### Rust String Pattern Matching Examples

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/str/pattern/index

Demonstrates various ways to use the `Pattern` trait for searching within strings in Rust. It shows examples using string slices, characters, character arrays, and closures as patterns. This API is currently experimental but exposed via stable `str` methods.

```rust
let s = "Can you find a needle in a haystack?";

// &str pattern
assert_eq!(s.find("you"), Some(4));
// char pattern
assert_eq!(s.find('n'), Some(2));
// array of chars pattern
assert_eq!(s.find(&['a', 'e', 'i', 'o', 'u']), Some(1));
// slice of chars pattern
assert_eq!(s.find(&['a', 'e', 'i', 'o', 'u'][..]), Some(1));
// closure pattern
assert_eq!(s.find(|c: char| c.is_ascii_punctuation()), Some(35));
```

--------------------------------

### Rust Result expect() Example for Panic and Recommended Usage

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/type

Illustrates the `expect()` method for retrieving the Ok value or panicking with a custom message if the Result is Err. Includes examples of both panicking behavior and recommended usage for clarity in error reporting.

```Rust
let x: Result<u32, &str> = Err("emergency failure");
x.expect("Testing expect"); // panics with `Testing expect: emergency failure`
```

```Rust
let path = std::env::var("IMPORTANT_PATH")
    .expect("env variable `IMPORTANT_PATH` should be set by `wrapper_script.sh`");
```

--------------------------------

### Dijkstra's Shortest Path Algorithm with BinaryHeap in Rust

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/binary_heap/index

Implements Dijkstra's shortest path algorithm using Rust's `BinaryHeap` as a min-priority queue. It defines a `State` struct to hold cost and position, implementing `Ord` and `PartialOrd` for min-heap behavior. The `shortest_path` function takes an adjacency list, start, and goal node, returning the shortest distance or `None` if unreachable. It includes a `main` function with a sample graph and assertions.

```rust
use std::cmp::Ordering;
use std::collections::BinaryHeap;

#[derive(Copy, Clone, Eq, PartialEq)]
struct State {
    cost: usize,
    position: usize,
}

// The priority queue depends on `Ord`.
// Explicitly implement the trait so the queue becomes a min-heap
// instead of a max-heap.
impl Ord for State {
    fn cmp(&self, other: &Self) -> Ordering {
        // Notice that we flip the ordering on costs.
        // In case of a tie we compare positions - this step is necessary
        // to make implementations of `PartialEq` and `Ord` consistent.
        other.cost.cmp(&self.cost)
            .then_with(|| self.position.cmp(&other.position))
    }
}

// `PartialOrd` needs to be implemented as well.
impl PartialOrd for State {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

// Each node is represented as a `usize`, for a shorter implementation.
struct Edge {
    node: usize,
    cost: usize,
}

// Dijkstra's shortest path algorithm.

// Start at `start` and use `dist` to track the current shortest distance
// to each node. This implementation isn't memory-efficient as it may leave duplicate
// nodes in the queue. It also uses `usize::MAX` as a sentinel value,
// for a simpler implementation.
fn shortest_path(adj_list: &Vec<Vec<Edge>>, start: usize, goal: usize) -> Option<usize> {
    // dist[node] = current shortest distance from `start` to `node`
    let mut dist: Vec<_> = (0..adj_list.len()).map(|_| usize::MAX).collect();

    let mut heap = BinaryHeap::new();

    // We're at `start`, with a zero cost
    dist[start] = 0;
    heap.push(State { cost: 0, position: start });

    // Examine the frontier with lower cost nodes first (min-heap)
    while let Some(State { cost, position }) = heap.pop() {
        // Alternatively we could have continued to find all shortest paths
        if position == goal { return Some(cost); }

        // Important as we may have already found a better way
        if cost > dist[position] { continue; }

        // For each node we can reach, see if we can find a way with
        // a lower cost going through this node
        for edge in &adj_list[position] {
            let next = State { cost: cost + edge.cost, position: edge.node };

            // If so, add it to the frontier and continue
            if next.cost < dist[next.position] {
                heap.push(next);
                // Relaxation, we have now found a better way
                dist[next.position] = next.cost;
            }
        }
    }

    // Goal not reachable
    None
}

fn main() {
    // This is the directed graph we're going to use.
    // The node numbers correspond to the different states,
    // and the edge weights symbolize the cost of moving
    // from one node to another.
    // Note that the edges are one-way.
    //
    //                  7
    //          +-----------------+
    //          |                 |
    //          v   1        2    |  2
    //          0 -----> 1 -----> 3 ---> 4
    //          |        ^        ^      ^
    //          |        | 1      |      |
    //          |        |        | 3    | 1
    //          +------> 2 -------+      |
    //           10      |               |
    //                   +---------------+
    //
    // The graph is represented as an adjacency list where each index,
    // corresponding to a node value, has a list of outgoing edges.
    // Chosen for its efficiency.
    let graph = vec![
        // Node 0
        vec![Edge { node: 2, cost: 10 },
             Edge { node: 1, cost: 1 }],
        // Node 1
        vec![Edge { node: 3, cost: 2 }],
        // Node 2
        vec![Edge { node: 1, cost: 1 },
             Edge { node: 3, cost: 3 },
             Edge { node: 4, cost: 1 }],
        // Node 3
        vec![Edge { node: 0, cost: 7 },
             Edge { node: 4, cost: 2 }],
        // Node 4
        vec![]];

    assert_eq!(shortest_path(&graph, 0, 1), Some(1));
    assert_eq!(shortest_path(&graph, 0, 3), Some(3));
    assert_eq!(shortest_path(&graph, 3, 0), Some(7));
    assert_eq!(shortest_path(&graph, 0, 4), Some(5));
    assert_eq!(shortest_path(&graph, 4, 0), None);
}

