# bacnet-types
BACnet identifiers, enum values, addresses, property values and errors for the
[Rusty BACnet](https://github.com/jscott3201/rusty-bacnet) workspace.
These are protocol data types; this crate does not open a transport or run a device.
## Quickstart from development source
The dependency blocks below use a checkout named `rusty-bacnet` beside your
application directory. They describe the development source, not the contents
of a published crate version. Adjust the relative path for another layout.
```toml
[dependencies]
bacnet-types = { path = "../rusty-bacnet/crates/bacnet-types" }
```
Construct an identifier for a concrete object, check its wire bytes, and decode
it again. `new_addressable` rejects the wildcard instance as well as values
outside the field widths; `new` and `decode` also support the valid wire wildcard.
```rust
use bacnet_types::enums::ObjectType;
use bacnet_types::primitives::ObjectIdentifier;
fn main() -> Result<(), bacnet_types::error::Error> {
let object = ObjectIdentifier::new_addressable(ObjectType::ANALOG_INPUT, 7)?;
let wire = object.encode();
assert_eq!(wire, [0x00, 0x00, 0x00, 0x07]);
assert_eq!(ObjectIdentifier::decode(&wire)?, object);
assert_eq!(object.instance_number(), 7);
assert!(ObjectIdentifier::new(
ObjectType::DEVICE,
ObjectIdentifier::MAX_INSTANCE + 1,
).is_err());
Ok(())
}
```
## Features and allocation
The crate has three profiles. With neither `std` nor `alloc` it builds without
an allocator (#1614), for firmware with no heap.
| Hosted | `std` (default) | Everything, including `error::Error::Transport`. Enables `alloc`. |
| `no_std` with a heap | `alloc` | Everything but `Error::Transport`. Firmware must supply a global allocator. `bip_port` needs atomic compare-and-swap too, so ARMv6-M goes without it (#1615). |
| No allocator | neither | The enums, `ObjectIdentifier`, `Date`, `Time`, `BACnetTimeStamp`, the bit-string flag types, the `text` table of hidden characters and the error type. The owned values (`PropertyValue`, the `constructed` types, `MacAddr`, the `calendar` matching) need `alloc`. |
| | `serde` | Deserialization for `enums::ObjectType` and `enums::PropertyIdentifier`; enables `alloc`, without selecting `std`. |
Without `alloc`, `error::Error` keeps only the variants that own nothing. A
decoder's refusal is `Error::Decoding(DecodeError)`, an encoder's
`Error::Encode(EncodeError)`, a checked constructor's `Error::Range(RangeError)`
and a segmenter's `Error::Segmentation(SegmentationError)`: each carries static
labels or numbers and builds its text only when it is displayed (#1646, #1802),
so firmware that never displays one links no formatting for it. Every decoder
and every codec-crate encoder reports these forms (#1776, #1802). With `alloc`,
the owned `Error::Encoding`, `Error::OutOfRange` and `Error::Structured` return.
Enum newtypes support `FromStr` for their named constants in common case styles,
such as `analog-input` and `ANALOG_INPUT`. The normal runtime dependencies are
`bacnet-npdu`, `bitflags` and `thiserror`, plus `smallvec` with `alloc` and `serde` when
selected.
For an alloc-only dependency build, replace the dependency block with:
```toml
[dependencies]
bacnet-types = { path = "../rusty-bacnet/crates/bacnet-types", default-features = false, features = ["alloc"] }
```
For a build without an allocator, leave out `features = ["alloc"]`. The
quickstart runs on a host with any of the three blocks; CI also builds each
profile for ARMv6-M, ARMv7E-M and RISC-V (`scripts/ci/check-no-std.sh`), which
shows the code needs no `std`, and no heap without `alloc`, but doesn't run it
there. A firmware application supplies its runtime, and with `alloc` its
allocator. Cargo features are additive: another dependency can enable `alloc`
or `std` again, so inspect the application's resolved feature graph.
## API documentation
This README is also the crate's Rust documentation landing page. The docs.rs
profile explicitly enables `std` and `serde`, disables implicit defaults, and
renders only the default `x86_64-unknown-linux-gnu` target. Documented items
follow their real feature gates; this profile does not establish firmware
qualification. The library's module pages describe the individual types.