Intersecting number wheels

From Rosetta Code
Task
Intersecting number wheels
You are encouraged to solve this task according to the task description, using any language you may know.

A number wheel has:

  • A name which is an uppercase letter.
  • A set of ordered values which are either numbers or names.


A number is generated/yielded from a named wheel by:

1. Starting at the first value of the named wheel and advancing through subsequent values and wrapping around to the first value to form a "wheel":
1.a If the value is a number, yield it.
1.b If the value is a name, yield the next value from the named wheel
1.c Advance the position of this wheel.

Given the wheel

A: 1 2 3

the number 1 is first generated, then 2, then 3, 1, 2, 3, 1, ...

Note: When more than one wheel is defined as a set of intersecting wheels then the first named wheel is assumed to be the one that values are generated from.

Examples

Given the wheels:

   A: 1 B 2
   B: 3 4

The series of numbers generated starts:

   1, 3, 2, 1, 4, 2, 1, 3, 2, 1, 4, 2, 1, 3, 2...

The intersections of number wheels can be more complex, (and might loop forever), and wheels may be multiply connected.

Note: If a named wheel is referenced more than once by one or many other wheels, then there is only one position of the wheel that is advanced by each and all references to it.

E.g.

 A:  1 D D
 D:  6 7 8
 Generates:
   1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6 ...    
Task

Generate and show the first twenty terms of the sequence of numbers generated from these groups:

   Intersecting Number Wheel group:
     A:  1 2 3
   
   Intersecting Number Wheel group:
     A:  1 B 2
     B:  3 4
   
   Intersecting Number Wheel group:
     A:  1 D D
     D:  6 7 8
   
   Intersecting Number Wheel group:
     A:  1 B C
     B:  3 4
     C:  5 B

Show your output here, on this page.


ALGOL 68

<lang algol68>BEGIN

   # a number wheel element                                                  #
   MODE NWELEMENT = UNION( CHAR # wheel name #, INT # wheel value # );
   # a number wheel                                                          #
   MODE NW = STRUCT( CHAR name, REF INT position, FLEX[ 1 : 0 ]NWELEMENT values );
   # get the next value from a number wheel in an array of number wheels     #
   # note: invalid wheel names will cause subscript range errors             #
   OP   NEXT = ( []NW wheels )INT:
        BEGIN
           INT  result;
           BOOL found := FALSE;
           INT  w     := LWB wheels; # start with the first wheel            #
           WHILE NOT found DO
               IF position OF wheels[ w ] > UPB values OF wheels[ w ] THEN
                   # passed the end of the wheel, go back to the start       #
                   position OF wheels[ w ] := LWB values OF wheels[ w ]
               FI;
               NWELEMENT e = ( values OF wheels[ w ] )[ position OF wheels[ w ] ];
               position OF wheels[ w ] +:= 1;
               CASE e
                 IN ( INT  n ): BEGIN result := n; found := TRUE END
                  , ( CHAR c ): BEGIN
                                    w := LWB wheels;
                                    WHILE name OF wheels[ w ] /= c DO w +:= 1 OD
                                END
               ESAC
           OD;
           result
        END # NEXT # ;
   # prints the first n values from an array of wheels                       #
   PROC show = ( INT n, []NW wheels )VOID:
        BEGIN
           print( ( "First ", whole( n, 0 ), " values from the Intersecting Number Wheels:" ) );
           FOR i FROM LWB wheels TO UPB wheels DO
               print( ( newline, "    ", name OF wheels[ i ], ":" ) );
               FOR v FROM LWB values OF wheels[ i ] TO UPB values OF wheels[ i ] DO
                   CASE ( values OF wheels[ i ] )[ v ]
                     IN ( INT  n ): print( ( " ", whole( n, 0 ) ) )
                      , ( CHAR c ): print( ( " ", c ) )
                   ESAC
               OD
           OD;
           print( ( newline, "        " ) );
           FOR i TO n DO print( ( " ", whole( NEXT wheels, 0 ) ) ) OD;
           print( ( newline, newline ) )
        END # show # ;
   # show some wheels in action                                              #
   show( 20, ( NW( "A", LOC INT := 1, (  1,   2,   3  ) ) ) );
   show( 20, ( NW( "A", LOC INT := 1, (  1,  "B",  2  ) )
             , NW( "B", LOC INT := 1, (  3,   4       ) ) ) );
   show( 20, ( NW( "A", LOC INT := 1, (  1,  "D", "D" ) )
             , NW( "D", LOC INT := 1, (  6,   7,   8  ) ) ) );
   show( 20, ( NW( "A", LOC INT := 1, (  1,  "B", "C" ) )
             , NW( "B", LOC INT := 1, (  3,   4       ) )
             , NW( "C", LOC INT := 1, (  5,  "B"      ) ) ) )

END</lang>

Output:
First 20 values from the Intersecting Number Wheels:
    A: 1 2 3
         1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2

First 20 values from the Intersecting Number Wheels:
    A: 1 B 2
    B: 3 4
         1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3

First 20 values from the Intersecting Number Wheels:
    A: 1 D D
    D: 6 7 8
         1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6

First 20 values from the Intersecting Number Wheels:
    A: 1 B C
    B: 3 4
    C: 5 B
         1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4