```

--------------------------------

### Get URL Path in Rust

Source: https://docs.rs/starknet/latest/starknet/providers/struct

Retrieves the path component of a URL as a percent-encoded ASCII string. Handles different URL types, including those that cannot be a base. The path always starts with a '/' for valid base URLs.

```rust
use url::{Url, ParseError};

let url = Url::parse("https://example.com/api/versions?page=2")?;
assert_eq!(url.path(), "/api/versions");

let url = Url::parse("https://example.com")?;
assert_eq!(url.path(), "/");

let url = Url::parse("https://example.com/countries/việt nam")?;
assert_eq!(url.path(), "/countries/vi%E1%BB%87t%20nam");
```

--------------------------------

### Rust Result unwrap() Example for Ok and Err

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/type

Demonstrates the `unwrap()` method to get the Ok value or panic if the Result is Err. This method is generally discouraged in favor of safer error handling patterns like pattern matching or `unwrap_or` variants.

```Rust
let x: Result<u32, &str> = Ok(2);
assert_eq!(x.unwrap(), 2);
```

```Rust
let x: Result<u32, &str> = Err("emergency failure");
x.unwrap(); // panics with `emergency failure`
```

--------------------------------

### Example Usage of fmt::Error in Rust

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/struct

Demonstrates how to handle potential formatting errors using `std::fmt::write`. The example shows initializing an output string and using an `if let Err` pattern to catch and panic if the `write` operation returns a `fmt::Error`, indicating a failure in formatting the message into the string.

```rust
use std::fmt::{self, write};

let mut output = String::new();
if let Err(fmt::Error) = write(&mut output, format_args!("Hello {}!", "world")) {
    panic!("An error occurred");
}
```

--------------------------------

### Rust VecDeque Resize Example

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/struct

Demonstrates the resize method for VecDeque, showing how to truncate the deque or extend it by appending copies of a given value.

```rust
use std::collections::VecDeque;

let mut buf = VecDeque::new();
buf.push_back(5);
buf.push_back(10);
buf.push_back(15);
assert_eq!(buf, [5, 10, 15]);

buf.resize(2, 0);
assert_eq!(buf, [5, 10]);

buf.resize(5, 20);
assert_eq!(buf, [5, 10, 20, 20, 20]);
```

--------------------------------

### VecDeque Rotation Example

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/struct

Demonstrates the usage of the `rotate_right` method on a VecDeque.

```APIDOC
## VecDeque Rotation

### Description
Demonstrates how to rotate elements within a `VecDeque` to the right.

### Method
`rotate_right(mid: usize)`

### Endpoint
N/A (In-memory data structure)

### Parameters
#### Path Parameters
None

#### Query Parameters
None

#### Request Body
None

### Request Example
```rust
use std::collections::VecDeque;

let mut buf: VecDeque<_> = (0..10).collect();
buf.rotate_right(3);
assert_eq!(buf, [7, 8, 9, 0, 1, 2, 3, 4, 5, 6]);

for i in 1..10 {
    assert_eq!(0, buf[i * 3 % 10]);
    buf.rotate_right(3);
}
assert_eq!(buf, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
```

### Response
#### Success Response (200)
N/A (In-memory operation)

#### Response Example
N/A
```

--------------------------------

### Get Element by Index in VecDeque (Rust)

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/struct

Provides an example of accessing an element at a specific index in a VecDeque using the `get` method. It returns an `Option` which is `Some` if the index is valid, and `None` otherwise.

```rust
use std::collections::VecDeque;

let mut buf = VecDeque::new();
buf.push_back(3);
buf.push_back(4);
buf.push_back(5);
buf.push_back(6);
assert_eq!(buf.get(1), Some(&4));
```

