Eugene Lazutkin

A micro-library of stream components for building custom JSON and JSONC processing pipelines with a minimal memory footprint — parse, filter, and transform JSON far larger than available memory with a SAX-inspired token API, on Node.js or Web Streams.

Bindings for RE2: fast, safe alternative to backtracking regular expression engines.

Chain functions, generators, Node streams, and Web streams into a pipeline with backpressure support.

Elegant minimalistic implementation of OOP with mixins + AOP in JavaScript for node.js and browsers.

Tight 2D packing of images into a sprite with a corresponding CSS.

stream-csv-as-json is a micro-library of stream components for building custom CSV processing pipelines with a minimal memory footprint, on Node.js or Web Streams. It can parse CSV files far exceeding available memory streaming individual primitives using a SAX-inspired API.

Tight 2D rectangle packer suitable for sprites.

stream-csv-enhanced is a collection of node.js 0.10 stream components for creating custom standard-compliant CSV processors, which requires a minimal memory footprint. It can parse CSV files far exceeding available memory. Even individual data items are streamed piece-wise. Streaming SAX-inspired event-based API is included as well.

Toolkit of 1→N stream combinators: broadcast, route, filter — Node Streams and Web Streams, with proper backpressure handling.

Toolkit to produce a fancy console output (boxes, tables, charts, colors).

Toolkit to make streamable scanners and parsers.

Zero-dependency ESM library for deep equality, deep clone, unification, and pattern matching with logical variables and wildcards. Handles circular references, Map, Set, URL, typed arrays, Date, RegExp, symbols, and property descriptors. Works in Node.js, Deno, Bun, and browsers.

Join values from multiple object-mode Readable streams into a single Readable, with proper backpressure handling.

Zero-dependency DynamoDB toolkit (AWS SDK v3) — Adapter with hooks, expression builders, batch/transaction chunking, mass operations, REST handler.

Create binary artifacts hosted by github and install them without compiling.

Helpers for AWS Cognito to build web applications with authentication/authorization

Zero-dependency data structures: linked lists (doubly/singly linked, circular), deques, ring buffers, unrolled lists, caches (LRU, LFU, SLRU, Clock, FIFO), heaps (binary, indexed, pairing), timer wheels, object pools, queues, stacks, splay trees, skip lists.

Koa middleware for AWS Cognito integration.

Angie Effects: browser-agnostic high performance Canvas implementation.

Yet to be explained JavaScript project.

OOP with mixins, AOP, chaining for ES6

Lightweight async task scheduling and concurrency control: schedulers, idle/frame/limited queues, throttle, debounce, batch, page lifecycle, random delays. Browsers, Node.js, Deno, Bun.

CLI micro- and macro-benchmarking for Node, Deno, and Bun — hot loops, ms-scale operations, and whole commands — with nonparametric statistics and significance testing.

Slices a Markdown file in segments, generates HTML, and applies a template to the result.

Slices a Markdown file in segments separating a front matter in YAML, generates HTML, and applies a template to the result. Useful to generate web pages.

Git credential helper that keeps its data store in an encrypted JSON using id_rsa or similar certificate.

Get/set using a dot-separated path from a JSON-like store object with optional multiple values.

Tiny, zero-dependency binary search for JavaScript and TypeScript. Every result is a valid Array.splice() index — no bounds checks, no off-by-one. Equivalent to std::lower_bound / bisect_left.

Embeddable Prolog-style logic engine for JavaScript: declarative rules, unification, backtracking search, and four solver drivers (sync/async × callback/generator). Useful for pattern matching with extraction, constraint search, type inference, planners, expert systems, and policy checks. ESM, single runtime dependency (deep6).

Run OS and shell commands using template tag functions. Same API in Node, Deno, and Bun. Web streams, TypeScript typings, zero dependencies.

My public web pages on github

Snippets and functions for data-forward and code-forward programming.

Statistics collector (GAE JS app)

Calculating a feature set using GA reports.

A simple Chrome extension to inspect performance-related properties of a web page

Transform AMD and UMD modules to CommonJS, globals, and so on.

No description.

WebP with Accept negotiation

Initial page loader toolkit for JS Web applications, based on Node.js backend

Zero-dependency toolkit for meta programming and OOP: name-casing conversions, property descriptors, aliases, prototype traversal, iterators, deep path access, option merging, and comparator adapters

AI-agent-first knowledge base over markdown. SQLite + sqlite-vec for fast lookup, semantic search, and typed-edge traversal; BGE embeddings; REST server (MCP planned).

Express middleware for AWS Cognito integration.

AWS Lambda adapter for dynamodb-toolkit — serves the standard REST route pack as a Lambda handler for API Gateway (REST / HTTP), Lambda Function URLs, and ALB. Delegates parsing, envelope building, and policy to dynamodb-toolkit/rest-core.

Express adapter for dynamodb-toolkit — mounts the standard REST route pack as Express middleware.

Fetch adapter for dynamodb-toolkit — serves the standard REST route pack as a (Request) → Promise<Response> handler. Runs on Cloudflare Workers, Deno Deploy, Bun.serve, Hono, itty-router, and Node's native fetch server.

Koa adapter for dynamodb-toolkit — mounts the standard REST route pack as Koa middleware.

TAP-inspired unit test library for Node, Deno, Bun, and browsers. ES modules, TypeScript, zero dependencies.

Micro AWS Website CDN with CDK

Puppeteer-based browser test runner for tape-six. Runs each test file in its own browser context (Chromium or Firefox). Works with Node, Deno, and Bun.

Playwright-based browser test runner for tape-six. Runs each test file in its own browser context (Chromium, Firefox, or WebKit). Works with Node, Deno, and Bun.

External merge sort and sorted-stream operations (mergeJoin, union, intersection, difference) for object-mode Node Readable streams. Part of the stream-chain / stream-json / stream-join family.

Process-isolated test runner for tape-six. Runs each test file in its own subprocess. Works with Node, Deno, and Bun. Supports TypeScript without transpilation.

Dojo demo of image resize using dojo.Stateful API

"Dojo already has that."

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A companion web site for dcl.

My playground for JavaScript bits.

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Build a self-describing search index from a GitHub wiki (or any Markdown docs) — the indexer for wiki-search.

My dotfiles managed by ChezMoi

A modern fetch-native HTTP I/O library for browsers and CLIs: caching, request dedup, retry, streaming, SSE, and transparent bundling. Zero dependencies.

Zero-dependency invariant checks that materialize into real tape-six assertions under test, and stay inert (or configurable) in production.

Pure Bash library for CLI utilities: ANSI colors & styles, text box layout, option parsing, and auto-generated help screens. Zero dependencies, Bash 4.0+.

No description.

Seamless integration between Rollup and PostCSS.

Minimal-dependency micro helper for developers of binary addons for Node that saves precompiled artifacts to GitHub releases, so later it can be retrieved from the cache rather than built. Save time for your users!

Service-worker sibling of double-meh: shared cache tier, cross-tab request coalescing, transparent bundling, invalidation hub, and version upgrades — composable modules plus a ready assembly. Works with or without double-meh.

Server-side bundler for the double-meh bundle protocol: one fetch-handler core, framework adapters as thin subpaths.

Compress middleware for koa