C#

<lang csharp>using System; using System.Collections.Generic; using System.Linq;

public static class IntersectingNumberWheels {

   public static void Main() {
       TurnWheels(('A', "123")).Take(20).Print();
       TurnWheels(('A', "1B2"), ('B', "34")).Take(20).Print();
       TurnWheels(('A', "1DD"), ('D', "678")).Take(20).Print();
       TurnWheels(('A', "1BC"), ('B', "34"), ('C', "5B")).Take(20).Print();
   }
   static IEnumerable<char> TurnWheels(params (char name, string values)[] wheels) {
       var data = wheels.ToDictionary(wheel => wheel.name, wheel => wheel.values.Loop().GetEnumerator());
       var primary = data[wheels[0].name];
       while (true) {
           yield return Turn(primary);
       }
       char Turn(IEnumerator<char> sequence) {
           sequence.MoveNext();
           char c = sequence.Current;
           return char.IsDigit(c) ? c : Turn(data[c]);
       }
   }
   static IEnumerable<T> Loop<T>(this IEnumerable<T> seq) {
       while (true) {
           foreach (T element in seq) yield return element;
       }
   }
   static void Print(this IEnumerable<char> sequence) => Console.WriteLine(string.Join(" ", sequence));

}</lang>

Output:
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2
1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3
1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6
1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4

D

<lang d>import std.exception; import std.range; import std.stdio;

struct Wheel {

   private string[] values;
   private uint index;
   invariant {
       enforce(index < values.length, "index out of range");
   }
   this(string[] value...) in {
       enforce(value.length > 0, "Cannot create a wheel with no elements");
   } body {
       values = value;
   }
   enum empty = false;
   auto front() {
       return values[index];
   }
   void popFront() {
       index = (index + 1) % values.length;
   }

}

struct NamedWheel {

   private Wheel[char] wheels;
   char m;
   this(char c, Wheel w) {
       add(c, w);
       m = c;
   }
   void add(char c, Wheel w) {
       wheels[c] = w;
   }
   enum empty = false;
   auto front() {
       auto v = wheels[m].front;
       char c = v[0];
       while ('A' <= c && c <= 'Z') {
           v = wheels[c].front;
           c = v[0];
       }
       return v;
   }
   void popFront() {
       auto v = wheels[m].front;
       wheels[m].popFront;
       char c = v[0];
       while ('A' <= c && c <= 'Z') {
           auto d = wheels[c].front;
           wheels[c].popFront;
           c = d[0];
       }
   }

}

void group1() {

   auto a = Wheel("1", "2", "3");
   a.take(20).writeln;

}

void group2() {

   auto a = Wheel("1", "B", "2");
   auto b = Wheel("3", "4");
   auto n = NamedWheel('A', a);
   n.add('B', b);
   n.take(20).writeln;

}

void group3() {

   auto a = Wheel("1", "D", "D");
   auto d = Wheel("6", "7", "8");
   auto n = NamedWheel('A', a);
   n.add('D', d);
   n.take(20).writeln;

}

void group4() {

   auto a = Wheel("1", "B", "C");
   auto b = Wheel("3", "4");
   auto c = Wheel("5", "B");
   auto n = NamedWheel('A', a);
   n.add('B', b);
   n.add('C', c);
   n.take(20).writeln;

}

void main() {

   group1();
   group2();
   group3();
   group4();

}</lang>

Output:
["1", "2", "3", "1", "2", "3", "1", "2", "3", "1", "2", "3", "1", "2", "3", "1", "2", "3", "1", "2"]
["1", "3", "2", "1", "4", "2", "1", "3", "2", "1", "4", "2", "1", "3", "2", "1", "4", "2", "1", "3"]
["1", "6", "7", "1", "8", "6", "1", "7", "8", "1", "6", "7", "1", "8", "6", "1", "7", "8", "1", "6"]
["1", "3", "5", "1", "4", "3", "1", "4", "5", "1", "3", "4", "1", "3", "5", "1", "4", "3", "1", "4"]

F#

<lang fsharp> // Wheels within wheels. Nigel Galloway: September 30th., 2019. let N(n)=fun()->n let wheel(n:(unit->int)[])=let mutable g= -1 in (fun()->g<-(g+1)%n.Length; n.[g]()) let A1=wheel[|N(1);N(2);N(3)|] for n in 0..20 do printf "%d " (A1()) printfn "" let B2=wheel[|N(3);N(4)|] let A2=wheel[|N(1);B2;N(2)|] for n in 0..20 do printf "%d " (A2()) printfn "" let D3=wheel[|N(6);N(7);N(8)|] let A3=wheel[|N(1);D3;D3|] for n in 0..20 do printf "%d " (A3()) printfn "" let B4=wheel[|N(3);N(4)|] let C4=wheel[|N(5);B4|] let A4=wheel[|N(1);B4;C4|] for n in 0..20 do printf "%d " (A4()) printfn "" </lang>

Output:
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3 2
1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6 7
1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4 5

Factor

An attempt has been made to simplify the interface as much as possible by creating a natural literal syntax for number wheel groups. This should be useful for exploring these types of sequences in the future. nw-parser is an EBNF grammar that turns

"A: 1 B C\nB: 3 4\nC: 5 B"

into

{
    { "A" T{ number-wheel { seq T{ circular { seq { 1 "B" "C" } } } } { i 0 } } }
    { "B" T{ number-wheel { seq T{ circular { seq { 3 4 } } } } { i 0 } } }
    { "C" T{ number-wheel { seq T{ circular { seq { 5 "B" } } } } { i 0 } } }
}

⁠— a dictionary-like structure that is transformed into a lazy list which yields the expected sequence elements.