--------------------------------

### SingleOwnerAccount Initialization and Configuration

Source: https://docs.rs/starknet/latest/starknet/accounts/struct

Details on how to create and configure a SingleOwnerAccount instance, including setting the provider, signer, address, chain ID, and execution encoding.

```APIDOC
## POST /accounts/singleowner

### Description
Creates a new `SingleOwnerAccount` controlled by a single signer. This account type is designed for Starknet contracts with a single ECDSA signer on the STARK curve.

### Method
POST

### Endpoint
`/accounts/singleowner`

### Parameters
#### Request Body
- **provider** (Provider) - Required - A `Provider` implementation that provides access to the Starknet network.
- **signer** (Signer) - Required - A `Signer` implementation that can generate valid signatures for this account.
- **address** (Felt) - Required - Account contract address.
- **chain_id** (Felt) - Required - Network chain ID.
- **encoding** (ExecutionEncoding) - Required - How `__execute__` calldata should be encoded.

### Request Example
```json
{
  "provider": "<Provider implementation>",
  "signer": "<Signer implementation>",
  "address": "0x12345...",
  "chain_id": "0x1",
  "encoding": "ExecutionEncoding::V1"
}
```

### Response
#### Success Response (200)
- **account** (SingleOwnerAccount) - The newly created `SingleOwnerAccount` instance.

#### Response Example
```json
{
  "account": "<SingleOwnerAccount instance>"
}
```

## PUT /accounts/singleowner/{address}/block_id

### Description
Sets a new block ID for the `SingleOwnerAccount`. This block ID will be used for subsequent queries and fee estimations.

### Method
PUT

### Endpoint
`/accounts/singleowner/{address}/block_id`

### Parameters
#### Path Parameters
- **address** (Felt) - Required - The address of the account.

#### Request Body
- **block_id** (BlockId) - Required - The new block ID to set.

### Request Example
```json
{
  "block_id": "latest"
}
```

### Response
#### Success Response (200)
- **message** (string) - Confirmation that the block ID has been updated.

#### Response Example
```json
{
  "message": "Block ID updated successfully."
}
```
```

--------------------------------

### Rust format! Macro Examples

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/index

Demonstrates various ways to use the `format!` macro in Rust for string interpolation and formatting. It covers basic string output, variable insertion, debugging output, named parameters, and advanced formatting like zero-padding and pretty-printing.

```Rust
format!("Hello");                 // => "Hello"
format!("Hello, {}!", "world");   // => "Hello, world!"
format!("The number is {}", 1);   // => "The number is 1"
format!("{:?}", (3, 4));          // => "(3, 4)"
format!("{value}", value=4);      // => "4"
let people = "Rustaceans";
format!("Hello {people}!");       // => "Hello Rustaceans!"
format!("{} {}", 1, 2);           // => "1 2"
format!("{:04}", 42);             // => "0042" with leading zeros
format!("{:#?}", (100, 200));     // => "(
                                  //       100,
                                  //       200,
                                  //     )"
```

--------------------------------

### Rust Result iter() Example

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/type

Demonstrates using the `iter()` method on a Result to get an iterator over the contained value. This is useful for iterating when the Result is Ok, and getting an empty iterator when it's Err.

```Rust
let x: Result<u32, &str> = Ok(7);
assert_eq!(x.iter().next(), Some(&7));

let x: Result<u32, &str> = Err("nothing!");
assert_eq!(x.iter().next(), None);
```

--------------------------------

### Rust Basic Formatting with Parameters

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/index

Demonstrates basic formatting parameters like 'e' for exponent and 'p' for pointer addresses in Rust's print macros. It shows how to apply these format specifiers to variables.

```rust
let a = 5;
let b = &a;
println!("{a:e} {b:p}"); // => 5e0 0x7ffe37b7273c
```

--------------------------------

### Rust Result iter_mut() Example

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/type

Shows how to use `iter_mut()` to get a mutable iterator for modifying the contained value if the Result is Ok. This allows in-place mutation of the Ok value.

```Rust
let mut x: Result<u32, &str> = Ok(7);
match x.iter_mut().next() {
    Some(v) => *v = 40,
    None => {},
}
assert_eq!(x, Ok(40));

let mut x: Result<u32, &str> = Err("nothing!");
assert_eq!(x.iter_mut().next(), None);
```

--------------------------------

### Create Empty LinkedList - Rust

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/linked_list/struct

Shows how to create a new, empty `LinkedList`. This is the standard way to start building a list when the elements are not known beforehand.

```Rust
use std::collections::LinkedList;

let list: LinkedList<u32> = LinkedList::new();
```

--------------------------------

### Peek Mutable Reference - Rust Vec Example

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/bstr/struct

Demonstrates the use of peek_mut() on a Vec<u8> (and by extension, ByteString) to get a mutable reference to the last element. This is a nightly-only experimental API.

```rust
#![feature(vec_peek_mut)]
let mut vec = Vec::new();
assert!(vec.peek_mut().is_none());

vec.push(1);
vec.push(5);
vec.push(2);
assert_eq!(vec.last(), Some(&2));
if let Some(mut val) = vec.peek_mut() {
    *val = 0;
}
assert_eq!(vec.last(), Some(&0));
```

--------------------------------

### Rust format! Named Parameters Examples

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/index

Shows the usage of named parameters in Rust's `format!` macro, including direct assignment and referencing variables from the current scope. It also demonstrates how to use named parameters when defining function return strings.

```Rust
format!("{argument}", argument = "test");   // => "test"
format!("{name} {}", 1, name = 2);          // => "2 1"
format!("{a} {c} {b}", a="a", b='b', c=3);  // => "a 3 b"
let argument = 2 + 2;
format!("{argument}");   // => "4"

fn make_string(a: u32, b: &str) -> String {
    format!("{b} {a}")
}
make_string(927, "label"); // => "label 927"
```

