Struct rustful::context::Parameters

pub struct Parameters(_);

An extended HashMap with extra functionality for value parsing.

Some of the methods from HashMap has been wrapped to provide a more ergonomic API, where anything that can be represented as a byte slice can be used as a key.

Methods

impl Parameters

pub fn new() -> Parameters

Create an empty Parameters.

pub fn get<'a, K: ?Sized>(&'a self, key: &K) -> Option<Cow<'a, str>> where     K: Hash + Eq + AsRef<[u8]>,

Get a parameter as a UTF-8 string. A lossy conversion will be performed if it's not encoded as UTF-8. Use get_raw to get the original data.

pub fn get_raw<'a, K: ?Sized>(&'a self, key: &K) -> Option<&'a MaybeUtf8Owned> where     K: Hash + Eq + AsRef<[u8]>,

Get a parameter that may or may not be a UTF-8 string.

pub fn get_mut<'a, K: ?Sized>(     &'a mut self,     key: &K ) -> Option<&'a mut MaybeUtf8Owned> where     K: Hash + Eq + AsRef<[u8]>,

Get a mutable parameter that may or may not be a UTF-8 string.

pub fn contains_key<K: ?Sized>(&self, key: &K) -> bool where     K: Hash + Eq + AsRef<[u8]>,

Returns true if a parameter with the given key exists.

pub fn insert<K, V>(&mut self, key: K, value: V) -> Option<MaybeUtf8Owned> where     K: Into<MaybeUtf8Owned>,     V: Into<MaybeUtf8Owned>,

Insert a parameter.

pub fn remove<K: ?Sized>(&mut self, key: &K) -> Option<MaybeUtf8Owned> where     K: Hash + Eq + AsRef<[u8]>,

Remove a parameter and return it.

pub fn entry<K>(&mut self, key: K) -> Entry<MaybeUtf8Owned, MaybeUtf8Owned> where     K: Into<MaybeUtf8Owned>,

Gets the given key's corresponding parameter in the map for in-place manipulation.

pub fn parse<K: ?Sized, T>(&self, key: &K) -> Result<T, Option<T::Err>> where     K: Hash + Eq + AsRef<[u8]>,     T: FromStr,

Try to parse an entry as T, if it exists. The error will be None if the entry does not exist, and Some if it does exists, but the parsing failed.

fn my_handler(context: Context, response: Response) {
    let age: Result<u8, _> = context.variables.parse("age");
    match age {
        Ok(age) => response.send(format!("age: {}", age)),
        Err(Some(_)) => response.send("age must be a positive number"),
        Err(None) => response.send("no age provided")
    }
}

pub fn parse_or<K: ?Sized, T>(&self, key: &K, or: T) -> T where     K: Hash + Eq + AsRef<[u8]>,     T: FromStr,

Try to parse an entry as T, if it exists, or return the default in or.

fn my_handler(context: Context, response: Response) {
    let page = context.variables.parse_or("page", 0u8);
    response.send(format!("current page: {}", page));
}

pub fn parse_or_else<K: ?Sized, T, F>(&self, key: &K, or_else: F) -> T where     K: Hash + Eq + AsRef<[u8]>,     T: FromStr,     F: FnOnce(Option<T::Err>) -> T,

Try to parse an entry as T, if it exists, or create a new one using or_else. The or_else function will receive the parsing error if the value existed, but was impossible to parse.

fn my_handler(context: Context, response: Response) {
    let science = context.variables.parse_or_else("science", |_| do_heavy_stuff());
    response.send(format!("science value: {}", science));
}

Methods from Deref<Target = HashMap<MaybeUtf8Owned, MaybeUtf8Owned>>

Important traits for &'a mut R

impl<'a, R> Read for &'a mut R where
    R: Read + ?Sized, impl<'a, W> Write for &'a mut W where
    W: Write + ?Sized, impl<'a, I> Iterator for &'a mut I where
    I: Iterator + ?Sized,  type Item = <I as Iterator>::Item;

pub fn hasher(&self) -> &S

Returns a reference to the map's BuildHasher.