Works with: Factor version 0.99 2019-07-10

<lang factor>USING: accessors assocs circular io kernel lists lists.lazy math math.parser multiline peg.ebnf prettyprint prettyprint.custom sequences strings ; IN: rosetta-code.number-wheels

TUPLE: group pretty list ;

C: <group> group

M: group pprint* pretty>> write ;

TUPLE: number-wheel seq i ;

<number-wheel> ( seq -- number-wheel )
   <circular> 0 number-wheel boa ;
yield ( assoc -- n )
   dup first first [ dup integer? ]
   [ dupd of [ i>> ] [ [ 1 + ] change-i seq>> nth ] bi ] until
   nip ;
number-wheel>lazy ( assoc -- list )
   0 lfrom swap [ yield nip ] curry lmap-lazy ;

EBNF: nw-parser [=[

   num   = [0-9]+ => [[ >string string>number ]]
   name  = [a-zA-Z]+ => [[ >string ]]
   wheel = (" "~ (num | name))+ "\n"?
         => [[ but-last first <number-wheel> ]]
   group = (name ":"~ wheel)+ => [[ number-wheel>lazy ]]

]=]

SYNTAX: NUMBER-WHEELS: parse-here dup nw-parser <group> suffix! ;

.take ( n group -- )
   list>> ltake list>array [ pprint bl ] each "..." print ;</lang>

Now the interface defined above may be used: <lang factor>USING: generalizations io kernel prettyprint rosetta-code.number-wheels ;

NUMBER-WHEELS: A: 1 2 3

NUMBER-WHEELS: A: 1 B 2 B: 3 4

NUMBER-WHEELS: A: 1 D D D: 6 7 8

NUMBER-WHEELS: A: 1 B C B: 3 4 C: 5 B

[

   "Intersecting number wheel group:" print
   [ . ] [ "Generates:" print 20 swap .take nl ] bi

] 4 napply</lang>

Output:
Intersecting number wheel group:
A: 1 2 3
Generates:
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 ...

Intersecting number wheel group:
A: 1 B 2
B: 3 4
Generates:
1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3 ...

Intersecting number wheel group:
A: 1 D D
D: 6 7 8
Generates:
1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6 ...

Intersecting number wheel group:
A: 1 B C
B: 3 4
C: 5 B
Generates:
1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4 ...

Go

<lang go>package main

import (

   "fmt"
   "sort"
   "strconv"

)

type wheel struct {

   next   int
   values []string

}

type wheelMap = map[string]wheel

func generate(wheels wheelMap, start string, maxCount int) {

   count := 0
   w := wheels[start]
   for {
       s := w.values[w.next]
       v, err := strconv.Atoi(s)
       w.next = (w.next + 1) % len(w.values)
       wheels[start] = w
       if err == nil {
           fmt.Printf("%d ", v)
           count++
           if count == maxCount {
               fmt.Println("...\n")
               return
           }
       } else {
           for {
               w2 := wheels[s]
               ss := s
               s = w2.values[w2.next]
               w2.next = (w2.next + 1) % len(w2.values)
               wheels[ss] = w2
               v, err = strconv.Atoi(s)
               if err == nil {
                   fmt.Printf("%d ", v)
                   count++
                   if count == maxCount {
                       fmt.Println("...\n")
                       return
                   }
                   break
               }
           }
       }
   }

}

func printWheels(wheels wheelMap) {

   var names []string
   for name := range wheels {
       names = append(names, name)
   }
   sort.Strings(names)
   fmt.Println("Intersecting Number Wheel group:")
   for _, name := range names {
       fmt.Printf("  %s: %v\n", name, wheels[name].values)
   }
   fmt.Print("  Generates:\n    ")

}

func main() {

   wheelMaps := []wheelMap{
       {
           "A": {0, []string{"1", "2", "3"}},
       },
       {
           "A": {0, []string{"1", "B", "2"}},
           "B": {0, []string{"3", "4"}},
       },
       {
           "A": {0, []string{"1", "D", "D"}},
           "D": {0, []string{"6", "7", "8"}},
       },
       {
           "A": {0, []string{"1", "B", "C"}},
           "B": {0, []string{"3", "4"}},
           "C": {0, []string{"5", "B"}},
       },
   }
   for _, wheels := range wheelMaps {
       printWheels(wheels)
       generate(wheels, "A", 20)
   }

}</lang>

Output:
Intersecting Number Wheel group:
  A: [1 2 3]
  Generates:
    1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 ...

Intersecting Number Wheel group:
  A: [1 B 2]
  B: [3 4]
  Generates:
    1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3 ...

Intersecting Number Wheel group:
  A: [1 D D]
  D: [6 7 8]
  Generates:
    1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6 ...

Intersecting Number Wheel group:
  A: [1 B C]
  B: [3 4]
  C: [5 B]
  Generates:
    1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4 ...

Haskell

Defining a unit movement of the interlocking wheels as a recursive descent, terminating at the first digit found, and printing a map-accumulation of that recursion over a list of given length but arbitrary content.

<lang haskell>import qualified Data.Map.Strict as M import Data.Maybe (fromMaybe) import Data.List (mapAccumL) import Data.Char (isDigit) import Data.Bool (bool)


clockWorkTick :: M.Map Char String -> (M.Map Char String, Char) clockWorkTick = flip click 'A'

 where
   click wheels name =
     let wheel = fromMaybe ['?'] (M.lookup name wheels)
         v = head wheel
     in bool
          click
          (,)
          (isDigit v || '?' == v)
          (M.insert name (leftRotate wheel) wheels)
          v

leftRotate :: [a] -> [a] leftRotate = take . length <*> (tail . cycle)


-- TEST --------------------------------------------------- main :: IO () main = do

 let wheelSets =
       [ [('A', "123")]
       , [('A', "1B2"), ('B', "34")]
       , [('A', "1DD"), ('D', "678")]
       , [('A', "1BC"), ('B', "34"), ('C', "5B")]
       ]
 putStrLn "State of each wheel-set after 20 clicks:\n"
 mapM_ print $
   fmap
     (flip (mapAccumL (const . clockWorkTick)) (replicate 20 ' ') . M.fromList)
     wheelSets
 putStrLn "\nInitial state of the wheel-sets:\n"
 mapM_ print wheelSets</lang>
Output:
State of each wheel-set after 20 clicks:

(fromList [('A',"312")],"12312312312312312312")
(fromList [('A',"21B"),('B',"43")],"13214213214213214213")
(fromList [('A',"D1D"),('D',"786")],"16718617816718617816")
(fromList [('A',"C1B"),('B',"34"),('C',"5B")],"13514314513413514314")

Initial state of the wheel-sets:

[('A',"123")]
[('A',"1B2"),('B',"34")]
[('A',"1DD"),('D',"678")]
[('A',"1BC"),('B',"34"),('C',"5B")]

JavaScript

Map-accumulation of a recursive digit-search, over an array of given length and arbitrary contents.