--------------------------------

### LocalWallet Methods

Source: https://docs.rs/starknet/latest/starknet/signers/struct

Methods available for constructing and interacting with LocalWallet.

```APIDOC
## LocalWallet Methods

### `from_signing_key`

#### Description
Constructs `LocalWallet` from a `SigningKey`.

#### Method
`pub fn from_signing_key(key: SigningKey) -> LocalWallet`

#### Parameters
- **key** (SigningKey) - Required - The signing key to initialize the wallet with.

#### Return Value
A new `LocalWallet` instance.

### `from<SigningKey>`

#### Description
Converts a `SigningKey` into a `LocalWallet`.

#### Method
`impl From<SigningKey> for LocalWallet`

#### Parameters
- **value** (SigningKey) - Required - The signing key to convert.

#### Return Value
A new `LocalWallet` instance.

### `sign_hash`

#### Description
Requests an ECDSA signature for a message hash.

#### Method
`async fn sign_hash<'life0, 'life1, 'async_trait>( &'life0 self, hash: &'life1 Felt, ) -> Result<Signature, SignError>`

#### Parameters
- **self** (&'life0 LocalWallet) - Required - The wallet instance.
- **hash** (&'life1 Felt) - Required - The hash of the message to sign.

#### Return Value
A `Result` containing the `Signature` on success, or a `SignError` on failure.

### `get_public_key`

#### Description
Retrieves the verifying (public) key from the signer.

#### Method
`async fn get_public_key<'life0, 'async_trait>( &'life0 self, ) -> Result<VerifyingKey, Infallible>`

#### Parameters
- **self** (&'life0 LocalWallet) - Required - The wallet instance.

#### Return Value
A `Result` containing the `VerifyingKey` on success. `Infallible` indicates this operation is guaranteed not to fail.

### `is_interactive`

#### Description
Indicates whether the underlying signer implementation is interactive.

#### Method
`fn is_interactive(&self, _context: SignerInteractivityContext<'_>) -> bool`

#### Parameters
- **self** (&self) - Required - The wallet instance.
- **_context** (SignerInteractivityContext<'_>) - Required - Context for interactivity (unused in this implementation).

#### Return Value
`false` as `LocalWallet` is not interactive.
```

--------------------------------

### Pattern Implementations

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/str/pattern/trait

Details on how specific types implement the Pattern trait, including examples and their associated Searcher types.

```APIDOC
## Implementors

### impl Pattern for char
Searches for chars that are equal to a given `char`.

#### §Examples
```rust
assert_eq!("Hello world".find('o'), Some(4));
```

#### type Searcher<'a> = CharSearcher<'a>

### impl<'b> Pattern for &'b str
Non-allocating substring search. Will handle the pattern `""` as returning empty matches at each character boundary.

#### §Examples
```rust
assert_eq!("Hello world".find("world"), Some(6));
```

#### type Searcher<'a> = StrSearcher<'a, 'b>

### impl<'b> Pattern for &'b String
A convenience impl that delegates to the impl for `&str`.

#### §Examples
```rust
assert_eq!(String::from("Hello world").find("world"), Some(6));
```
```

--------------------------------

### Rust Slice rchunks Example

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/bstr/struct

Demonstrates the `rchunks` method which returns an iterator over mutable chunks of a slice, starting from the end. The last chunk may be smaller if the slice length is not divisible by the chunk size. Panics if chunk_size is zero.

```rust
let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.rchunks(2);
assert_eq!(iter.next().unwrap(), &['e', 'm']);
assert_eq!(iter.next().unwrap(), &['o', 'r']);
assert_eq!(iter.next().unwrap(), &['l']);
assert!(iter.next().is_none());
```

--------------------------------

### Rust: H160 Constant Methods for Initialization

Source: https://docs.rs/starknet/latest/starknet/providers/sequencer/models/type

These H160 methods provide constant ways to create new H160 instances. `repeat_byte` fills the hash with a specified byte, `zero` creates a hash of all zeros, and `len_bytes` returns the fixed size of the hash in bytes. These are useful for setting default or specific initial states.

```rust
pub const fn repeat_byte(byte: u8) -> H160;
pub const fn zero() -> H160;
pub const fn len_bytes() -> usize;
```

--------------------------------

### Create Empty VecDeque (Rust)

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/struct

Shows how to create an empty VecDeque using the `new` function. This is the most basic way to start with an empty double-ended queue.

```rust
use std::collections::VecDeque;

let deque: VecDeque<u32> = VecDeque::new();
```

--------------------------------

### Construct LocalWallet from SigningKey (Rust)

Source: https://docs.rs/starknet/latest/starknet/signers/local_wallet/struct

Provides a constructor for the LocalWallet, allowing its creation directly from a SigningKey. This is a common way to initialize a LocalWallet instance.

```rust
pub fn from_signing_key(key: SigningKey) -> LocalWallet
```

