Trait IndexingMutationExt

Source

pub trait IndexingMutationExt {
    // Required methods
    fn get_index_mut(&mut self, index: &Value) -> Result<&mut Value, Error>;
    fn get_indices_mut(
        &mut self,
        index: &Value,
    ) -> Result<Vec<&mut Value>, Error>;
    fn set_index(&mut self, index: &Value, value: Value) -> Result<(), Error>;
    fn insert_at(&mut self, index: &Value, value: Value) -> Result<(), Error>;
    fn delete_index(&mut self, index: &Value) -> Result<Value, Error>;
}

Expand description

A trait for indexing operations that can mutate the value

Required Methods§

Source

fn get_index_mut(&mut self, index: &Value) -> Result<&mut Value, Error>

Get a value from an index Returns a mutable reference to the value, or an Error::Index if the index is not found

§Examples

use polyvalue::{Value};
use polyvalue::types::{Object};
use polyvalue::operations::{IndexingOperationExt, IndexingMutationExt};

let mut b = Object::try_from(vec![("a", 1), ("b", 2)]).unwrap();
let index = Value::from("b");
let result = b.get_index_mut(&index).unwrap();
*result = Value::from(3);

assert_eq!(b.get_index(&index).unwrap(), Value::from(3));

Source

fn get_indices_mut(&mut self, index: &Value) -> Result<Vec<&mut Value>, Error>

Get values from one or more indices, mutably Returns a vector of references to the values, or an Error::Index if any of the indices are not found

Acts as a convenience wrapper around get_index where array values are treated as a set of indices

Source

fn set_index(&mut self, index: &Value, value: Value) -> Result<(), Error>

Set a value at an index Returns an Error::Index if the index is not found

§Examples

use polyvalue::{Value};
use polyvalue::operations::{IndexingOperationExt, IndexingMutationExt};

let mut a = Value::from(vec![Value::from(1), Value::from(2), Value::from(3)]);
let index = Value::from(1);
a.set_index(&index, Value::from(4)).unwrap();
assert_eq!(a.get_index(&index).unwrap(), Value::from(4));

Source

fn insert_at(&mut self, index: &Value, value: Value) -> Result<(), Error>

Insert a value at an index Returns an Error::Index if the index is out of bounds

§Examples

use polyvalue::{Value};
use polyvalue::operations::{IndexingOperationExt, IndexingMutationExt};

let mut a = Value::from(vec![Value::from(1), Value::from(2), Value::from(3)]);
let index = Value::from(1);
a.insert_at(&index, Value::from(4)).unwrap();
assert_eq!(a.get_index(&index).unwrap(), Value::from(4));

Source

fn delete_index(&mut self, index: &Value) -> Result<Value, Error>

Delete a value at an index Returns an Error::Index if the index is not found

§Examples

use polyvalue::{Value};
use polyvalue::operations::{IndexingOperationExt, IndexingMutationExt};

let mut a = Value::from(vec![Value::from(1), Value::from(2), Value::from(3)]);
let index = Value::from(1);
a.delete_index(&index).unwrap();