Struct FieldDefinition 

pub struct FieldDefinition {
    pub format: TableColumnFormat,
    pub offset: usize,
    pub name: String,
    pub scale: Option<f64>,
    pub zero: Option<f64>,
    pub null: Option<i64>,
    pub dimensions: Vec<usize>,
}

Everything the header says about one binary table column.

A column is more than its TFORMn type: TSCALn and TZEROn describe a linear transform from the stored entry to the physical value it stands for, and TNULLn names the stored entry that means “undefined”. decode applies all three, so callers see physical values rather than raw ones.

Fields

format: TableColumnFormat

TFORMn: this column’s type and repeat count.

offset: usize

Byte offset of this column from the start of a row.

name: String

TTYPEn, or an empty string for a column that carries no name.

scale: Option<f64>

TSCALn: the multiplier applied to a stored entry.

zero: Option<f64>

TZEROn: the offset added after scaling.

null: Option<i64>

TNULLn: the stored entry that marks an undefined value.

dimensions: Vec<usize>

TDIMn: the shape this column’s entry has, fastest-varying axis first.

Empty for a column with no TDIMn card, which is a plain run of TableColumnFormat::len elements. Value holds the elements flat either way; this says how to fold them.

Implementations

impl FieldDefinition

pub fn all_from_header( header: &Header, ) -> Result<Vec<Self>, Box<dyn Error + Send + Sync>>

Reads every column of header in order, resolving each one’s offset from the widths of the columns before it.

pub fn decode(&self, row: &[u8], heap: &[u8]) -> Result<Value>

Decodes this column out of row, which must be a whole row of the table.

heap is the table’s heap, which only a variable length array column reads from; pass an empty slice for a table that has none.

Trait Implementations

impl Clone for FieldDefinition

fn clone(&self) -> FieldDefinition

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FieldDefinition

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

Formats the value using the given formatter.

impl PartialEq for FieldDefinition

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FieldDefinition