--------------------------------

### Rust: Get element offset in a slice using element_offset

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/bstr/struct

Illustrates the `element_offset` method, which returns the byte index of an element reference within a slice. This nightly-only API is useful for extending slice iterators and works via pointer arithmetic, not element comparison. It returns `None` if the element is not at the start of another element within the slice.

```rust
#![feature(substr_range)]

let nums: &[u32] = &[1, 7, 1, 1];
let num = &nums[2];

assert_eq!(num, &1);
assert_eq!(nums.element_offset(num), Some(2));
```

```rust
#![feature(substr_range)]

let arr: &[[u32; 2]] = &[[0, 1], [2, 3]];
let flat_arr: &[u32] = arr.as_flattened();

let ok_elm: &[u32; 2] = flat_arr[0..2].try_into().unwrap();
let weird_elm: &[u32; 2] = flat_arr[1..3].try_into().unwrap();

assert_eq!(ok_elm, &[0, 1]);
assert_eq!(weird_elm, &[1, 2]);

assert_eq!(arr.element_offset(ok_elm), Some(0)); // Points to element 0
assert_eq!(arr.element_offset(weird_elm), None); // Points between element 0 and 1
```

--------------------------------

### SingleOwnerAccount Constructor and Configuration

Source: https://docs.rs/starknet/latest/starknet/accounts/single_owner/struct

Provides details on creating and configuring a SingleOwnerAccount instance.

```APIDOC
## POST /accounts/single_owner/new

### Description
Creates a new account controlled by a single signer.

### Method
POST

### Endpoint
`/accounts/single_owner/new`

### Parameters
#### Request Body
- **provider** (Provider) - Required - A `Provider` implementation that provides access to the Starknet network.
- **signer** (Signer) - Required - A `Signer` implementation that can generate valid signatures for this account.
- **address** (Felt) - Required - Account contract address.
- **chain_id** (Felt) - Required - Network chain ID.
- **encoding** (ExecutionEncoding) - Required - How `__execute__` calldata should be encoded.

### Response
#### Success Response (200)
- **account** (SingleOwnerAccount) - The newly created SingleOwnerAccount instance.

#### Response Example
```json
{
  "account": {
    "provider": "<provider_details>",
    "signer": "<signer_details>",
    "address": "<account_address>",
    "chain_id": "<chain_id>",
    "encoding": "<encoding_type>"
  }
}
```

## PUT /accounts/single_owner/set_block_id

### Description
Sets a new block ID to run queries against.

### Method
PUT

### Endpoint
`/accounts/single_owner/set_block_id`

### Parameters
#### Request Body
- **block_id** (BlockId) - Required - The new block ID to set.

### Response
#### Success Response (200)
- **account** (SingleOwnerAccount) - The updated SingleOwnerAccount instance with the new block ID set.

#### Response Example
```json
{
  "account": {
    "provider": "<provider_details>",
    "signer": "<signer_details>",
    "address": "<account_address>",
    "chain_id": "<chain_id>",
    "encoding": "<encoding_type>",
    "block_id": "<new_block_id>"
  }
}
```
```

--------------------------------

### Wasmtime Version for Starknet Benchmarks

Source: https://docs.rs/starknet/latest/starknet/core/index

Displays the version of the Wasmtime runtime used for benchmarking Starknet operations in a WebAssembly environment. This is crucial for reproducibility.

```bash
$ wasmtime --version
wasmtime-cli 21.0.1 (cedf9aa0f 2024-05-22)
```

--------------------------------

### Get Mutable Element by Index in VecDeque (Rust)

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/struct

Demonstrates how to get a mutable reference to an element at a specific index in a VecDeque using `get_mut`. This allows in-place modification of the element.

```rust
use std::collections::VecDeque;

let mut buf = VecDeque::new();
buf.push_back(3);
buf.push_back(4);
buf.push_back(5);
buf.push_back(6);
assert_eq!(buf[1], 4);
if let Some(elem) = buf.get_mut(1) {
    *elem = 7;
}
assert_eq!(buf[1], 7);
```

--------------------------------

### Rust: ContractFactory Deployment Methods

Source: https://docs.rs/starknet/latest/starknet/contract/struct

Methods for initiating contract deployments. `deploy_v3` is the recommended method for generating `INVOKE` v3 transactions, while `deploy` is deprecated and uses an unspecified transaction version.

```rust
pub const fn deploy_v3( &self, constructor_calldata: Vec<Felt>, salt: Felt, unique: bool, ) -> DeploymentV3<'_, A>
```

```rust
pub const fn deploy( &self, constructor_calldata: Vec<Felt>, salt: Felt, unique: bool, ) -> DeploymentV3<'_, A>
```

--------------------------------

### Add Element to Back and Get Mutable Ref in Rust (Nightly)

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/linked_list/struct

Experimental nightly feature `push_mut` to add an element to the back and get a mutable reference to it. This operation is O(1).

```rust
#![feature(push_mut)]
use std::collections::LinkedList;

let mut dl = LinkedList::from([1, 2, 3]);

let ptr = dl.push_back_mut(2);
*ptr += 4;
assert_eq!(dl.back().unwrap(), &6);
```

