rustloclib

A Rust-aware lines-of-code counter library. Unlike generic LOC tools, rustloclib understands that Rust tests live alongside production code and correctly separates them — even in the same file.

Line types

Every line is classified into one of six types:

• code — production logic lines
• tests — test logic lines (#[test], #[cfg(test)], tests/)
• examples — example logic lines (examples/)
• docs — doc comments (///, //!, /** */, /*! */)
• comments — regular comments (//, /* */)
• blanks — whitespace-only lines

Quick start

[dependencies]
rustloclib = "0.8"

Count a workspace

use rustloclib::{count_workspace, CountOptions};

let result = count_workspace(".", CountOptions::new())?;
println!("Code: {}, Tests: {}, Docs: {}", result.total.code, result.total.tests, result.total.docs);

Count a single file

use rustloclib::count_file;

let stats = count_file("src/lib.rs")?;
println!("Code: {}, Tests: {}", stats.code, stats.tests);

Filter by crate or glob

use rustloclib::{count_workspace, CountOptions, FilterConfig};

let filter = FilterConfig::new().exclude("**/generated/**")?;
let result = count_workspace(".", CountOptions::new()
    .crates(vec!["my-lib".into()])
    .filter(filter))?;

Diff between commits

use rustloclib::{diff_commits, DiffOptions};

let diff = diff_commits(".", "HEAD~5", "HEAD", DiffOptions::new())?;
println!("Code: +{}/-{}", diff.total.added.code, diff.total.removed.code);

Working directory diff

use rustloclib::{diff_workdir, DiffOptions, WorkdirDiffMode};

let diff = diff_workdir(".", WorkdirDiffMode::Staged, DiffOptions::new())?;

Data pipeline

The library is organized into four stages:

source  →  data  →  query  →  output
Find       Parse    Filter    Format
files      & count  & sort    strings

Full pipeline example

use rustloclib::{
    count_workspace, CountOptions, CountQuerySet, LOCTable,
    Aggregation, LineTypes, Ordering,
};

// Stages 1–2: discover and count
let result = count_workspace(".", CountOptions::new())?;

// Stage 3: query (filter line types, aggregate, sort)
let queryset = CountQuerySet::from_result(
    &result,
    Aggregation::ByCrate,
    LineTypes::everything(),
    Ordering::by_code(),
);

// Stage 4: format for display
let table = LOCTable::from_count_queryset(&queryset);

Key types

All data types implement serde::Serialize and serde::Deserialize.

Acknowledgments

The parsing logic is adapted from cargo-warloc by Maxim Gritsenko (MIT licensed).

License

MIT License