Examples

use std::collections::HashMap;
use std::collections::hash_map::RandomState;

let hasher = RandomState::new();
let map: HashMap<i32, i32> = HashMap::with_hasher(hasher);
let hasher: &RandomState = map.hasher();

pub fn capacity(&self) -> usize

Returns the number of elements the map can hold without reallocating.

This number is a lower bound; the HashMap<K, V> might be able to hold more, but is guaranteed to be able to hold at least this many.

Examples

use std::collections::HashMap;
let map: HashMap<i32, i32> = HashMap::with_capacity(100);
assert!(map.capacity() >= 100);

pub fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more elements to be inserted in the HashMap. The collection may reserve more space to avoid frequent reallocations.

Panics

Panics if the new allocation size overflows usize.

Examples

use std::collections::HashMap;
let mut map: HashMap<&str, i32> = HashMap::new();
map.reserve(10);

pub fn try_reserve(     &mut self,     additional: usize ) -> Result<(), CollectionAllocErr>

🔬 This is a nightly-only experimental API. (try_reserve)

new API

Tries to reserve capacity for at least additional more elements to be inserted in the given HashMap<K,V>. The collection may reserve more space to avoid frequent reallocations.

Errors

If the capacity overflows, or the allocator reports a failure, then an error is returned.

Examples

#![feature(try_reserve)]
use std::collections::HashMap;
let mut map: HashMap<&str, isize> = HashMap::new();
map.try_reserve(10).expect("why is the test harness OOMing on 10 bytes?");

pub fn shrink_to_fit(&mut self)

Shrinks the capacity of the map as much as possible. It will drop down as much as possible while maintaining the internal rules and possibly leaving some space in accordance with the resize policy.

Examples

use std::collections::HashMap;

let mut map: HashMap<i32, i32> = HashMap::with_capacity(100);
map.insert(1, 2);
map.insert(3, 4);
assert!(map.capacity() >= 100);
map.shrink_to_fit();
assert!(map.capacity() >= 2);

pub fn shrink_to(&mut self, min_capacity: usize)

🔬 This is a nightly-only experimental API. (shrink_to)

new API

Shrinks the capacity of the map with a lower limit. It will drop down no lower than the supplied limit while maintaining the internal rules and possibly leaving some space in accordance with the resize policy.

Panics if the current capacity is smaller than the supplied minimum capacity.

Examples

#![feature(shrink_to)]
use std::collections::HashMap;

let mut map: HashMap<i32, i32> = HashMap::with_capacity(100);
map.insert(1, 2);
map.insert(3, 4);
assert!(map.capacity() >= 100);
map.shrink_to(10);
assert!(map.capacity() >= 10);
map.shrink_to(0);
assert!(map.capacity() >= 2);

Important traits for Keys<'a, K, V>

impl<'a, K, V> Iterator for Keys<'a, K, V> type Item = &'a K;

pub fn keys(&self) -> Keys<K, V>

An iterator visiting all keys in arbitrary order. The iterator element type is &'a K.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

for key in map.keys() {
    println!("{}", key);
}

Important traits for Values<'a, K, V>

impl<'a, K, V> Iterator for Values<'a, K, V> type Item = &'a V;

pub fn values(&self) -> Values<K, V>

An iterator visiting all values in arbitrary order. The iterator element type is &'a V.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

for val in map.values() {
    println!("{}", val);
}

Important traits for ValuesMut<'a, K, V>

impl<'a, K, V> Iterator for ValuesMut<'a, K, V> type Item = &'a mut V;

pub fn values_mut(&mut self) -> ValuesMut<K, V>

An iterator visiting all values mutably in arbitrary order. The iterator element type is &'a mut V.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();

map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

for val in map.values_mut() {
    *val = *val + 10;
}

for val in map.values() {
    println!("{}", val);
}

Important traits for Iter<'a, K, V>

impl<'a, K, V> Iterator for Iter<'a, K, V> type Item = (&'a K, &'a V);

pub fn iter(&self) -> Iter<K, V>

An iterator visiting all key-value pairs in arbitrary order. The iterator element type is (&'a K, &'a V).

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

for (key, val) in map.iter() {
    println!("key: {} val: {}", key, val);
}

Important traits for IterMut<'a, K, V>

impl<'a, K, V> Iterator for IterMut<'a, K, V> type Item = (&'a K, &'a mut V);

pub fn iter_mut(&mut self) -> IterMut<K, V>

An iterator visiting all key-value pairs in arbitrary order, with mutable references to the values. The iterator element type is (&'a K, &'a mut V).

