@thi.ng/transducers - npm Package Compare versions

Comparing version 0.8.0 to 0.9.0

func/comp.js

@@ -6,2 +6,4 @@ "use strict";
     switch (fns.length) {
+        case 0:
+            throw new Error("no fn args given");
         case 1:
@@ -26,10 +28,5 @@ return a;
         case 10:
-            return (x) => a(b(c(d(e(f(g(h(i(j(x))))))))));
         default:
-            return (x) => {
-                for (let i = fns.length - 1; i >= 0; i--) {
-                    x = fns[i](x);
-                }
-                return x;
-            };
+            let ff = (x) => a(b(c(d(e(f(g(h(i(j(x))))))))));
+            return fns.length === 10 ? ff : comp(ff, ...fns.slice(10));
     }
@@ -36,0 +33,0 @@ }

func/juxt.d.ts

@@ -9,1 +9,2 @@ export declare type Fn<A, B> = (x: A) => B;
 export declare function juxt<T, A, B, C, D, E, F, G>(a: Fn<T, A>, b: Fn<T, B>, c: Fn<T, C>, d: Fn<T, D>, e: Fn<T, E>, f: Fn<T, F>, g: Fn<T, G>): Fn<T, [A, B, C, D, E, F, G]>;
+export declare function juxt<T, A, B, C, D, E, F, G, H>(a: Fn<T, A>, b: Fn<T, B>, c: Fn<T, C>, d: Fn<T, D>, e: Fn<T, E>, f: Fn<T, F>, g: Fn<T, G>, h: Fn<T, H>): Fn<T, [A, B, C, D, E, F, G, H]>;

func/juxt.js

 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
 function juxt(...fns) {
-    const [a, b, c, d] = fns;
+    const [a, b, c, d, e, f, g, h] = fns;
     switch (fns.length) {
@@ -14,5 +14,13 @@ case 1:
             return (x) => [a(x), b(x), c(x), d(x)];
+        case 5:
+            return (x) => [a(x), b(x), c(x), d(x), e(x)];
+        case 6:
+            return (x) => [a(x), b(x), c(x), d(x), e(x), f(x)];
+        case 7:
+            return (x) => [a(x), b(x), c(x), d(x), e(x), f(x), g(x)];
+        case 8:
+            return (x) => [a(x), b(x), c(x), d(x), e(x), f(x), g(x), h(x)];
         default:
             return function (x) {
-                let res = [];
+                let res = new Array(fns.length);
                 for (let i = fns.length - 1; i >= 0; i--) {
@@ -19,0 +27,0 @@ res[i] = fns[i](x);

index.d.ts

@@ -26,2 +26,3 @@ export * from "./api";
 export * from "./xform/benchmark";
+export * from "./xform/bits";
 export * from "./xform/cat";
@@ -38,2 +39,3 @@ export * from "./xform/dedupe";
 export * from "./xform/flatten";
+export * from "./xform/hex-dump";
 export * from "./xform/indexed";
@@ -49,2 +51,3 @@ export * from "./xform/inspect";
 export * from "./xform/moving-average";
+export * from "./xform/pad-last";
 export * from "./xform/partition-by";
@@ -70,2 +73,3 @@ export * from "./xform/partition-sort";
 export * from "./func/delay";
+export * from "./func/hex";
 export * from "./func/identity";
@@ -76,2 +80,4 @@ export * from "./func/juxt";
 export * from "./func/swizzler";
+export * from "./func/weighted-random";
+export * from "./iter/choices";
 export * from "./iter/constantly";
@@ -78,0 +84,0 @@ export * from "./iter/cycle";

