# Diagrams/Dev/Migrate1.1

From HaskellWiki

This page describes breaking API changes between diagrams 1.0 and 1.1, along with explanations of how to migrate to the new 1.1 API.

## Angles are now represented by a single type

The types `Turn`

, `Rad`

, and `Deg`

have been subsumed by the new type `Angle`

. The old type class `Angle`

is no longer needed. See the user manual for more exposition.

Code which constructed angles like

```
(0.5 :: Turn)
```

can be written instead as

```
(0.5 @@ turn)
```

The new functions `rad`

and `deg`

can be used similarly. All three have type Iso from `lens`

.

Extracting a measurement with particular units, which used to look like

```
Rad theta = convertAngle a
```

can be written

```
theta = a ^. rad
```

The function `convertAngle`

is no longer needed, and has been removed. Finally, where the `Angle`

type class was used as a constraint,

```
Angle a => a -> b
```

becomes

```
Angle -> b
```