# struct

Type: `struct :: Pattern Bool -> Pattern a -> Pattern a`

**struct** places a rhythmic 'boolean' structure on the pattern you given it.

For example:

```
d1 $ struct ("t ~ t*2 ~") $ sound "cp"
```

... is the same as ...

```
d1 $ sound "cp ~ cp*2 ~"
```

The structure comes from a *boolean* pattern, i.e. a binary one containing true or false values. Above we only used true values, denoted by `t`

. It's also possible to include false values with `f`

, which `struct`

will simply treat as silience. For example, this would have the same outcome as the above:

```
d1 $ struct ("t f t*2 f") $ sound "cp"
```

These true/false binary patterns become useful when you conditionally manipulate them, for example 'inverting' the values using every and inv:

```
d1 $ struct (every 3 inv "t f t*2 f") $ sound "cp"
```

In the above, the boolean values will be 'inverted' every third cycle, so that the structure comes from the `f`

s rather than `t`

.

Note that euclidean patterns also create true/false values, for example:

```
d1 $ struct (every 3 inv "t(3,8)") $ sound "cp"
```

In the above, the euclidean pattern creates `"t f t f t f f t"`

which gets inverted to `"f t f t f t t f"`

every third cycle.

Note that if you prefer you can use `1`

and `0`

instead of `t`

and `f`

.

See also mask.