more type specificity

Author: mbostock

src/interval.d.ts

@@ -82,10 +82,10 @@ export interface NiceIntervalImplementation<T> extends RangeIntervalImplementati
 type LiteralInterval<T> = T extends Date ? TimeIntervalName : T extends number ? number : never;
 
 /** How to partition a continuous range into discrete intervals. */
-export type Interval<T = any> = LiteralInterval<T> | IntervalImplementation<T>;
+export type Interval<T = number | Date> = LiteralInterval<T> | IntervalImplementation<T>;
 
 /** An interval that supports the range method, say for thresholds or ticks. */
-export type RangeInterval<T = any> = LiteralInterval<T> | RangeIntervalImplementation<T>;
+export type RangeInterval<T = number | Date> = LiteralInterval<T> | RangeIntervalImplementation<T>;
 
 /** An interval that can be used to nice a scale domain. */
-export type NiceInterval<T = any> = LiteralInterval<T> | NiceIntervalImplementation<T>;
+export type NiceInterval<T = number | Date> = LiteralInterval<T> | NiceIntervalImplementation<T>;

src/reducer.d.ts

@@ -25,11 +25,12 @@ export type ReducerName =
   | "mode"
   | ReducerPercentile;
 
-export type ReducerFunction = (values: any[]) => any;
+export type ReducerFunction<S = any, T = S> = (values: S[]) => T;
 
-// TODO scope, label
-export interface ReducerImplementation {
-  reduceIndex(index: number[], values: any[]): any;
+export interface ReducerImplementation<S = any, T = S> {
+  reduceIndex(index: number[], values: S[]): T;
+  // TODO scope
+  // TODO label
 }
 
 /** How to reduce aggregated values. */

src/transforms/bin.d.ts

@@ -7,13 +7,13 @@ import type {Transformed} from "./basic.js";
 export type ThresholdsName = "freedman-diaconis" | "scott" | "sturges" | "auto";
 
 /** How to subdivide a continuous domain into discrete bins (based on data). */
-export type ThresholdsFunction = (values: any[], min: any, max: any) => any[] | RangeInterval | number;
+export type ThresholdsFunction<T = number | Date> = (values: T[], min: T, max: T) => T[] | RangeInterval<T> | number;
 
 /** How to subdivide a continuous domain into discrete bins. */
-export type Thresholds = ThresholdsName | ThresholdsFunction | RangeInterval | any[];
+export type Thresholds<T = number | Date> = ThresholdsName | ThresholdsFunction<T> | RangeInterval<T> | T[] | number;
 
 /** Options for the bin transform. */
-export interface BinOptions {
+export interface BinOptions<T = number | Date> {
   /**
    * If true or a positive number, produce a cumulative distribution; if a
    * negative number, produce a [complementary cumulative](https://en.wikipedia.org/wiki/Cumulative_distribution_function#Complementary_cumulative_distribution_function_.28tail_distribution.29)
@@ -30,7 +30,7 @@ export interface BinOptions {
    * domain is used, the start and end of the domain will be extended to align
    * with the interval.
    */
-  domain?: ((values: any[]) => [min: any, max: any]) | [min: any, max: any];
+  domain?: ((values: T[]) => [min: T, max: T]) | [min: T, max: T];
 
   /**
    * How to subdivide the domain into bins. May be one of:
@@ -44,7 +44,7 @@ export interface BinOptions {
    * * an interval; see **interval**
    * * a function that returns an array, count, or interval
    */
-  thresholds?: Thresholds;
+  thresholds?: Thresholds<T>;
 
   /**
    * How to subdivide the domain into bins; an alternative to **thresholds**.
@@ -53,7 +53,7 @@ export interface BinOptions {
    * number *n*, threshold values are consecutive multiples of *n* that span the
    * domain.
    */
-  interval?: RangeInterval;
+  interval?: RangeInterval<T>;
 }
 
 /** How to reduce binned values. */