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert("a", 1);
map.insert("b", 2);
map.insert("c", 3);

// Update all values
for (_, val) in map.iter_mut() {
    *val *= 2;
}

for (key, val) in &map {
    println!("key: {} val: {}", key, val);
}

pub fn entry(&mut self, key: K) -> Entry<K, V>

Gets the given key's corresponding entry in the map for in-place manipulation.

Examples

use std::collections::HashMap;

let mut letters = HashMap::new();

for ch in "a short treatise on fungi".chars() {
    let counter = letters.entry(ch).or_insert(0);
    *counter += 1;
}

assert_eq!(letters[&'s'], 2);
assert_eq!(letters[&'t'], 3);
assert_eq!(letters[&'u'], 1);
assert_eq!(letters.get(&'y'), None);

pub fn len(&self) -> usize

Returns the number of elements in the map.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
assert_eq!(a.len(), 0);
a.insert(1, "a");
assert_eq!(a.len(), 1);

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
assert!(a.is_empty());
a.insert(1, "a");
assert!(!a.is_empty());

Important traits for Drain<'a, K, V>

impl<'a, K, V> Iterator for Drain<'a, K, V> type Item = (K, V);

pub fn drain(&mut self) -> Drain<K, V>

Clears the map, returning all key-value pairs as an iterator. Keeps the allocated memory for reuse.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
a.insert(1, "a");
a.insert(2, "b");

for (k, v) in a.drain().take(1) {
    assert!(k == 1 || k == 2);
    assert!(v == "a" || v == "b");
}

assert!(a.is_empty());

pub fn clear(&mut self)

Clears the map, removing all key-value pairs. Keeps the allocated memory for reuse.

Examples

use std::collections::HashMap;

let mut a = HashMap::new();
a.insert(1, "a");
a.clear();
assert!(a.is_empty());

pub fn get<Q>(&self, k: &Q) -> Option<&V> where     K: Borrow<Q>,     Q: Hash + Eq + ?Sized,

Returns a reference to the value corresponding to the key.

The key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.get(&1), Some(&"a"));
assert_eq!(map.get(&2), None);

pub fn get_key_value<Q>(&self, k: &Q) -> Option<(&K, &V)> where     K: Borrow<Q>,     Q: Hash + Eq + ?Sized,

🔬 This is a nightly-only experimental API. (map_get_key_value)

Returns the key-value pair corresponding to the supplied key.

The supplied key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

#![feature(map_get_key_value)]
use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.get_key_value(&1), Some((&1, &"a")));
assert_eq!(map.get_key_value(&2), None);

pub fn contains_key<Q>(&self, k: &Q) -> bool where     K: Borrow<Q>,     Q: Hash + Eq + ?Sized,

Returns true if the map contains a value for the specified key.

The key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.contains_key(&1), true);
assert_eq!(map.contains_key(&2), false);

pub fn get_mut<Q>(&mut self, k: &Q) -> Option<&mut V> where     K: Borrow<Q>,     Q: Hash + Eq + ?Sized,

Returns a mutable reference to the value corresponding to the key.

The key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
if let Some(x) = map.get_mut(&1) {
    *x = "b";
}
assert_eq!(map[&1], "b");

pub fn insert(&mut self, k: K, v: V) -> Option<V>

Inserts a key-value pair into the map.

If the map did not have this key present, None is returned.

If the map did have this key present, the value is updated, and the old value is returned. The key is not updated, though; this matters for types that can be == without being identical. See the module-level documentation for more.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
assert_eq!(map.insert(37, "a"), None);
assert_eq!(map.is_empty(), false);

map.insert(37, "b");
assert_eq!(map.insert(37, "c"), Some("b"));
assert_eq!(map[&37], "c");

pub fn remove<Q>(&mut self, k: &Q) -> Option<V> where     K: Borrow<Q>,     Q: Hash + Eq + ?Sized,

Removes a key from the map, returning the value at the key if the key was previously in the map.

