implementations; one of:
+ *
+ * - *arrow* - a straight line with an open arrowhead at the end (↑)
+ * - *spike* - an isosceles triangle with a flat base (▲)
+ */
 export type VectorShapeName = "arrow" | "spike";
 
 /** A vector shape implementation. */
@@ -10,7 +15,7 @@ export interface VectorShapeImplementation {
   draw(context: CanvasPath, length: number, radius: number): void;
 }
 
-/** How to draw a vector. */
+/** How to draw a vector: either a named shape or a custom implementation. */
 export type VectorShape = VectorShapeName | VectorShapeImplementation;
 
 /** Options for the vector mark. */

src/symbol.d.ts

@@ -1,5 +1,31 @@
-import type {SymbolType} from "d3";
+import type {SymbolType as SymbolImplementation} from "d3";
+export type {SymbolType as SymbolImplementation} from "d3";
 
+/**
+ * The built-in symbol implementations. For fill, one of:
+ *
+ * - *circle* - a circle
+ * - *cross* - a Greek cross with arms of equal length
+ * - *diamond* - a rhombus
+ * - *square* - a square
+ * - *star* - a pentagonal star (pentagram)
+ * - *triangle* - an up-pointing triangle
+ * - *wye* - a Y with arms of equal length
+ *
+ * For stroke (based on [Heman Robinson’s research][1]), one of:
+ *
+ * - *circle* - a circle
+ * - *plus* - a plus sign
+ * - *times* - an X with arms of equal length
+ * - *triangle2* - an (alternate) up-pointing triangle
+ * - *asterisk* - an asterisk
+ * - *square2* - a (alternate) square
+ * - *diamond2* - a rotated square
+ *
+ * The *hexagon* symbol is also supported.
+ *
+ * [1]: https://www.tandfonline.com/doi/abs/10.1080/10618600.2019.1637746
+ */
 export type SymbolName =
   | "asterisk"
   | "circle"
@@ -16,4 +42,5 @@ export type SymbolName =
   | "triangle2"
   | "wye";
 
-export type SymbolImplementation = SymbolType;
+/** How to draw a symbol: either a named symbol or a custom implementation. */
+export type SymbolType = SymbolName | SymbolImplementation;