Translation of: Haskell
Translation of: Python

<lang javascript>(() => {

   'use strict';
   // main :: IO ()
   const main = () => {
       // clockWorkTick :: Dict -> (Dict, Char)
       const clockWorkTick = wheelMap => {
           // The new configuration of the wheels, tupled with
           // a digit found by recursive descent from a single
           // click of the first wheel.
           const click = wheels => wheelName => {
               const
                   wheel = wheels[wheelName] || ['?'],
                   v = wheel[0];
               return bool(click)(Tuple)(isDigit(v) || '?' === v)(
                   insertDict(wheelName)(
                       leftRotate(wheel)
                   )(wheels)
               )(v);
           };
           return click(wheelMap)('A');
       };
       // leftRotate ::[a] -> [a]
       const leftRotate = xs =>
           // The head of the list appended
           // to the tail of of the list.
           0 < xs.length ? (
               xs.slice(1).concat(xs[0])
           ) : [];


       // TEST -------------------------------------------
       // State of each wheel-set after 20 clicks,
       // paired with the resulting series of characters.
       const tuple = uncurry(Tuple);
       const wheelLists = [
           [tuple('A', '123')],
           [tuple('A', '1B2'), tuple('B', '34')],
           [tuple('A', '1DD'), tuple('D', '678')],
           [tuple('A', '1BC'), tuple('B', '34'), tuple('C', '5B')]
       ];
       console.log([
           'Series and state of each wheel-set after 20 clicks:\n',
           unlines(
               map(tuples => showWheels(
                   mapAccumL(
                       compose(constant, clockWorkTick)
                   )(dictFromList(tuples))(replicate(20)())
               ))(wheelLists)
           ),
           '\nInitial state of each wheel-set:\n',
           map(map(compose(
               JSON.stringify,
               dictFromList,
               x => [Array.from(x)]
           )))(wheelLists).join('\n')
       ].join('\n'));
   };
   // DISPLAY FORMATTING ---------------------------------
   // showWheels :: (Dict, [Char]) -> String
   const showWheels = tpl =>
       JSON.stringify(
           Array.from(secondArrow(concat)(tpl))
       );
   // GENERIC FUNCTIONS ----------------------------------
   // Tuple (,) :: a -> b -> (a, b)
   const Tuple = a => b => ({
       type: 'Tuple',
       '0': a,
       '1': b,
       length: 2
   });
   // bool :: a -> a -> Bool -> a
   const bool = f => t => p =>
       p ? t : f;
   // compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
   const compose = (...fs) =>
       x => fs.reduceRight((a, f) => f(a), x);
   // concat :: a -> [a]
   // concat :: [String] -> String
   const concat = xs =>
       0 < xs.length ? (() => {
           const unit = 'string' !== typeof xs[0] ? (
               []
           ) : ;
           return unit.concat.apply(unit, xs);
       })() : [];
   // constant :: a -> b -> a
   const constant = k => _ => k;
   // dictFromList :: [(k, v)] -> Dict
   const dictFromList = kvs =>
       Object.fromEntries(kvs);
   // secondArrow :: (a -> b) -> ((c, a) -> (c, b))
   const secondArrow = f => xy =>
       // A function over a simple value lifted
       // to a function over a tuple.
       // f (a, b) -> (a, f(b))
       Tuple(xy[0])(
           f(xy[1])
       );
   // insertDict :: String -> a -> Dict -> Dict
   const insertDict = k => v => dct =>
       Object.assign({}, dct, {
           [k]: v
       });
   // isDigit :: Char -> Bool
   const isDigit = c => {
       const n = c.codePointAt(0);
       return 48 <= n && 57 >= n;
   };
   // map :: (a -> b) -> [a] -> [b]
   const map = f => xs =>
       (Array.isArray(xs) ? (
           xs
       ) : xs.split()).map(f);
   // Map-accumulation is a combination of map and a catamorphism;
   // it applies a function to each element of a list, passing an
   // accumulating parameter from left to right, and returning a final
   // value of this accumulator together with the new list.
   // mapAccumL :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])
   const mapAccumL = f => acc => xs =>
       xs.reduce((a, x) => {
           const pair = f(a[0])(x);
           return Tuple(pair[0])(a[1].concat(pair[1]));
       }, Tuple(acc)([]));
   // replicate :: Int -> a -> [a]
   const replicate = n => x =>
       Array.from({
           length: n
       }, () => x);
   // uncurry :: (a -> b -> c) -> ((a, b) -> c)
   const uncurry = f =>
       (x, y) => f(x)(y);
   // unlines :: [String] -> String
   const unlines = xs => xs.join('\n');
   // MAIN ---
   return main();

})();</lang>

Output:
Series and state of each wheel-set after 20 clicks:

[{"A":"312"},"12312312312312312312"]
[{"A":"21B","B":"43"},"13214213214213214213"]
[{"A":"D1D","D":"786"},"16718617816718617816"]
[{"A":"C1B","B":"34","C":"5B"},"13514314513413514314"]

