| Marcel van Lohuizen | e899250 | 2019-01-11 13:10:54 +0100 | [diff] [blame] | 1 | [TOC](Readme.md) [Prev](unification.md) [Next](defaults.md) |
| Marcel van Lohuizen | 75cb003 | 2019-01-11 12:10:48 +0100 | [diff] [blame] | 2 | |
| Marcel van Lohuizen | 3e592b4 | 2019-01-11 20:31:29 +0100 | [diff] [blame] | 3 | _Types ~~and~~ are Values_ |
| Marcel van Lohuizen | af0932f | 2019-01-11 13:03:56 +0100 | [diff] [blame] | 4 | |
| Marcel van Lohuizen | 75cb003 | 2019-01-11 12:10:48 +0100 | [diff] [blame] | 5 | # Disjunctions |
| 6 | |
| 7 | Disjunctions, or sum types, define a new type that is one of several things. |
| 8 | |
| 9 | In the example, `conn` defines a `protocol` field that must be one of two |
| Anthony Yeh | 1dda348 | 2019-02-13 14:10:43 -0800 | [diff] [blame] | 10 | values: `"tcp"` or `"udp"`. |
| Marcel van Lohuizen | 75cb003 | 2019-01-11 12:10:48 +0100 | [diff] [blame] | 11 | It is an error for a concrete `conn` |
| 12 | to define anything else than these two values. |
| 13 | |
| 14 | <!-- CUE editor --> |
| 15 | ``` |
| 16 | conn: { |
| 17 | address: string |
| 18 | port: int |
| 19 | protocol: "tcp" | "udp" |
| 20 | } |
| 21 | |
| Anthony Yeh | 1dda348 | 2019-02-13 14:10:43 -0800 | [diff] [blame] | 22 | lossy: conn & { |
| Marcel van Lohuizen | 75cb003 | 2019-01-11 12:10:48 +0100 | [diff] [blame] | 23 | address: "1.2.3.4" |
| 24 | port: 8888 |
| 25 | protocol: "udp" |
| 26 | } |
| Anthony Yeh | 1dda348 | 2019-02-13 14:10:43 -0800 | [diff] [blame] | 27 | ``` |