index.js

@@ -31,2 +31,3 @@ "use strict";
 __export(require("./xform/benchmark"));
+__export(require("./xform/bits"));
 __export(require("./xform/cat"));
@@ -43,2 +44,3 @@ __export(require("./xform/dedupe"));
 __export(require("./xform/flatten"));
+__export(require("./xform/hex-dump"));
 __export(require("./xform/indexed"));
@@ -54,2 +56,3 @@ __export(require("./xform/inspect"));
 __export(require("./xform/moving-average"));
+__export(require("./xform/pad-last"));
 __export(require("./xform/partition-by"));
@@ -75,2 +78,3 @@ __export(require("./xform/partition-sort"));
 __export(require("./func/delay"));
+__export(require("./func/hex"));
 __export(require("./func/identity"));
@@ -81,2 +85,4 @@ __export(require("./func/juxt"));
 __export(require("./func/swizzler"));
+__export(require("./func/weighted-random"));
+__export(require("./iter/choices"));
 __export(require("./iter/constantly"));
@@ -83,0 +89,0 @@ __export(require("./iter/cycle"));

package.json

 {
     "name": "@thi.ng/transducers",
-    "version": "0.8.0",
+    "version": "0.9.0",
     "description": "Lightweight transducer implementations for ES6 / TypeScript",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

@@ -5,15 +5,33 @@ # @thi.ng/transducers
 
-Lightweight transducer implementations for ES6 / TypeScript (19KB minified, full lib).
+Lightweight transducer implementations for ES6 / TypeScript (21KB minified, full lib).
 
-Currently, the library provides altogether 65+ transducers, reducers and
-generators for composing data transformation pipelines.
+## TOC
 
-The overall concept and many of the functions offered here are directly
+- [Installation](#installation)
+- [Usage examples](#usage-examples)
+- [API](#api)
+  - [Types](#types)
+  - [Transformations](#transformations)
+  - [Transducers](#transducers)
+  - [Reducers](#reducers)
+  - [Generators & iterators](#generators--iterators)
+- [License](#license)
+
+## About
+
+Currently, the library provides altogether 70+ transducers, reducers and
+sequence generators for composing data transformation pipelines.
+
+The overall concept and many of the core functions offered here are directly
 inspired by the original Clojure implementation by Rich Hickey, though the
-implementation does differ and several generally highly useful operators
-have been added, with more are to come.
+implementation does differ (also in contrast to some other JS based
+implementations) and several less common, but generally highly useful operators
+have been added, with at least a couple dozen more to come.
 
 Please see the [@thi.ng/iterators](https://github.com/thi-ng/iterators) &
 [@thi.ng/csp](https://github.com/thi-ng/csp) partner modules for related
-functionality, supplementing features of this library.
+functionality, supplementing features of this library. However, this lib has no
+dependencies on either of them. The only dependency is
+[@thi.ng/api](https://github.com/thi-ng/api) for re-using common types &
+interfaces.
 
@@ -46,3 +64,6 @@ Having said this, since 0.8.0 this project largely supersedes the
 