Initial state of each wheel-set:

{"A":"123"}
{"A":"1B2"},{"B":"34"}
{"A":"1DD"},{"D":"678"}
{"A":"1BC"},{"B":"34"},{"C":"5B"}

Julia

<lang julia>const d1 = Dict("A" => [["1", "2", "3"], 1]) const d2 = Dict("A" => [["1", "B", "2"], 1], "B" => [["3", "4"], 1]) const d3 = Dict("A" => [["1", "D", "D"], 1], "D" => [["6", "7", "8"], 1]) const d4 = Dict("A" => [["1", "B", "C"], 1], "B" => [["3", "4"], 1],

   "C" => [["5", "B"], 1])

function getvalue!(wheelname, allwheels)

   wheel = allwheels[wheelname]
   s = wheel[1][wheel[2]]
   wheel[2] = mod1(wheel[2] + 1, length(wheel[1]))
   return haskey(allwheels, s) ? getvalue!(s, allwheels) : s

end

function testwheels(wheels, numterms = 20, firstwheel = "A")

   println("\nNumber Wheels:")
   for k in sort(collect(keys(wheels)))
       print("$k: [")
       for s in wheels[k][1]
           print(s, " ")
       end
       println("\b]")
   end
   print("Output: ")
   for _ in 1:numterms
       print(getvalue!(firstwheel, wheels), " ")
   end
   println("...")

end

foreach(testwheels, [d1, d2, d3, d4])

</lang>

Output:
Number Wheels:
A: [1 2 3]
Output: 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 ...

Number Wheels:
A: [1 B 2]
B: [3 4]
Output: 1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3 ...

Number Wheels:
A: [1 D D]
D: [6 7 8]
Output: 1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6 ...

Number Wheels:
A: [1 B C]
B: [3 4]
C: [5 B]
Output: 1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4 ...

Perl

Translation of: Julia

<lang perl>use strict; use warnings; use feature 'say';

sub get_next {

   my($w,%wheels) = @_;
   my $wh = \@{$wheels{$w}}; # reference, not a copy
   my $value = $$wh[0][$$wh[1]];
   $$wh[1] = ($$wh[1]+1) % @{$$wh[0]};
   defined $wheels{$value} ? get_next($value,%wheels) : $value;

}

sub spin_wheels {

   my(%wheels) = @_;
   say "$_: " . join ', ', @{${$wheels{$_}}[0]} for sort keys %wheels;
   print get_next('A', %wheels) . ' ' for 1..20; print "\n\n";

}

spin_wheels(%$_) for (

{'A' => [['1', '2', '3'], 0]},
{'A' => [['1', 'B', '2'], 0], 'B' => [['3', '4'], 0]},
{'A' => [['1', 'D', 'D'], 0], 'D' => [['6', '7', '8'], 0]},
{'A' => [['1', 'B', 'C'], 0], 'B' => [['3', '4'], 0], 'C' => [['5', 'B'], 0]},

);</lang>

Output:
A: 1, 2, 3
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2

A: 1, B, 2
B: 3, 4
1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3

A: 1, D, D
D: 6, 7, 8
1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6

A: 1, B, C
B: 3, 4
C: 5, B
1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4

Perl 6

A succinct Perl 6 example using a few additional language features. Wheels are implemented as infinite repeating sequences, allowing a single iterator to keep track of the current position. This means the code contains no position tracking whatsoever. <lang perl6>

  1. | advance rotates a named wheel $n by consuming an item from an infinite sequence. It is called
  2. | from within a gather block and so can use take in order to construct an infinite, lazy sequence
  3. | of result values

sub advance($g, $n) { given $g{$n}.pull-one { when /\d/ { take $_ } default { samewith $g, $_ } # samewith re-calls this function with new parameters } }

  1. | Input groups are a hash containing each wheel name as the key, and a list of values constructed
  2. | using <> to split on whitespace. They are transformed using xx * to repeat the list infinitely.
  3. | We then retrieve the underlying iterator in order for wheel position to be persistent. Each group
  4. | is then aggregated into a lazy output sequence using an infinite loop inside a gather block.

[ {A => <1 2 3>}, {A => <1 B 2>, B => <3 4>}, {A => <1 D D>, D => <6 7 8>}, {A => <1 B C>, B => <3 4>, C => <5 B>}, ] #| %() converts a list of pairs produced by map into a hash. $^k and $^v are implicit variables. #| They are processed in alphabetical order and make the block arity 2, called with two vars. #| .kv gets the list of wheel names and wheel values from the input entry ==> map({ %(.kv.map: { $^k => (|$^v xx *).iterator }) }) #| gather constructs a lazy sequence, in which we infinitely loop advancing wheel A ==> map({ gather { loop { advance $_, 'A' }} }) #| state variables are only initialised once, and are kept between invocations. ==> map({ state $i = 1; say "Group {$i++}, First 20 values: $_[^20]" })

</lang>

Output:
Group 1, First 20 values: 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2
Group 2, First 20 values: 1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3
Group 3, First 20 values: 1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6
Group 4, First 20 values: 1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4

Phix

<lang Phix>function terms(sequence wheels, integer n)

   sequence res = repeat(' ',n),
            pos = repeat(2,length(wheels)),
            wvs = vslice(wheels,1)
   integer wheel = 1, rdx = 1
   while rdx<=n do
       integer p = pos[wheel],
               c = wheels[wheel][p]
       p = iff(p=length(wheels[wheel])?2:p+1)
       pos[wheel] = p
       if c>'9' then
           wheel = find(c,wvs)
       else
           res[rdx] = c
           rdx += 1
           wheel = 1
       end if
   end while
   return res

end function

constant wheels = {{"A123"},

                  {"A1B2","B34"},
                  {"A1DD","D678"},
                  {"A1BC","B34","C5B"}}

for i=1 to length(wheels) do

   ?terms(wheels[i],20)

end for</lang>

Output:
"12312312312312312312"
"13214213214213214213"
"16718617816718617816"
"13514314513413514314"

