From 4b0eec633544d07c053c3880f1312adfcd13a64f Mon Sep 17 00:00:00 2001
From: Karsten Schmidt <k@postspectacular.com>
Date: Tue, 12 Feb 2019 15:37:42 +0000
Subject: [PATCH] refactor(transducers): remove obsolete randomID() &
 weightedRandom()

BREAKING CHANGE: migrate randomID() & weightedRandom() to @thi.ng/random

- update choices() iterator
---
 packages/transducers/src/func/random-id.ts    | 25 -------------
 .../transducers/src/func/weighted-random.ts   | 36 -------------------
 packages/transducers/src/iter/choices.ts      |  8 ++---
 3 files changed, 4 insertions(+), 65 deletions(-)
 delete mode 100644 packages/transducers/src/func/random-id.ts
 delete mode 100644 packages/transducers/src/func/weighted-random.ts

diff --git a/packages/transducers/src/func/random-id.ts b/packages/transducers/src/func/random-id.ts
deleted file mode 100644
index 5979d8aed5..0000000000
--- a/packages/transducers/src/func/random-id.ts
+++ /dev/null
@@ -1,25 +0,0 @@
-import { IRandom, SYSTEM } from "@thi.ng/random";
-import { choices } from "../iter/choices";
-import { take } from "../xform/take";
-
-/**
- * Generates and returns a random string of `len` characters (default
- * 4), plus optional given `prefix` and using only provided `syms`
- * characters (default lowercase a-z).
- *
- * ```
- * randomID()
- * "qgdt"
- *
- * randomID(8, "id-", "0123456789ABCDEF")
- * "id-94EF6E1A"
- * ```
- *
- * @param len
- * @param prefix
- * @param syms
- * @param rnd
- */
-export const randomID =
-    (len = 4, prefix = "", syms = "abcdefghijklmnopqrstuvwxyz", rnd: IRandom = SYSTEM) =>
-        [prefix, ...take(len, choices(syms, null, rnd))].join("");
diff --git a/packages/transducers/src/func/weighted-random.ts b/packages/transducers/src/func/weighted-random.ts
deleted file mode 100644
index 52c26deb4d..0000000000
--- a/packages/transducers/src/func/weighted-random.ts
+++ /dev/null
@@ -1,36 +0,0 @@
-import { IRandom, SYSTEM } from "@thi.ng/random";
-import { repeat } from "../iter/repeat";
-import { zip } from "../iter/zip";
-
-/**
- * Returns a no-arg function which produces a random choice of given
- * weighted `choices`. If `weights` are given, it must be the same size
- * as `choices`. If omitted, each choice will have same probability.
- *
- * https://www.electricmonk.nl/log/2009/12/23/weighted-random-distribution/
- *
- * @param choices
- * @param weights
- */
-export const weightedRandom = <T>(
-    choices: ArrayLike<T> & Iterable<T>,
-    weights?: ArrayLike<number> & Iterable<number>,
-    rnd: IRandom = SYSTEM
-) => {
-    const n = choices.length;
-    const opts = [...zip(choices, weights || repeat(1))].sort((a, b) => b[1] - a[1]);
-    let total = 0, i, r, sum;
-    for (i = 0; i < n; i++) {
-        total += opts[i][1];
-    }
-    return () => {
-        r = rnd.float(total);
-        sum = total;
-        for (i = 0; i < n; i++) {
-            sum -= opts[i][1];
-            if (sum <= r) {
-                return opts[i][0];
-            }
-        }
-    };
-};
diff --git a/packages/transducers/src/iter/choices.ts b/packages/transducers/src/iter/choices.ts
index 73858bdc26..7b21adae5e 100644
--- a/packages/transducers/src/iter/choices.ts
+++ b/packages/transducers/src/iter/choices.ts
@@ -1,6 +1,6 @@
-import { weightedRandom } from "../func/weighted-random";
+import { ensureArray } from "@thi.ng/arrays";
+import { IRandom, SYSTEM, weightedRandom } from "@thi.ng/random";
 import { repeatedly } from "./repeatedly";
-import { IRandom, SYSTEM } from "@thi.ng/random";
 
 /**
  * Returns an infinite iterator of random choices and their (optional)
@@ -19,11 +19,11 @@ import { IRandom, SYSTEM } from "@thi.ng/random";
  */
 export const choices = <T>(
     choices: ArrayLike<T> & Iterable<T>,
-    weights?: ArrayLike<number> & Iterable<number>,
+    weights?: ArrayLike<number>,
     rnd: IRandom = SYSTEM
 ) =>
     repeatedly(
         weights ?
-            weightedRandom(choices, weights, rnd) :
+            weightedRandom(ensureArray(choices), weights, rnd) :
             () => choices[(rnd.float(choices.length) | 0)]
     );