--------------------------------

### URL Serialization and Conversion

Source: https://docs.rs/starknet/latest/starknet/providers/struct

Documentation for URL serialization using Serde and conversion from string slices.

```APIDOC
## URL Serialization and Conversion

Documentation for URL serialization using Serde and conversion from string slices.

### `impl Serialize for Url`

Serializes this URL into a `serde` stream. This implementation requires the `serde` Cargo feature to be enabled.

#### Method
`serialize<S>( &self, serializer: S, ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>`
where S: Serializer,
Serializes the URL value into the given Serde serializer.

### `impl<'a> TryFrom<&'a str> for Url`

#### Type Alias
`type Error = ParseError`
The type returned in the event of a conversion error.

#### Method
`try_from(s: &'a str) -> Result<Url, <Url as TryFrom<&'a str>>::Error>`
Performs the conversion from a string slice to a URL.
```

--------------------------------

### U256 Constructors and Accessors

Source: https://docs.rs/starknet/latest/starknet/core/types/u256/struct

Methods for constructing a U256 from words and for accessing its low and high 128-bit components.

```APIDOC
## Implementations for U256

### `fn from_words(low: u128, high: u128) -> U256`

Constructs a U256 from the low 128 bits and the high 128 bits, similar to how they’re represented in Cairo.

### `fn low(&self) -> u128`

Gets the lower (least significant) 128 bits as u128.

### `fn high(&self) -> u128`

Gets the higher (most significant) 128 bits as u128.
```

--------------------------------

### Add Element to Front and Get Mutable Ref in Rust (Nightly)

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/linked_list/struct

Experimental nightly feature `push_mut` to add an element to the front and get a mutable reference to it. This operation is O(1).

```rust
#![feature(push_mut)]
use std::collections::LinkedList;

let mut dl = LinkedList::from([1, 2, 3]);

let ptr = dl.push_front_mut(2);
*ptr += 4;
assert_eq!(dl.front().unwrap(), &6);
```

--------------------------------

### Implement From<SigningKey> for LocalWallet (Rust)

Source: https://docs.rs/starknet/latest/starknet/signers/local_wallet/struct

Details the conversion from a SigningKey type into a LocalWallet. This implementation allows for seamless integration when a SigningKey is already available.

```rust
impl From<SigningKey> for LocalWallet {
    fn from(value: SigningKey) -> LocalWallet {
        // ... implementation details ...
    }
}
```

--------------------------------

### VarULE Encoding for Cow<'_, T>

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/borrow/enum

Details the methods for encoding `Cow<'_, T>` as a `VarULE` (Variable-length Unaligned Little-Endian), including functions to get the encoded length, write to a buffer, and get byte slices.

```Rust
impl<T> EncodeAsVarULE<T> for Cow<'_, T>
where T: VarULE + ToOwned + ?Sized,

fn encode_var_ule_as_slices<R>(&self, cb: impl FnOnce(&[&[u8]]) -> R) -> R

fn encode_var_ule_len(&self) -> usize

fn encode_var_ule_write(&self, dst: &mut [u8])
```

--------------------------------

### Rust: Creating a Vec using the vec! macro

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/index

Demonstrates the use of the `vec!` macro to efficiently create a `Vec<T>` (a growable array) with initial elements. This is a common convenience macro provided by the `alloc` crate.

```rust
fn main() {
    // Create a vector with initial elements
    let v = vec![1, 2, 3, 4, 5];
    println!("Vector: {:?}", v);

    // Create an empty vector
    let mut empty_v: Vec<i32> = vec![];
    empty_v.push(10);
    println!("Empty vector after push: {:?}", empty_v);
}

```

--------------------------------

### Rust Example: Basic FromStr usage with i32

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/str/trait

Shows a simple example of using the `FromStr` trait with the built-in `i32` type. It parses the string "5" into an `i32` value.

```rust
use std::str::FromStr;

let s = "5";
let x = i32::from_str(s).unwrap();

assert_eq!(5, x);
```

--------------------------------

### Get Minimum of Two Arc Values

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/sync/struct

Provides a method to get the minimum of two Arc values, leveraging the Ord implementation. This is useful for scenarios requiring selection of the smaller of two Arc-wrapped items.

```Rust
fn min(self, other: Self) -> Self
where Self: Sized
```

--------------------------------

### Starknet Class Hash Benchmarks (WebAssembly)

Source: https://docs.rs/starknet/latest/starknet/core/index

Benchmark results for Cairo 0 and Sierra class hash computations using the Wasmtime runtime. These times reflect performance in a WebAssembly environment.

```text
cairo0_class_hash       time:   [36.515 ms 36.526 ms 36.538 ms]
sierra_class_hash       time:   [22.550 ms 22.557 ms 22.567 ms]
```

--------------------------------

### Get Maximum of Two Arc Values

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/sync/struct

Provides a method to get the maximum of two Arc values, leveraging the Ord implementation. This is useful for scenarios requiring selection of the larger of two Arc-wrapped items.

```Rust
fn max(self, other: Self) -> Self
where Self: Sized
```

--------------------------------

### LinkedList Creation and Initialization

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/collections/linked_list/struct