Python

Python: Original class and generator based

<lang python>from itertools import islice

class INW():

   """
   Intersecting Number Wheels
   represented as a dict mapping
   name to tuple of values.
   """
   def __init__(self, **wheels):
       self._wheels = wheels
       self.isect = {name: self._wstate(name, wheel) 
                     for name, wheel in wheels.items()}
   
   def _wstate(self, name, wheel):
       "Wheel state holder"
       assert all(val in self._wheels for val in wheel if type(val) == str), \
              f"ERROR: Interconnected wheel not found in {name}: {wheel}"
       pos = 0
       ln = len(wheel)
       while True:
           nxt, pos = wheel[pos % ln], pos + 1
           yield next(self.isect[nxt]) if type(nxt) == str else nxt
               
   def __iter__(self):
       base_wheel_name = next(self.isect.__iter__())
       yield from self.isect[base_wheel_name]
       
   def __repr__(self):
       return f"{self.__class__.__name__}({self._wheels})"
   
   def __str__(self):
       txt = "Intersecting Number Wheel group:"
       for name, wheel in self._wheels.items():
           txt += f"\n  {name+':':4}" + ' '.join(str(v) for v in wheel)
       return txt

def first(iter, n):

   "Pretty print first few terms"
   return ' '.join(f"{nxt}" for nxt in islice(iter, n))

if __name__ == '__main__':

   for group in[
     {'A': (1, 2, 3)},
     {'A': (1, 'B', 2),
      'B': (3, 4)},
     {'A': (1, 'D', 'D'),
      'D': (6, 7, 8)},
     {'A': (1, 'B', 'C'),
      'B': (3, 4),
      'C': (5, 'B')}, # 135143145...
    ]:
       w = INW(**group)
       print(f"{w}\n  Generates:\n    {first(w, 20)} ...\n")</lang>
Output:
Intersecting Number Wheel group:
  A:  1 2 3
  Generates:
    1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 ...

Intersecting Number Wheel group:
  A:  1 B 2
  B:  3 4
  Generates:
    1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3 ...

Intersecting Number Wheel group:
  A:  1 D D
  D:  6 7 8
  Generates:
    1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6 ...

Intersecting Number Wheel group:
  A:  1 B C
  B:  3 4
  C:  5 B
  Generates:
    1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4 ...

Python: Simplified procedural

<lang python>def nextfrom(w, name):

   while True:
       nxt, w[name] = w[name][0], w[name][1:] + w[name][:1]
       if '0' <= nxt[0] <= '9':
           return nxt
       name = nxt
           

if __name__ == '__main__':

   for group in 

A: 1 2 3 A: 1 B 2; B: 3 4 A: 1 D D; D: 6 7 8 A: 1 B C; B: 3 4; C: 5 B.strip().split('\n'):

       print(f"Intersecting Number Wheel group:\n  {group}")
       wheel, first = {}, None
       for w in group.strip().split(';'):
           name, *values = w.strip().split()
           wheel[name[:-1]] = values
           first = name[:-1] if first is None else first
       gen = ' '.join(nextfrom(wheel, first) for i in range(20))
       print(f"  Generates:\n    {gen} ...\n")</lang>
Output:
Intersecting Number Wheel group:
  A: 1 2 3
  Generates:
    1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 ...

Intersecting Number Wheel group:
  A: 1 B 2; B: 3 4
  Generates:
    1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3 ...

Intersecting Number Wheel group:
  A: 1 D D; D: 6 7 8
  Generates:
    1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6 ...

Intersecting Number Wheel group:
  A: 1 B C; B: 3 4; C: 5 B
  Generates:
    1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4 ...


And Again

This time the nextfromr function is recursive and it will only work for single character names and numbers due to character string rotation being used.
Input is just a list of Python dicts, and depends on c-python dicts being odered by key insertion order.

<lang python>def nextfromr(w, name):

   nxt, w[name] = w[name][0], w[name][1:] + w[name][:1]
   return nxt if '0' <= nxt[0] <= '9' else nextfromr(w, nxt)
           

if __name__ == '__main__':

   for group in [{'A': '123'},
                 {'A': '1B2', 'B': '34'},
                 {'A': '1DD', 'D': '678'},
                 {'A': '1BC', 'B': '34', 'C': '5B'},]:
       print(f"Intersecting Number Wheel group:\n  {group}")
       first = next(group.__iter__())
       gen = ' '.join(nextfromr(group, first) for i in range(20))
       print(f"  Generates:\n   {gen} ...\n")</lang>
Output:
Intersecting Number Wheel group:
  {'A': '123'}
  Generates:
   1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 ...

Intersecting Number Wheel group:
  {'A': '1B2', 'B': '34'}
  Generates:
   1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3 ...

Intersecting Number Wheel group:
  {'A': '1DD', 'D': '678'}
  Generates:
   1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6 ...

Intersecting Number Wheel group:
  {'A': '1BC', 'B': '34', 'C': '5B'}
  Generates:
   1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4 ...

Python: Functional composition

Defining a unit rotation of the wheel-set as a recursive descent, and taking a map-accumulation of this recursion over a list of specific length and arbitrary content.

