Struct spacetimedb_lib::relation::Header

pub struct Header {
    pub table_name: String,
    pub fields: Vec<Column>,
    pub constraints: Vec<(ColList, Constraints)>,
}

Fields

table_name: String

fields: Vec<Column>

constraints: Vec<(ColList, Constraints)>

Implementations

impl Header

pub fn new( table_name: String, fields: Vec<Column>, constraints: Vec<(ColList, Constraints)> ) -> Header

pub fn clone_for_error(&self) -> Header

Equivalent to what Clone::clone would do.

Header intentionally does not implement Clone, as we can’t afford to clone it in normal execution paths. However, we don’t care about performance in error paths, and we need to embed owned Headers in error objects to report useful messages.

pub fn from_product_type(table_name: String, fields: ProductType) -> Header

pub fn to_product_type(&self) -> ProductType

pub fn for_mem_table(fields: ProductType) -> Header

pub fn as_without_table_name(&self) -> HeaderOnlyField<'_>

pub fn ty(&self) -> ProductType

pub fn find_by_name(&self, field_name: &str) -> Option<&Column>

pub fn column_pos<'a>(&'a self, col: &'a FieldName) -> Option<ColId>

pub fn column_pos_or_err<'a>( &'a self, col: &'a FieldName ) -> Result<ColId, RelationError>

pub fn find_pos_by_name(&self, name: &str) -> Option<ColId>

Finds the position of a field with name.

pub fn column<'a>(&'a self, col: &'a FieldName) -> Option<&'a Column>

pub fn has_constraint(&self, field: &FieldName, constraint: Constraints) -> bool

pub fn project( &self, cols: &[impl Into<FieldExpr> + Clone] ) -> Result<Header, RelationError>

Project the FieldExpr & the Constraints that referenced them

pub fn extend(&self, right: &Header) -> Header

Adds the fields & Constraints from right to this Header, renaming duplicated fields with a counter like a, a => a, a0.

Trait Implementations

impl Debug for Header

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

Formats the value using the given formatter.

impl Display for Header

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

Formats the value using the given formatter.

impl From<&TableSchema> for Header

fn from(value: &TableSchema) -> Header

Converts to this type from the input type.

impl From<AlgebraicType> for Header

fn from(value: AlgebraicType) -> Header

Converts to this type from the input type.

impl From<Header> for ProductType

fn from(value: Header) -> ProductType

Converts to this type from the input type.

impl From<ProductType> for Header

fn from(value: ProductType) -> Header

Converts to this type from the input type.

impl Hash for Header

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

where __H: Hasher,

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Header

fn eq(&self, other: &Header) -> 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 !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Header

impl StructuralPartialEq for Header