storage-engine-playground/crates/query-storage/src/table.rs

//! Raw input relations with positional columns.
//!
//! Tables are the input to atom scans. They carry no column names: positions
//! are matched against an [`AtomPattern`](crate::atom::AtomPattern).

use crate::value::Value;

#[derive(Debug, Clone)]
pub struct Table {
    pub arity: usize,
    pub rows: Vec<Vec<Value>>,
}

impl Table {
    #[must_use]
    pub fn new(arity: usize) -> Self {
        Self {
            arity,
            rows: Vec::new(),
        }
    }

    /// # Panics
    /// Panics if any row's length differs from `arity`.
    #[must_use]
    pub fn from_rows(arity: usize, rows: Vec<Vec<Value>>) -> Self {
        for (i, row) in rows.iter().enumerate() {
            assert_eq!(
                row.len(),
                arity,
                "row {i} arity mismatch: expected {arity}, got {}",
                row.len(),
            );
        }
        Self { arity, rows }
    }

    /// # Panics
    /// Panics if `row.len() != self.arity`.
    pub fn push(&mut self, row: Vec<Value>) {
        assert_eq!(
            row.len(),
            self.arity,
            "row arity mismatch: expected {}, got {}",
            self.arity,
            row.len(),
        );
        self.rows.push(row);
    }
}