The key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.remove(&1), Some("a"));
assert_eq!(map.remove(&1), None);

pub fn remove_entry<Q>(&mut self, k: &Q) -> Option<(K, V)> where     K: Borrow<Q>,     Q: Hash + Eq + ?Sized,

🔬 This is a nightly-only experimental API. (hash_map_remove_entry)

Removes a key from the map, returning the stored key and value if the key was previously in the map.

The key may be any borrowed form of the map's key type, but Hash and Eq on the borrowed form must match those for the key type.

Examples

#![feature(hash_map_remove_entry)]
use std::collections::HashMap;

let mut map = HashMap::new();
map.insert(1, "a");
assert_eq!(map.remove_entry(&1), Some((1, "a")));
assert_eq!(map.remove(&1), None);

pub fn retain<F>(&mut self, f: F) where     F: FnMut(&K, &mut V) -> bool,

Retains only the elements specified by the predicate.

In other words, remove all pairs (k, v) such that f(&k,&mut v) returns false.

Examples

use std::collections::HashMap;

let mut map: HashMap<i32, i32> = (0..8).map(|x|(x, x*10)).collect();
map.retain(|&k, _| k % 2 == 0);
assert_eq!(map.len(), 4);

Trait Implementations

impl Clone for Parameters

fn clone(&self) -> Parameters

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Deref for Parameters

type Target = HashMap<MaybeUtf8Owned, MaybeUtf8Owned>

The resulting type after dereferencing.

fn deref(&self) -> &HashMap<MaybeUtf8Owned, MaybeUtf8Owned>

Dereferences the value.

impl DerefMut for Parameters

fn deref_mut(&mut self) -> &mut HashMap<MaybeUtf8Owned, MaybeUtf8Owned>

Mutably dereferences the value.

impl AsRef<HashMap<MaybeUtf8Owned, MaybeUtf8Owned>> for Parameters

fn as_ref(&self) -> &HashMap<MaybeUtf8Owned, MaybeUtf8Owned>

Performs the conversion.

impl AsMut<HashMap<MaybeUtf8Owned, MaybeUtf8Owned>> for Parameters

fn as_mut(&mut self) -> &mut HashMap<MaybeUtf8Owned, MaybeUtf8Owned>

Performs the conversion.

impl Into<HashMap<MaybeUtf8Owned, MaybeUtf8Owned>> for Parameters

fn into(self) -> HashMap<MaybeUtf8Owned, MaybeUtf8Owned>

Performs the conversion.

impl From<HashMap<MaybeUtf8Owned, MaybeUtf8Owned>> for Parameters

fn from(map: HashMap<MaybeUtf8Owned, MaybeUtf8Owned>) -> Parameters

Performs the conversion.

impl PartialEq for Parameters

fn eq(&self, other: &Parameters) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl Eq for Parameters

impl Debug for Parameters

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

Formats the value using the given formatter.

impl Default for Parameters

fn default() -> Parameters

Returns the "default value" for a type.

impl IntoIterator for Parameters

type IntoIter = <HashMap<MaybeUtf8Owned, MaybeUtf8Owned> as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

type Item = (MaybeUtf8Owned, MaybeUtf8Owned)

The type of the elements being iterated over.

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a> IntoIterator for &'a Parameters

type IntoIter = <&'a HashMap<MaybeUtf8Owned, MaybeUtf8Owned> as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

type Item = (&'a MaybeUtf8Owned, &'a MaybeUtf8Owned)

The type of the elements being iterated over.

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a> IntoIterator for &'a mut Parameters

type IntoIter = <&'a mut HashMap<MaybeUtf8Owned, MaybeUtf8Owned> as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

type Item = (&'a MaybeUtf8Owned, &'a mut MaybeUtf8Owned)

The type of the elements being iterated over.

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<K: Into<MaybeUtf8Owned>, V: Into<MaybeUtf8Owned>> FromIterator<(K, V)> for Parameters

fn from_iter<T: IntoIterator<Item = (K, V)>>(iterable: T) -> Parameters

Creates a value from an iterator.

impl<K: Into<MaybeUtf8Owned>, V: Into<MaybeUtf8Owned>> Extend<(K, V)> for Parameters

fn extend<T: IntoIterator<Item = (K, V)>>(&mut self, iter: T)

Extends a collection with the contents of an iterator.