Struct tqdb::Database

pub struct Database<T>(_);

A database stores many items in an unordered fashion.

Examples

We can create a database using any type.

use tqdb::Database;
let db1: Database<i32> = Database::new();
let db2: Database<&u8> = Database::from_iter("hello world".as_bytes().into_iter());
struct Vec2 { x: i32, y: i32 };
let db3: Database<Vec2> = Database::from_iter(vec![ Vec2 { x: 0, y: 5 }, Vec2 { x: 100, y: 50 } ]);

If the type is serializable, we can even save it as json!

use serde::{Serialize, Deserialize};
#[derive(Serialize, Deserialize)]
struct Vec2 { x: i32, y: i32 };

use tqdb::Database;
let db1: Database<i32> = Database::new();
let db2: Database<&u8> = Database::from_iter("hello world".as_bytes().into_iter());
let db3: Database<Vec2> = Database::from_iter(vec![ Vec2 { x: 0, y: 5 }, Vec2 { x: 100, y: 50 } ]);

db1.save_to_file("db1.json")?;
db2.save_to_file("db2.json")?;
db3.save_to_file("db3.json")?;

We can query a database using macros!

We can search a database…

use tqdb::{Database, Query, search, search_mut, remove};
let db = Database::from_iter(1..10);
let found_items = search!(&db match |it: &i32| *it >= 5 && *it <= 7);

…search a database (with mutable access)

let found_items_mut1 = search_mut!(&mut db match |it: &i32| *it >= 5 && *it <= 7);
// or
let found_items_mut2 = search!(&mut db match |it: &i32| *it >= 5 && *it <= 7);

…and remove items easily!

let removed_items = remove!(&mut db match |it: &i32| *it >= 5 && *it <= 7);

Implementations

impl<T> Database<T>

pub fn search(&self, query: Query<T>) -> impl Iterator<Item = &T>

We can search a database with a Query. Usually done with the search! macro.

Examples

Simple query

use tqdb::{Database, Query};
let db = Database::from_iter(1..10);
assert!([&1,&2,&3,&4].into_iter().eq(db.search(Query::new(|it: &i32| *it < 5))));

We can also chain together queries with the & and | operators

// cool AND query
assert!([&3,&4].into_iter().eq(
    db.search( Query::new(|it: &i32| *it < 5) & Query::new(|it: &i32| *it > 2) )));
// cool OR query
assert!([&1,&2,&5,&6,&7,&8,&9].into_iter().eq(
    db.search( Query::new(|it: &i32| *it >= 5) | Query::new(|it: &i32| *it <= 2) )));

pub fn search_mut(&mut self, query: Query<T>) -> impl Iterator<Item = &mut T>

We can search a database with a Query. Usually done with the search_mut! macro.

Examples

Simple query

use tqdb::{Database, Query};
let mut db = Database::from_iter(1..10);
assert!([&mut 1,&mut 2,&mut 3,&mut 4].into_iter().eq(
    db.search_mut(Query::new(|it: &i32| *it < 5))));

We can also chain together queries with the & and | operators

// cool AND query
assert!([&mut 3,&mut 4].into_iter().eq(
    db.search( Query::new(|it: &i32| *it < 5) & Query::new(|it: &i32| *it > 2) )));
// cool OR query
assert!([&mut 1,&mut 2,&mut 5,&mut 6,&mut 7,&mut 8,&mut 9].into_iter().eq(
    db.search( Query::new(|it: &i32| *it > 4) | Query::new(|it: &i32| *it < 3) )));

pub fn insert(&mut self, item: T)

We can insert an item into a database

Example

use tqdb::Database;
let mut db: Database<i32> = Database::new();
db.insert(0);

pub fn insert_unique(&mut self, item: T) -> Result<(), DatabaseError> where
    T: PartialEq, 

We can insert a unique item into a database

Raises

May raise an DatabaseError::DuplicateItemInsertion if trying to insert a duplicate item.

Example

use tqdb::Database;
let mut db: Database<i32> = Database::new();
assert!(db.insert_unique(0).is_ok());
assert!(db.insert_unique(1).is_ok());
assert!(db.insert_unique(0).is_err());
assert!(db.insert_unique(1).is_err());
assert!(db.insert_unique(2).is_ok());

pub fn remove(&mut self, query: Query<T>) -> impl Iterator<Item = T> + '_

We can remove an item from a database with a Query. Usually done with remove! macro.

