Struct SimpleContext

pub struct SimpleContext { /* private fields */ }

Available on crate feature alloc only.

Simple template expansion context.

Implementations

impl SimpleContext

pub fn new() -> Self

Creates a new empty context.

Examples

use iri_string::spec::UriSpec;
use iri_string::template::UriTemplateStr;
use iri_string::template::simple_context::SimpleContext;

let empty_ctx = SimpleContext::new();
let template = UriTemplateStr::new("{no_such_variable}")?;
let expanded = template.expand::<UriSpec, _>(&empty_ctx)?;

assert_eq!(
    expanded.to_string(),
    ""
);

pub fn insert<K, V>(&mut self, key: K, value: V) -> Option<Value>

where K: Into<String>, V: Into<Value>,

Inserts a variable.

Passing Value::Undefined removes the value from the context.

The entry will be inserted or removed even if the key is invalid as a variable name. Such entries will be simply ignored on expansion.

Examples

use iri_string::spec::UriSpec;
use iri_string::template::UriTemplateStr;
use iri_string::template::simple_context::SimpleContext;

let mut context = SimpleContext::new();
context.insert("username", "foo");

let template = UriTemplateStr::new("/users/{username}")?;
let expanded = template.expand::<UriSpec, _>(&context)?;

assert_eq!(
    expanded.to_string(),
    "/users/foo"
);

Passing Value::Undefined removes the value from the context.

# [cfg(feature = "alloc")] {
use iri_string::spec::UriSpec;
use iri_string::template::UriTemplateStr;
use iri_string::template::simple_context::{SimpleContext, Value};

let mut context = SimpleContext::new();
context.insert("username", "foo");
context.insert("username", Value::Undefined);

let template = UriTemplateStr::new("/users/{username}")?;
let expanded = template.expand::<UriSpec, _>(&context)?;

assert_eq!(
    expanded.to_string(),
    "/users/"
);

pub fn clear(&mut self)

Removes all entries in the context.

Examples

use iri_string::spec::UriSpec;
use iri_string::template::UriTemplateStr;
use iri_string::template::simple_context::SimpleContext;

let template = UriTemplateStr::new("{foo,bar}")?;
let mut context = SimpleContext::new();

context.insert("foo", "FOO");
context.insert("bar", "BAR");
assert_eq!(
    template.expand::<UriSpec, _>(&context)?.to_string(),
    "FOO,BAR"
);

context.clear();
assert_eq!(
    template.expand::<UriSpec, _>(&context)?.to_string(),
    ""
);

pub fn get(&self, key: VarName<'_>) -> Option<&Value>

Returns a reference to the value for the key.

Trait Implementations

impl Clone for SimpleContext

fn clone(&self) -> SimpleContext

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Context for SimpleContext

fn visit<V: Visitor>(&self, visitor: V) -> V::Result

Visits a variable.

impl Debug for SimpleContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for SimpleContext

fn default() -> SimpleContext

Returns the “default value” for a type.