# Selection

Cycle through values over time for evolving patterns.

## Step Cycle

`cycle` cycles through values based on step runs:

```forth
60 64 67 3 cycle note  ( cycle through C, E, G )
```

Each time the step runs, it picks the next value.

## Pattern Cycle

`pcycle` cycles based on pattern iteration:

```forth
60 64 67 3 pcycle note  ( change note each pattern loop )
```

## Emit-Time Cycle

`tcycle` creates a cycle list resolved at emit time, useful with `.!`:

```forth
60 64 67 3 tcycle note 3 .!  ( emit C, E, G in sequence )
```

## Examples

Rotating bass notes:

```forth
"bass" s
  c3 e3 g3 b3 4 cycle note
.
```

Evolving pattern over loops:

```forth
"lead" s
  0.5 1.0 0.75 0.25 4 pcycle gain
.
```

Arpeggiated chord:

```forth
"pluck" s
  c4 e4 g4 c5 4 tcycle note 4 .!
```

## Words

| Word | Stack | Description |
|------|-------|-------------|
| `cycle` | (v1..vn n -- val) | Cycle by step runs |
| `pcycle` | (v1..vn n -- val) | Cycle by pattern iteration |
| `tcycle` | (v1..vn n -- list) | Create cycle list for emit-time |