Trait ProgressCallback 

pub trait ProgressCallback: Send + Sync {
    // Required methods
    fn inc(&self, n: u64);
    fn parsing_started(&self, path: &str);
}

Trait for receiving progress updates during data parsing.

Implement this trait to display a progress bar, log progress, or perform any other action when the parser makes forward progress.

Example

use std::sync::Arc;
use readstat::ProgressCallback;

struct LogProgress;

impl ProgressCallback for LogProgress {
    fn inc(&self, n: u64) {
        println!("Processed {n} more rows");
    }
    fn parsing_started(&self, path: &str) {
        println!("Parsing file: {path}");
    }
}

Required Methods

fn inc(&self, n: u64)

Called to advance progress by n rows. Invoked once per chunk, just after that chunk finishes parsing, so n counts rows already completed (the chunk size) — the displayed position stays in step with work done.

fn parsing_started(&self, path: &str)

Called once when parsing begins for the file at path.

Implementations should be idempotent: the contract is a single “parsing started” notification per parse, but callers may invoke it more than once (e.g. the CLI guards against this internally).

Implementors