Provides documentation for creating and initializing a LinkedList.

```APIDOC
## LinkedList

### Description
A doubly-linked list with owned nodes. The `LinkedList` allows pushing and popping elements at either end in constant time.

A `LinkedList` with a known list of items can be initialized from an array.

**Note**: It is almost always better to use `Vec` or `VecDeque` because array-based containers are generally faster, more memory efficient, and make better use of CPU cache.

### Method
N/A (Struct definition)

### Endpoint
N/A (Struct definition)

### Parameters
N/A

### Request Example
```rust
use std::collections::LinkedList;

let list = LinkedList::from([1, 2, 3]);
```

### Response
N/A (Struct definition)

```

```APIDOC
## LinkedList::new()

### Description
Creates an empty `LinkedList`.

### Method
`const fn new() -> LinkedList<T>`

### Endpoint
N/A (Associated function)

### Parameters
None

### Request Example
```rust
use std::collections::LinkedList;

let list: LinkedList<u32> = LinkedList::new();
```

### Response
#### Success Response (200)
- `LinkedList<T>` - An empty LinkedList.

### Response Example
```rust
// No direct response example, as it's a constructor.
```

```

```APIDOC
## LinkedList::new_in(alloc: A)

### Description
Constructs an empty `LinkedList<T, A>` with a specified allocator. This is a nightly-only experimental API.

### Method
`const fn new_in(alloc: A) -> LinkedList<T, A>`

### Endpoint
N/A (Associated function)

### Parameters
- **alloc** (A) - The allocator to use for the LinkedList.

### Request Example
```rust
#![feature(allocator_api)]

use std::alloc::System;
use std::collections::LinkedList;

let list: LinkedList<u32, _> = LinkedList::new_in(System);
```

### Response
#### Success Response (200)
- `LinkedList<T, A>` - An empty LinkedList with the specified allocator.

### Response Example
```rust
// No direct response example, as it's a constructor.
```

```

--------------------------------

### Get Mutable Element or Subslice by Index (Rust)

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/bstr/struct

Safely retrieves a mutable reference to an element or a subslice. Similar to `get`, but allows modification. Returns None if the index is out of bounds. Essential for in-place modifications.

```rust
let x = &mut [0, 1, 2];

if let Some(elem) = x.get_mut(1) {
    *elem = 42;
}
assert_eq!(x, &[0, 42, 2]);
```

--------------------------------

### Rust Example: `ThreadWaker` and `block_on`

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/task/trait

Demonstrates how to implement the `Wake` trait for a custom `ThreadWaker` and utilizes it within a `block_on` function to run a future to completion on the current thread. This example highlights task waking and polling mechanisms.

```rust
use std::future::Future;
use std::sync::Arc;
use std::task::{Context, Poll, Wake};
use std::thread::{self, Thread};
use core::pin::pin;

/// A waker that wakes up the current thread when called.
struct ThreadWaker(Thread);

impl Wake for ThreadWaker {
    fn wake(self: Arc<Self>) {
        self.0.unpark();
    }
}

/// Run a future to completion on the current thread.
fn block_on<T>(fut: impl Future<Output = T>) -> T {
    // Pin the future so it can be polled.
    let mut fut = pin!(fut);

    // Create a new context to be passed to the future.
    let t = thread::current();
    let waker = Arc::new(ThreadWaker(t)).into();
    let mut cx = Context::from_waker(&waker);

    // Run the future to completion.
    loop {
        match fut.as_mut().poll(&mut cx) {
            Poll::Ready(res) => return res,
            Poll::Pending => thread::park(),
        }
    }
}

block_on(async {
    println!("Hi from inside a future!");
});
```

--------------------------------

### URL Construction from File Path

Source: https://docs.rs/starknet/latest/starknet/providers/struct

Methods for constructing URL objects from file paths.

```APIDOC
## POST /url/from_file_path

### Description
Constructs a `Url` object from a given file path. This method is available when the `std` Cargo feature is enabled.

### Method
POST

### Endpoint
/url/from_file_path

### Parameters
#### Request Body
- **path** (string) - Required - The file path to convert into a URL.

### Request Example
```json
{
  "path": "/tmp/foo.txt"
}
```

### Response
#### Success Response (200)
- **url** (string) - The resulting URL string.

#### Response Example
```json
{
  "url": "file:///tmp/foo.txt"
}
```
```

```APIDOC
## POST /url/from_directory_path

### Description
Converts a directory path into a `file` scheme URL, ensuring a trailing slash. This method requires the `std` Cargo feature and returns an error if the path is not absolute or has an invalid prefix on Windows.

### Method
POST

### Endpoint
/url/from_directory_path

### Parameters
#### Request Body
- **path** (string) - Required - The directory path to convert.

### Request Example
```json
{
  "path": "/var/www"
}
```

### Response
#### Success Response (200)
- **url** (string) - The resulting URL with a trailing slash.

#### Response Example
```json
{
  "url": "file:///var/www/"
}
```
```