+### Basic usage patterns
+
 ```typescript
+// compose transducer
 xform = tx.comp(
@@ -58,15 +79,42 @@ tx.filter(x => (x & 1) > 0), // odd numbers only
 
-// re-use xform, but collect as set (tx.conj)
+// re-use same xform, but collect as set (tx.conj)
 tx.transduce(xform, tx.conj(), [1, 2, 3, 4, 5, 4, 3, 2, 1]);
 // Set { 3, 9, 15 }
 
-// apply as transforming iterator
-for(let x of tx.iterator(xform, [1, 2, 3, 4, 5])) {
-    console.log(x);
-}
-// 3
-// 9
-// 15
+// or apply as transforming iterator
+// no reduction, only transformations
+[...tx.iterator(xform, [1, 2, 3, 4, 5])]
+// [ 3, 9, 15]
 
-// moving average using sliding window
+// single step execution
+// (currently doesn't work w/ mapcat(), duplicate() and some others)
+// returns undefined if transducer returned no result for this input
+f = tx.step(xform);
+f(1) // 3
+f(2) // undefined
+f(3) // 9
+f(4) // undefined
+f(5) // 15
+f(4) // undefined
+f(3) // undefined
+f(2) // undefined
+f(1) // undefined
+```
+
+### Histogram generation
+
+```typescript
+// use the `frequencies` reducer to create
+// a map counting occurrence of each value
+tx.transduce(tx.map(x => x.toUpperCase()), tx.frequencies(), "hello world")
+// Map { 'H' => 1, 'E' => 1, 'L' => 3, 'O' => 2, ' ' => 1, 'W' => 1, 'R' => 1, 'D' => 1 }
+
+// reduction only (no transform)
+tx.reduce(tx.frequencies(), [1, 1, 1, 2, 3, 4, 4])
+// Map { 1 => 3, 2 => 1, 3 => 1, 4 => 2 }
+```
+
+### Moving average using sliding window
+
+```typescript
 // use nested reduce to compute window averages
@@ -84,4 +132,22 @@ // this combined transducer is also directly
 // [ 2.6, 3.4, 4, 4.6, 5.4, 6.2, 6.8, 7.6, 8.4 ]
+```
 
-// apply inspectors to debug transducer pipeline
+### Benchmark function execution time
+
+```typescript
+// function to test
+fn = () => { for(i=0; i<1e6; i++) let x =Math.cos(i); return x; };
+
+// compute the mean of 100 runs
+tx.transduce(
+    tx.comp(tx.benchmark(), tx.take(100)),
+    tx.mean(),
+    tx.repeatedly(fn)
+);
+// 1.93 (milliseconds)
+```
+
+### Apply inspectors to debug transducer pipeline
+
+```typescript
 // alternatively, use tx.sideEffect() for any side fx
@@ -108,14 +174,7 @@ tx.transduce(
 // [ 3, 5 ]
+```
 
+### CSV parsing
 
-// histogram generation
-tx.transduce(tx.map(x => x.toUpperCase()), tx.frequencies(), "hello world")
-// Map { 'H' => 1, 'E' => 1, 'L' => 3, 'O' => 2, ' ' => 1, 'W' => 1, 'R' => 1, 'D' => 1 }
-
-// reduction only (no transform)
-tx.reduce(tx.frequencies(), [1, 1, 1, 2, 3, 4, 4])
-// Map { 1 => 3, 2 => 1, 3 => 1, 4 => 2 }
-
-
-// CSV parsing
+```typescript
 tx.transduce(
@@ -136,5 +195,7 @@ tx.comp(
 //   { num: 3, alias: 'rs', name: 'rust', id: '110' } ]
+```
 
+### Early termination
 
-// early termination:
+```typescript
 // result is realized after max. 7 values, irrespective of nesting
@@ -147,4 +208,7 @@ tx.transduce(
 // [1, 2, 3, 4, 5, 6, 7]
+```
 
+### Scan operator
 
+```typescript
 // this transducer uses 2 scans (a scan = inner reducer per item)
@@ -158,5 +222,5 @@ // 1) counts incoming values
 xform = tx.comp(
-    tx.scan(tx.count),
-    tx.map(x => [...tx.iterator(tx.repeat(x), [x])]),
-    tx.scan(tx.pushCopy)
+    tx.scan(tx.count()),
+    tx.map(x => [...tx.repeat(x,x)]),
+    tx.scan(tx.pushCopy())
 );
@@ -173,15 +237,58 @@
 // [ [ 1 ], [ 1, 2 ], [ 1, 2, 3 ], [ 1, 2, 3, 4 ] ]
+```
 
-// single step execution (doesn't work w/ mapcat() or repeat())
-f = tx.step(tx.dedupe());
-f(1); // 1
-f(2); // 2
-f(2); // undefined -> skip repetiton
-f(3); // 3
-f(3); // undefined
-f(3); // undefined
-f(1); // 1
+### Streaming hexdump
+
+This is a higher-order transducer, purely composed from other transducers.
+[See code here](https://github.com/thi-ng/transducers/blob/master/src/xform/hex-dump.ts).
+
+```typescript
+src = [65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 33, 48, 49, 50, 51, 126, 122, 121, 120]
+
+[...iterator(hexDump(8, 0x400), src)]
+// [ '00000400 | 41 42 43 44 45 46 47 48 | ABCDEFGH',
+//   '00000408 | 49 4a 21 30 31 32 33 7e | IJ!0123~',
+//   '00000410 | 7a 79 78 00 00 00 00 00 | zyx.....' ]
 ```
 
