Struct Context 

pub struct Context { /* private fields */ }

The primary representation of a CCS search state

Typically you’ll want the Context::logging constructor, or (if not using the log feature), the Context::load_with_tracer. See PropertyTracer for more information.

In tests, you may want Context::from_str with test implementations of resolvers and tracers.

Implementations

impl Context

pub fn logging(path: impl AsRef<Path>, level: Level) -> CcsResult<Self>

Loads a CCS file, and creates a context that logs when and where properties are found

Uses the RelativePathResolver

See PropertyTracer and LogTracer for more.

impl Context

pub fn from_str_without_tracing(ccs: impl AsRef<str>) -> AstResult<Self>

Creates a context that does not trace when or where properties are found

Will use an empty ImportResolver, that just skips over import statements. To provide a different ImportResolver, use Context::from_str

Generally this is most useful in tests.

impl Context

pub fn load_with_tracer( path: impl AsRef<Path>, tracer: impl PropertyTracer + 'static, ) -> CcsResult<Self>

Loads a CCS file, and creates a context with the provided tracer

Uses the RelativePathResolver

See PropertyTracer for more.

pub fn load( path: impl AsRef<Path>, resolver: impl ImportResolver, tracer: impl PropertyTracer + 'static, ) -> CcsResult<Self>

Loads a CCS file, and creates a context with the provided import resolver and tracer

See ImportResolver PropertyTracer for more.

pub fn from_str( ccs: impl AsRef<str>, resolver: impl ImportResolver, tracer: impl PropertyTracer + 'static, ) -> AstResult<Self>

Creates a context from a provided CCS string, using the provided import resolver and tracer

See ImportResolver PropertyTracer for more.

Mostly useful for tests.

pub fn constrain(&self, constraint: impl AsKey) -> Self

Create a new context augmented with the given constraint

Example: Key-only constraint

Given the following CCS:

module : a = z

the property a can be retrieved through constraining with "module":

assert!(context.get_value("a").is_err());

let x: &str = &context.constrain("module").get_value("a")?;
assert_eq!(x, "z");

Example: Key-value constraint

Given the following CCS;

env.prod : a = z

the property a can be retrieved through constraining with ("env", "prod"):

assert!(context.constrain("env").get_value("a").is_err());

let x: &str = &context.constrain(("env", "prod")).get_value("a")?;
assert_eq!(x, "z");

pub fn get(&self, prop: impl AsRef<str>) -> SearchResult<PropertyValue>

Retrieves the value of a property from the current context, if possible

pub fn get_value(&self, prop: impl AsRef<str>) -> SearchResult<PersistentStr>

Helper function for Context::get to get PropertyValue::value

pub fn get_type<T: TypedProperty>( &self, prop: impl AsRef<str>, ) -> ContextResult<T>

Helper for the ever-common “get and convert” pattern

context.get_type::<T>(prop) is basically equivalent to context.get(prop)?.to_type::<T>()

assert_eq!(context.get_type::<i32>("x")?, 42);

pub fn get_or<T: TypedProperty>(&self, prop: impl AsRef<str>, default: T) -> T

Get a typed value, or provide the default if it cannot be found

assert_eq!(&context.get_or("undefined", "default_val".to_string()), "default_val");

pub fn get_or_default<T: TypedProperty + Default>( &self, prop: impl AsRef<str>, ) -> T

Get a typed value, or return the type’s Default value

assert_eq!(&context.get_or_default::<String>("undefined"), "");

pub fn get_current_context(&self) -> DisplayContext

Retrieves the current context’s queue of applied constraints, in the order they were applied

pub fn get_dag_stats(&self) -> DagStats

Retrieves information about the DAG that underpins the activation algorithm

pub fn dag_as_dot_str(&self) -> String

Turns the underlying DAG into a DOT string, which can be used for visualization.

Requires the dot feature

Trait Implementations

impl Clone for Context

fn clone(&self) -> Context

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.