--------------------------------

### Rust: Example Usage of GetDisjointMutError

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/slice/enum

This Rust example demonstrates how to use the get_disjoint_mut function and handle the GetDisjointMutError. It shows cases where an index is out of bounds and where indices overlap, resulting in the respective error variants.

```rust
use std::slice::GetDisjointMutError;

let v = &mut [1, 2, 3];
assert_eq!(v.get_disjoint_mut([0, 999]), Err(GetDisjointMutError::IndexOutOfBounds));
assert_eq!(v.get_disjoint_mut([1, 1]), Err(GetDisjointMutError::OverlappingIndices));
```

--------------------------------

### Generic Blanket Implementations for Rust Types

Source: https://docs.rs/starknet/latest/starknet/providers/struct

Demonstrates common blanket implementations in Rust that apply to generic types, including `Any`, `Borrow`, `BorrowMut`, `CloneToUninit`, `Comparable`, and `Equivalent`. These implementations provide fundamental functionalities applicable to a wide range of types, including `Url`.

```Rust
impl<T> Any for T where T: 'static + ?Sized { fn type_id(&self) -> TypeId }
impl<T> Borrow<T> for T where T: ?Sized { fn borrow(&self) -> &T }
impl<T> BorrowMut<T> for T where T: ?Sized { fn borrow_mut(&mut self) -> &mut T }
impl<T> CloneToUninit for T where T: Clone { unsafe fn clone_to_uninit(&self, dest: *mut u8) }
impl<Q, K> Comparable<K> for Q where Q: Ord + ?Sized, K: Borrow<Q> + ?Sized { fn compare(&self, key: &K) -> Ordering }
impl<Q, K> Equivalent<K> for Q where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized { fn equivalent(&self, key: &K) -> bool }
```

--------------------------------

### Rust print! and println! Macros for Standard Output

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/index

Shows examples of the `print!` and `println!` macros for writing formatted strings to the standard output (stdout). These macros also aim to prevent intermediate allocations.

```rust
print!("Hello {}!", "world");
println!("I have a newline {}", "character at the end");
```

--------------------------------

### Rust Cow: is_owned() Example (Nightly)

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/borrow/enum

Example demonstrating the `is_owned` method for `Cow`, which is currently an unstable (nightly-only) feature. It checks if the `Cow` instance currently holds owned data, returning `true` if it does and `false` if it holds borrowed data.

```rust
#![feature(cow_is_borrowed)]
use std::borrow::Cow;

let cow: Cow<'_, str> = Cow::Owned("moo".to_string());
assert!(cow.is_owned());

let bull = Cow::Borrowed("...moo?");
assert!(!bull.is_owned());
```

--------------------------------

### Rust Cow: is_borrowed() Example (Nightly)

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/borrow/enum

Example demonstrating the `is_borrowed` method for `Cow`, which is currently an unstable (nightly-only) feature. It checks if the `Cow` instance currently holds borrowed data, returning `true` if it does and `false` if it holds owned data.

```rust
#![feature(cow_is_borrowed)]
use std::borrow::Cow;

let cow = Cow::Borrowed("moo");
assert!(cow.is_borrowed());

let bull: Cow<'_, str> = Cow::Owned("...moo?".to_string());
assert!(!bull.is_borrowed());
```

--------------------------------

### StarkNet Utility Methods

Source: https://docs.rs/starknet/latest/starknet/core/types/requests/index

Utility methods for network information.

```APIDOC
## GET /starknet_chainId

### Description
Retrieves the chain ID of the StarkNet network.

### Method
GET

### Endpoint
/starknet_chainId

### Response
#### Success Response (200)
- **result** (string) - The chain ID.

#### Response Example
```json
{
  "jsonrpc": "2.0",
  "result": "0x...",
  "id": 1
}
```

---

## GET /starknet_specVersion

### Description
Retrieves the supported StarkNet spec version.

### Method
GET

### Endpoint
/starknet_specVersion

### Response
#### Success Response (200)
- **result** (string) - The spec version string.

#### Response Example
```json
{
  "jsonrpc": "2.0",
  "result": "0.1.0",
  "id": 1
}
```
```

--------------------------------

### Get Port or Default Port from URL (Rust)

Source: https://docs.rs/starknet/latest/starknet/providers/struct

Explains how to get the port number from a URL, falling back to the known default port for schemes like http, https, ws, wss, and ftp. Returns None for unknown schemes without explicit ports.

```rust
use url::Url;

let url = Url::parse("foo://example.com")?;
assert_eq!(url.port_or_known_default(), None);

let url = Url::parse("foo://example.com:1456")?;
assert_eq!(url.port_or_known_default(), Some(1456));

let url = Url::parse("https://example.com")?;
assert_eq!(url.port_or_known_default(), Some(443));
```

--------------------------------

### Rust format! Positional Parameters Example

Source: https://docs.rs/starknet/latest/starknet/core/types/alloc/fmt/index

Illustrates how positional parameters work within the `format!` macro in Rust, showing both sequential ordering and explicit index referencing. It highlights the behavior when mixing explicit indices with default sequential arguments.

```Rust
format!("{1} {} {0} {}", 1, 2); // => "2 1 1 2"
```