-### API
+### Bitstream
+
+```typescript
+[...tx.iterator(tx.comp(tx.bits(8), tx.partition(8)), [ 0xf0, 0xaa ])]
+// [ 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0 ]
+
+[...tx.iterator(
+    tx.comp(
+        tx.bits(8),
+        tx.map(x=> x ? "#" : "."),
+        tx.partition(8),
+        tx.map(x=>x.join(""))
+    ),
+    [ 0x00, 0x18, 0x3c, 0x66, 0x66, 0x7e, 0x66, 0x00 ])]
+// [ '........',
+//   '...##...',
+//   '..####..',
+//   '.##..##.',
+//   '.##..##.',
+//   '.######.',
+//   '.##..##.',
+//   '........' ]
+```
+
+### Weighted random choices
+
+```typescript
+tx.transduce(tx.take(10), tx.push(), tx.choices("abcd", [1, 0.5, 0.25, 0.125]))
+// [ 'a', 'a', 'b', 'a', 'a', 'b', 'a', 'c', 'd', 'b' ]
+
+tx.transduce(tx.take(1000), tx.frequencies(), tx.choices("abcd", [1, 0.5, 0.25, 0.125]))
+// Map { 'c' => 132, 'a' => 545, 'b' => 251, 'd' => 72 }
+```
+
+## API
+
+_Documentation is slowly forthcoming in the form of doc comments (incl. code
+examples) for a small, but growing number the functions listed below. Please
+see source code for now._
+
 ### Types
@@ -198,4 +305,4 @@
 Since v0.6.0 the bundled reducers are all wrapped in functions to provide a
-uniform API (and some of them can be preconfigured). However, it's fine to
-define stateless reducers as constant arrays.
+uniform API (and some of them can be preconfigured and/or are stateful
+closures). However, it's fine to define stateless reducers as constant arrays.
 
@@ -329,2 +436,4 @@ ```typescript
 
+#### `bits(wordSize?: number, msbFirst?: boolean): Transducer<number, number>`
+
 #### `cat<T>(): Transducer<T[], T>`
@@ -352,2 +461,4 @@
 
+#### `hexDump(cols?: number, addr?: number): Transducer<number, string>`
+
 #### `indexed<T>(): Transducer<T, [number, T]>`
@@ -373,2 +484,4 @@
 
+#### `padLast<T>(n: number, fill: T): Transducer<T, T>`
+
 #### `partition<T>(size: number, step?: number, all?: boolean): Transducer<T, T[]>`
@@ -382,2 +495,4 @@
 
+#### `rename<A, B>(kmap: IObjectOf<PropertyKey>, rfn?: Reducer<B, [PropertyKey, A]>): Transducer<A[], B>`
+
 #### `sample<T>(prob: number): Transducer<T, T>`
@@ -417,3 +532,3 @@
 
-#### `count(): Reducer<number, number>`
+#### `count(offset?: number, step?: number): Reducer<number, any>`
 
@@ -432,2 +547,4 @@ #### `frequencies<T>(): Reducer<Map<T, number>, T>`
 
+#### `maxCompare<T>(ident: () => T, cmp: Comparator<T> = compare): Reducer<T, T>`
+
 #### `mean(): Reducer<number, number>`
@@ -437,2 +554,4 @@
 
+#### `minCompare<T>(ident: () => T, cmp: Comparator<T> = compare): Reducer<T, T>`
+
 #### `mul(): Reducer<number, number>`
@@ -446,2 +565,4 @@
 
+#### `choices<T>(choices: T[], weights?: number[])`
+
 #### `constantly<T>(x: T): IterableIterator<T>`
@@ -448,0 +569,0 @@

rfn/count.d.ts

 import { Reducer } from "../api";
-export declare function count(): Reducer<number, any>;
+export declare function count(offset?: number, step?: number): Reducer<number, any>;

rfn/count.js

 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-function count() {
+function count(offset = 0, step = 1) {
     return [
-        () => 0,
+        () => offset,
         (acc) => acc,
-        (acc, _) => acc + 1,
+        (acc, _) => acc + step,
     ];
 }
 exports.count = count;

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Improved metrics

Total package byte prevSize

100288

increased by15.06%

Number of package files

179

increased by7.19%

Lines of code

2073

increased by15.17%

Number of lines in readme file

574

increased by26.71%

No dependency changes