Crate rocket_codegen [−] [src]
Rocket - Code Generation
This crate implements the code generation portions of Rocket. This includes custom derives, custom attributes, procedural macros, and lints. The documentation here is purely technical. The code generation facilities are documented thoroughly in the Rocket programming guide.
Custom Attributes
This crate implements the following custom attributes:
- route
- get
- put
- post
- delete
- head
- patch
- options
- error
The grammar for all route attributes, including route, get, put, post, delete, head, patch, and options is defined as:
route := METHOD? '(' ('path' '=')? path (',' kv_param)* ')' path := URI_SEG | DYNAMIC_PARAM | '?' DYNAMIC_PARAM | path '/' path (string literal) kv_param := 'rank' '=' INTEGER | 'format' '=' STRING | 'data' '=' DYNAMIC_PARAM INTEGER := isize, as defined by Rust STRING := UTF-8 string literal, as defined by Rust IDENT := Valid identifier, as defined by Rust URI_SEG := Valid HTTP URI Segment DYNAMIC_PARAM := '<' IDENT '..'? '>' (string literal)
Note that the route attribute takes a method as its first argument, while the remaining do not. That is, route looks like:
#[route(GET, path = "/hello")]
while the equivalent using get looks like:
#[get("/hello")]
The syntax for the error attribute is:
error := INTEGER
A use of the error
attribute looks like:
#[error(404)]
Custom Derives
This crate implements the following custom derives:
- FromForm
Procedural Macros
This crate implements the following procedural macros:
- routes
- errors
The syntax for both of these is defined as:
macro := PATH (',' macro)* PATH := a path, as defined by Rust
Lints
This crate implements the following lints:
unmounted_route: defaults to warn
emits a warning when a declared route is not mounted
unmanaged_state: defaults to warn
emits a warning when a
State<T>
request guest is used in a mounted route without managing a value forT
Debugging Codegen
When the ROCKET_CODEGEN_DEBUG
environment variable is set, this crate logs
the items it has generated to the console at compile-time. For example, you
might run the following to build a Rocket application with codegen logging
enabled:
ROCKET_CODEGEN_DEBUG=1 cargo build
Functions
plugin_registrar |
Compiler hook for Rust to register plugins. |