Examples

Simple query

use tqdb::{Database, Query};
let mut db = Database::from_iter(1..10);
assert!([1,2,3,4].into_iter().eq(
    db.remove(Query::new(|it: &i32| *it < 5))));
assert!([&5,&6,&7,&8,&9].into_iter().eq(
    db.iter()));

pub fn save(&self, w: &mut dyn Write) -> Result<(), DatabaseError> where
    T: Serialize, 

Save the database to a Writer

Raises:

May raise a DatabaseError::BadWrite if we could not successfully write to the writer.

Examples

// given a simple writer
struct StringWriter(String);
impl std::io::Write for StringWriter {
    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
        self.0.write_str(std::str::from_utf8(buf).unwrap()).unwrap();
        Ok(buf.len())
    }

    fn flush(&mut self) -> std::io::Result<()> {
        Ok(())
    }
}

let db = Database::from_iter(1..10);
let mut output = StringWriter { 0: String::new() };
assert!(db.save(&mut output).is_ok());
assert_eq!("[1,2,3,4,5,6,7,8,9]", output.0.as_str());

pub fn save_to_file<P: AsRef<Path>>(&self, p: P) -> Result<(), DatabaseError> where
    T: Serialize, 

Allows us to save the database as json to a file.

Raises:

May raise a DatabaseError::BadWrite if we could not successfully write to the file.

Examples:

use tqdb::Database;
let db: Database<i32> = Database::from_iter(1..10);
db.save_to_file("test.db.json")?;

pub fn new() -> Self

Lets us construct a new empty database.

pub fn iter(&self) -> impl Iterator<Item = &T> + '_

Lets us see all the items in our database

Examples

use tqdb::Database;
let db: Database<i32> = Database::from_iter(1..10);
for item in db.iter() {
    println!("Item is {}!", item);
}

pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut T> + '_

Allows us to see all of the items in our database and mutate them

Examples

use tqdb::Database;
let mut db: Database<i32> = Database::from_iter(1..10);
for mut item in db.iter_mut() {
    println!("Item was {}!", item);
    *item += 5;
    println!("Item is now {}!", item);
}

Trait Implementations

impl<T: Clone> Clone for Database<T>

fn clone(&self) -> Database<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Database<T>

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

Formats the value using the given formatter.

impl<T: Default> Default for Database<T>

fn default() -> Database<T>

Returns the “default value” for a type.

impl<'de, T> Deserialize<'de> for Database<T> where
    T: Deserialize<'de>, 

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where
    __D: Deserializer<'de>, 

Deserialize this value from the given Serde deserializer.

impl<T> Extend<T> for Database<T>

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

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

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

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

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

Reserves capacity in a collection for the given number of additional elements.

impl<T> From<Vec<T, Global>> for Database<T>

fn from(v: Vec<T>) -> Self

Performs the conversion.

impl<T> FromIterator<T> for Database<T>

fn from_iter<It: IntoIterator<Item = T>>(iter: It) -> Self

Creates a value from an iterator.

impl<T: Hash> Hash for Database<T>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<T> IntoIterator for Database<T>

type Item = T

The type of the elements being iterated over.

type IntoIter = <Vec<T> as IntoIterator>::IntoIter

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<T: Ord> Ord for Database<T>

fn cmp(&self, other: &Database<T>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<T: PartialEq> PartialEq<Database<T>> for Database<T>

fn eq(&self, other: &Database<T>) -> bool

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

fn ne(&self, other: &Database<T>) -> bool

This method tests for !=.

impl<T: PartialOrd> PartialOrd<Database<T>> for Database<T>

fn partial_cmp(&self, other: &Database<T>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<T> Serialize for Database<T> where
    T: Serialize, 

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where
    __S: Serializer, 

Serialize this value into the given Serde serializer.

impl<R: Read, T: DeserializeOwned> TryFrom<BufReader<R>> for Database<T>

type Error = DatabaseError

The type returned in the event of a conversion error.

fn try_from(r: BufReader<R>) -> Result<Self, DatabaseError>

Performs the conversion.

impl<T: Eq> Eq for Database<T>

impl<T> StructuralEq for Database<T>

impl<T> StructuralPartialEq for Database<T>