Struct tubular::Row

pub struct Row<'d> { /* fields omitted */ }

An opaque container for arbitrary types plucked from different Columns

Rows only exist derivatively from a DataFrame that holds them. They hold boxed references to the values owned by Columns.

Because Rows exist ephemerally, the number of cells and their types can't be known at compile time. The values are stored as Anys and must be downcast into the appropriate types to access the interior values. Row allows you to access values by specifying the column name or offset and supplying a type parameter which is forwarded to [downcast_ref] for you.

use tubular::DataFrame;

let mut df = DataFrame::default();
df.push("Fruits", &["apple", "pear", "mango"]);
df.push("Quantity", &[16, 25, 3]);
df.push("Organic", &[true, true, false]);

for row in df.rows() {
    let organic = *row.column_name::<bool>("Organic");
    let label = if organic { "Organic" } else { "" };
    println!("{} Fruit {} - {} available",
        label,
        row.column_name::<String>("Fruits"),
        row.column_name::<i32>("Quantity")
    );
}

Methods

impl<'d> Row<'d>

pub fn len(&self) -> usize

Number of cells in this Row

pub fn column_index<T>(&'d self, index: usize) -> &'d T where
    T: 'static + ColumnType, 

Returns the cell value by number and downcasts to T simultaneously.

Panics

This method panics if T does not match the type of the value at the provided index.

pub fn column_name<T>(&'d self, index: &'static str) -> &'d T where
    T: 'static + ColumnType, 

Returns the cell value by column name and downcasts to T simultaneously.

Panics

This method panics if T does not match the type of the value at the provided name.

Trait Implementations

impl<'d> Debug for Row<'d>

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

Formats the value using the given formatter.

impl<'d> Default for Row<'d>

fn default() -> Row<'d>

Returns the "default value" for a type.

impl<'d> Index<&'static str> for Row<'d>

type Output = Box<dyn Any>

The returned type after indexing.

fn index(&self, index: &'static str) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<'d> Index<String> for Row<'d>

type Output = Box<dyn Any>

The returned type after indexing.

fn index(&self, index: String) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<'d> Index<usize> for Row<'d>

type Output = Box<dyn Any>

The returned type after indexing.

fn index(&self, index: usize) -> &Self::Output

Performs the indexing (container[index]) operation.