Translation of: Haskell
Works with: Python version 3.7

<lang python>Intersecting number wheels

from functools import reduce from itertools import cycle, islice


  1. clockWorkTick :: Dict -> (Dict, Char)

def clockWorkTick(wheelMap):

   The new state of the wheels, tupled with a
      digit found by recursive descent from a single
      click of the first wheel.
   def click(wheels):
       def go(wheelName):
           wheel = wheels.get(wheelName, ['?'])
           v = wheel[0]
           return (Tuple if v.isdigit() or '?' == v else click)(
               insertDict(wheelName)(leftRotate(wheel))(wheels)
           )(v)
       return lambda name: go(name)
   return click(wheelMap)('A')


  1. leftRotate :: [a] -> String

def leftRotate(xs):

    A string shifted cyclically towards
       the left by one position.
   
   return .join(islice(cycle(xs), 1, 1 + len(xs)))


  1. TEST ----------------------------------------------------
  2. main :: IO ()

def main():

   First twenty values from each set of test wheels.
   wheelMaps = [dict(kvs) for kvs in [
       [('A', "123")],
       [('A', "1B2"), ('B', "34")],
       [('A', "1DD"), ('D', "678")],
       [('A', "1BC"), ('B', "34"), ('C', "5B")]
   ]]
   print('New state of wheel sets, after 20 clicks of each:\n')
   for wheels, series in [
           mapAccumL(compose(const)(clockWorkTick))(
               dct
           )(' ' * 20) for dct in wheelMaps
   ]:
       print((wheels, .join(series)))
   print('\nInital states:')
   for x in wheelMaps:
       print(x)


  1. GENERIC -------------------------------------------------
  1. Tuple (,) :: a -> b -> (a, b)

def Tuple(x):

   Constructor for a pair of values,
      possibly of two different types.
   
   return lambda y: (
       x + (y,)
   ) if isinstance(x, tuple) else (x, y)


  1. compose (<<<) :: (b -> c) -> (a -> b) -> a -> c

def compose(g):

   Right to left function composition.
   return lambda f: lambda x: g(f(x))


  1. const :: a -> b -> a

def const(k):

   The latter of two arguments,
      with the first discarded.
   
   return lambda _: k


  1. insertDict :: String -> a -> Dict -> Dict

def insertDict(k):

   A dictionary updated with a (k, v) pair.
   def go(v, dct):
       dup = dict(dct)
       dup.update({k: v})
       return dup
   return lambda v: lambda dct: go(v, dct)


  1. mapAccumL :: (acc -> x -> (acc, y)) -> acc -> [x] -> (acc, [y])

def mapAccumL(f):

   A tuple of an accumulation and a list derived by a
      combined map and fold,
      with accumulation from left to right.
   
   def go(a, x):
       tpl = f(a[0])(x)
       return (tpl[0], a[1] + [tpl[1]])
   return lambda acc: lambda xs: (
       reduce(go, xs, (acc, []))
   )


  1. MAIN ---

if __name__ == '__main__':

   main()</lang>
Output:
New state of wheel sets, after 20 clicks of each:

({'A': '312'}, '12312312312312312312')
({'A': '21B', 'B': '43'}, '13214213214213214213')
({'A': 'D1D', 'D': '786'}, '16718617816718617816')
({'A': 'C1B', 'B': '34', 'C': '5B'}, '13514314513413514314')

Inital states:
{'A': '123'}
{'A': '1B2', 'B': '34'}
{'A': '1DD', 'D': '678'}
{'A': '1BC', 'B': '34', 'C': '5B'}

REXX

Quite a bit of the REXX code deals with detecting of errors   (and issuing error messages)   in the specification and
generation/construction of the wheel sets.

This REXX program uses   numbers   (any form),   not   digits   (for the values on the wheels). <lang rexx>/*REXX program expresses numbers from intersecting number wheels (or wheel sets). */ @.= /*initialize array to hold the wheels. */ parse arg lim @.1 /*obtain optional arguments from the CL*/ if lim= | lim="," then lim= 20 /*Not specified? Then use the default.*/ if @.1= | @.1="," then do; @.1= ' A: 1 2 3 '

                              @.2= ' A:  1 B 2,    B:  3 4 '
                              @.3= ' A:  1 D D,    D:  6 7 8 '
                              @.4= ' A:  1 B C,    B:  3 4,    C:  5 B '
                         end
      do i=1  while @.i\=;  call build        /*construct the wheel set  (gear sets).*/
                              call run          /*execute    "    "    "      "    "   */
      end   /*i*/

exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ error: say; say; say '***error***' arg(1); say; say; exit 12 isLet: return datatype( arg(1), 'M') & length( arg(1) )==1 isNum: return datatype( arg(1), 'N') /*──────────────────────────────────────────────────────────────────────────────────────*/ build: @wn= 'wheel name'; first=; @wnnfbac= 'wheel name not followed by a colon:'

      @gn= 'gear name' ;     gear.=;      say copies('═', 79)
      say 'building wheel group for: '    @.i;    wheels= space(@.i);        upper wheels
         do y=1  while wheels\=;  parse var wheels  w gears ',' wheels;    L= length(w)
         if L==2  then do;  !.y= left(w, 1)              /*obtain the 1-char gear name.*/
                            if right(w, 1)\==':'  then call error @wnnfbac  w
                            if \isLet(!.y)        then call error @wn "not a letter:"  w
                       end
                  else                       call error "first token isn't a" @wn':'   w
         if y==1  then first= !.1               /*Is this is the 1st wheel set?  Use it*/
         if first==                   then call error "no wheel name was specified."
         n= !.y                                 /*obtain the name of the 1st wheel set.*/
         gear.n.0= 1                            /*initialize default 1st gear position.*/
         say '   setting gear.name:'  n   '    gears=' gears
            do g=1  for words(gears);         _= word(gears, g)
            if isNum(_) | isLet(_)  then do;  gear.n.g= _;  iterate;  end
            call error  @gn  "isn't a number or a gear name:"  _
            end   /*g*/
         end      /*y*/;        return

