Struct TableReader 

pub struct TableReader { /* private fields */ }

A table opened for streaming: its header is read up front, its rows on demand through TableReader::rows.

Implementations

impl TableReader

pub fn open(path: &str) -> Result<Self>

Open path and read its header. Parquet is recognised by extension; anything else is delimited text, gzip-decoded when it ends in .gz. A text header is the first line that does not start with ## (VCF- style meta lines are skipped), with one leading # dropped (#chr start end is a BED-style header).

pub fn path(&self) -> &str

pub fn header(&self) -> &[Box<str>]

Column names, in file order.

pub fn column_index(&self, name: &str) -> Option<usize>

Index of a column by exact name.

pub fn has_columns(&self, names: &[&str]) -> bool

true when every name is a column.

pub fn find_column(&self, candidates: &[&str]) -> Option<usize>

The first of candidates that is a column: for a field that different releases spell differently.

pub fn select(&self, names: &[&str]) -> Result<Vec<usize>>

Indices of names, in request order; a missing name is an error that lists what the file does have.

pub fn rows(&self, cols: &[usize]) -> Result<TableRows>

Stream the rows, each cut down to the columns at cols (in that order; repeats allowed). A text row too short for a requested column yields "" there; blank lines and # lines are skipped.