Trait BaseValue

pub trait BaseValue:
    Clone
    + Hash
    + Eq
    + Any
    + Debug
    + Send
    + Sync {
    const MAY_UNBOX: bool = false;

    // Provided methods
    fn intern(&self, table: &InternTable<Self, Value>) -> Value { ... }
    fn as_any(&self) -> &(dyn Any + 'static) { ... }
    fn try_box(&self) -> Option<Value> { ... }
    fn try_unbox(_val: Value) -> Option<Self> { ... }
}

A simple data type that can be interned in a database.

Most callers can simply implement this trait on their desired type, with no overrides needed. For types that are particularly small, users can override BaseValue::try_box and BaseValue::try_unbox methods and set BaseValue::MAY_UNBOX to true to allow the Rust value to be stored in-place in a Value.

Regardless, all base value types should be registered in a BaseValues instance using the BaseValues::register_type method before they can be used in the database.

Provided Associated Constants

const MAY_UNBOX: bool = false

Provided Methods

fn intern(&self, table: &InternTable<Self, Value>) -> Value

fn as_any(&self) -> &(dyn Any + 'static)

fn try_box(&self) -> Option<Value>

fn try_unbox(_val: Value) -> Option<Self>

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl BaseValue for &'static str

impl BaseValue for bool

fn try_unbox(val: Value) -> Option<bool>

see bool::try_box

fn try_box(&self) -> Option<Value>

To optimize storage, we map Value 1 to true and 0 to false in the implementation. As an example, the subsumed column of a table has type bool.

use egglog_core_relations::BaseValue;
let true_value = true.try_box().unwrap();
let false_value = false.try_box().unwrap();
assert_eq!(bool::try_unbox(true_value).unwrap(), true);
assert_eq!(bool::try_unbox(false_value).unwrap(), false);

const MAY_UNBOX: bool = true

impl BaseValue for i8

const MAY_UNBOX: bool = true

fn try_unbox(val: Value) -> Option<i8>

fn try_box(&self) -> Option<Value>

impl BaseValue for i16

const MAY_UNBOX: bool = true

fn try_unbox(val: Value) -> Option<i16>

fn try_box(&self) -> Option<Value>

impl BaseValue for i32

const MAY_UNBOX: bool = true

fn try_unbox(val: Value) -> Option<i32>

fn try_box(&self) -> Option<Value>

impl BaseValue for i64

const MAY_UNBOX: bool = true

fn try_box(&self) -> Option<Value>

fn try_unbox(val: Value) -> Option<i64>

impl BaseValue for isize

const MAY_UNBOX: bool = true

fn try_box(&self) -> Option<Value>

fn try_unbox(val: Value) -> Option<isize>

impl BaseValue for u8

const MAY_UNBOX: bool = true

fn try_unbox(val: Value) -> Option<u8>

fn try_box(&self) -> Option<Value>

impl BaseValue for u16

const MAY_UNBOX: bool = true

fn try_unbox(val: Value) -> Option<u16>

fn try_box(&self) -> Option<Value>

impl BaseValue for u32

const MAY_UNBOX: bool = true

fn try_unbox(val: Value) -> Option<u32>

fn try_box(&self) -> Option<Value>

impl BaseValue for u64

const MAY_UNBOX: bool = true

fn try_box(&self) -> Option<Value>

fn try_unbox(val: Value) -> Option<u64>

impl BaseValue for ()

fn try_unbox(_val: Value) -> Option<()>

To optimize storage, we map Value 0 to unit type.

use egglog_core_relations::BaseValue;
let unit_value = ().try_box().unwrap();
assert_eq!(<()>::try_unbox(unit_value).unwrap(), ());

const MAY_UNBOX: bool = true

fn try_box(&self) -> Option<Value>

impl BaseValue for usize

const MAY_UNBOX: bool = true

fn try_box(&self) -> Option<Value>

fn try_unbox(val: Value) -> Option<usize>

impl BaseValue for String

impl BaseValue for Ratio<i64>

Implementors

impl BaseValue for ResolvedFunction

impl<T> BaseValue for Boxed<T>

where T: Hash + Eq + Debug + Clone + Send + Sync + 'static,