Struct Header

pub struct Header {
    pub table_id: TableId,
    pub table_name: Box<str>,
    pub fields: Vec<Column>,
    pub constraints: BTreeMap<ColList, Constraints>,
}

Fields

table_id: TableId

table_name: Box<str>

fields: Vec<Column>

constraints: BTreeMap<ColList, Constraints>

Implementations

impl Header

pub fn new( table_id: TableId, table_name: Box<str>, fields: Vec<Column>, uncombined_constraints: impl IntoIterator<Item = (ColList, Constraints)>, ) -> Self

Create a new header.

uncombined_constraints will be normalized using combine_constraints.

pub fn clone_for_error(&self) -> Self

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 column_pos(&self, col: FieldName) -> Option<ColId>

Finds the index of the column with a matching FieldName.

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

pub fn field_name(&self, col: FieldName) -> Option<(ColId, FieldName)>

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

pub fn project(&self, cols: &[ColExpr]) -> Result<Self, RelationError>

Project the ColExprs & the Constraints that referenced them

pub fn project_col_list(&self, cols: &ColList) -> Self

Project the ourself onto the ColList, keeping constraints that reference the columns in the ColList. Does not change ColIDs.

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

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

Trait Implementations

impl Clone for Header

fn clone(&self) -> Header

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Header

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

Formats the value using the given formatter.

impl Display for Header

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

Formats the value using the given formatter.

impl Hash for Header

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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Header

fn eq(&self, other: &Header) -> bool

Tests for self and other values to be equal, and is used by ==.

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

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