/*──────────────────────────────────────────────────────────────────────────────────────*/ run: say; say center(' running the wheel named ' first" ", 79, "─"); $=

       do #=0  by 0  until words($)==lim;           n= first
       z= gear.n.0;               x= gear.n.z;      z= z + 1
       gear.n.0= z;      if gear.n.z==  then gear.n.0= 1
       if isNum(x)  then do;      $= $ x;    iterate;    end  /*found a number, use it.*/
       xx= x                                  /*different gear, keep switching until #.*/
          do forever;            nn= xx
          if gear.nn.0==  then call error "a gear is using an unknown gear name:"   x
          zz= gear.nn.0;         xx= gear.nn.zz
          zz= zz + 1;  gear.nn.0= zz;  if gear.nn.zz==  then gear.nn.0= 1
          if isNum(xx)  then do; $= $ xx;  iterate #;  end
          end                                 /* [↑]  found a number,  now use  FIRST. */
       end   /*until*/
    say '('lim "results): " strip($);         say;          say;          return</lang>
output   when using the default inputs:
═══════════════════════════════════════════════════════════════════════════════
building wheel group for:   A:  1 2 3
   setting gear.name: A     gears= 1 2 3

───────────────────────── running the wheel named  A ──────────────────────────
(20 results):  1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2


═══════════════════════════════════════════════════════════════════════════════
building wheel group for:   A:  1 B 2,    B:  3 4
   setting gear.name: A     gears= 1 B 2
   setting gear.name: B     gears= 3 4

───────────────────────── running the wheel named  A ──────────────────────────
(20 results):  1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3


═══════════════════════════════════════════════════════════════════════════════
building wheel group for:   A:  1 D D,    D:  6 7 8
   setting gear.name: A     gears= 1 D D
   setting gear.name: D     gears= 6 7 8

───────────────────────── running the wheel named  A ──────────────────────────
(20 results):  1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6


═══════════════════════════════════════════════════════════════════════════════
building wheel group for:   A:  1 B C,    B:  3 4,    C:  5 B
   setting gear.name: A     gears= 1 B C
   setting gear.name: B     gears= 3 4
   setting gear.name: C     gears= 5 B

───────────────────────── running the wheel named  A ──────────────────────────
(20 results):  1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4

Visual Basic .NET

Translation of: C#

<lang vbnet>Imports System.Runtime.CompilerServices

Module Module1

   <Extension()>
   Iterator Function Loopy(Of T)(seq As IEnumerable(Of T)) As IEnumerable(Of T)
       While True
           For Each element In seq
               Yield element
           Next
       End While
   End Function
   Iterator Function TurnWheels(ParamArray wheels As (name As Char, values As String)()) As IEnumerable(Of Char)
       Dim data = wheels.ToDictionary(Function(wheel) wheel.name, Function(wheel) wheel.values.Loopy.GetEnumerator)
       Dim primary = data(wheels(0).name)
       Dim Turn As Func(Of IEnumerator(Of Char), Char) = Function(sequence As IEnumerator(Of Char))
                                                             sequence.MoveNext()
                                                             Dim c = sequence.Current
                                                             Return If(Char.IsDigit(c), c, Turn(data(c)))
                                                         End Function
       While True
           Yield Turn(primary)
       End While
   End Function
   <Extension()>
   Sub Print(sequence As IEnumerable(Of Char))
       Console.WriteLine(String.Join(" ", sequence))
   End Sub
   Sub Main()
       TurnWheels(("A", "123")).Take(20).Print()
       TurnWheels(("A", "1B2"), ("B", "34")).Take(20).Print()
       TurnWheels(("A", "1DD"), ("D", "678")).Take(20).Print()
       TurnWheels(("A", "1BC"), ("B", "34"), ("C", "5B")).Take(20).Print()
   End Sub

End Module</lang>

Output:
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2
1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3
1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6
1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4

zkl

<lang zkl>fcn intersectingNumberWheelsW(wheels){ // ("A":(a,b,"C"), "C":(d,e) ...)

  ws:=wheels.pump(Dictionary(),fcn([(k,v)]){ return(k,Walker.cycle(v)) });  // new Dictionary
  Walker.zero().tweak(fcn(w,wheels){
     while(1){

w=wheels[w].next(); // increment wheel w if(Int.isType(w)) return(w);

     }      
  }.fp("A",ws))	// assume wheel A exists and is always first

}</lang> <lang zkl>wheelSets:=T( Dictionary("A",T(1,2,3)), Dictionary("A",T(1,"B",2), "B",T(3,4)), Dictionary("A",T(1,"D","D"), "D",T(6,7,8)), Dictionary("A",T(1,"B","C"), "C",T(5,"B"), "B",T(3,4)) ); foreach ws in (wheelSets){

  println("Wheel set:");
  ws.pump(String,fcn([(k,v)]){ "  %s: %s\n".fmt(k,v.concat(" ")) }).print();
  println("-->",intersectingNumberWheelsW(ws).walk(20).concat(" "));

}</lang>

Output:
Wheel set:
  A: 1 2 3
-->1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2
Wheel set:
  A: 1 B 2
  B: 3 4
-->1 3 2 1 4 2 1 3 2 1 4 2 1 3 2 1 4 2 1 3
Wheel set:
  A: 1 D D
  D: 6 7 8
-->1 6 7 1 8 6 1 7 8 1 6 7 1 8 6 1 7 8 1 6
Wheel set:
  A: 1 B C
  C: 5 B
  B: 3 4
-->1 3 5 1 4 3 1 4 5 1 3 4 1 3 5 1 4 3 1 4