# Union

---

```text
Union[CONTAINER | TRANSIENT] Collection[VAR_TREE_LIST; TYPE.SYMBOL]]
```

# Alias

```text
Tag[Collection[VAR_TREE_LIST; TYPE.SYMBOL]] `alias Union[[CONTAINER] Collection[VAR_TREE_LIST; TYPE.SYMBOL]]
```

## Tag Example

```text
u : Tag[I64.a; I64.b; I64.c] $ (.c : 5)

# u {
    .c {[c] c ... }
    { ... } // default
}
```

# Operators

## ``take`

# Transient Unions

Can only be retuned from functions and operations. The inner value must be moved out

## Alias

```text
Result[Generic.T] `alias Union[[TRANSIENT] Generic.T.value; Error.error]

Option[Generic.T] `alias Union[[TRANSIENT] Generic.T.some; Void.none]

Next[Generic.T] `alias Union[[TRANSIENT] Generic.T.iter; Void.done]

Next_result[Generic.T] `alias Union[[TRANSIENT] Generic.T.value; Error.error; Void.done]

Next_option[Generic.T] `alias Union[[TRANSIENT] Generic.T.some; Void.none; Void.done]
```

## Default Operation

When a transient union is assigned the first type specified is moved out.

If no match is used and if the type is not the first specified a result with an error is returned

```text
z : x / y // Result[...]
z // is value if y is not zero
```
## Operators

### \`value

### \`error

### \`some

### \`none