re2js is a pure JavaScript port of Google's RE2 regular expression engine, providing linear-time O(n) matching and protection against ReDoS attacks. It implements a full compilation pipeline: parsing RE2 syntax into an AST, simplifying the expression, compiling into a bytecode instruction set (Prog), and executing via multiple engines (DFA, NFA, OnePass, Backtracker, Prefilter). The library exposes a Java-style Matcher API with find, matches, replaceAll, and supports named capture groups, lookbehinds (linear-time), and both JS and Java replacement string dialects. It is distributed as an npm package supporting ESM, CJS, and UMD, with TypeScript declarations, and is tested across Node.js, Bun, Deno, and browsers. The architecture follows Russ Cox's regexp articles and uses sparse sets for efficient NFA simulation. Unicode tables for categories, scripts, and case folding are generated from @unicode/unicode-17.0.0 and decoded lazily.
STC (Smart Template Containers) is a mature, type-safe generic container and algorithm library for C99/C11. It is not an application or service; it is a library component that developers link into systems programs, embedded code, games, and simulations. The library provides macro-instantiated generic containers (vec, list, deque, stack, queue, priority queue, hash map, hash set, sorted map, sorted set, bitset), string types with small-string optimization (cstr, csview), multi-dimensional array views (cspan), smart pointers (box, arc, rc), a regular expression engine (cregex), a stackful coroutine framework, random number generators, and algorithms such as sorting, filtering, and binary search. The code implements the actual functionality; the README and docs describe usage, but the headers and src tree are the ground truth. The architecture is a hybrid header-only and compiled library. Templated containers are generated at compile time by a sophisticated macro trait system (via i_key, i_type, c_pro_key, etc.), while non-templated facilities like cstr, cregex, cspan, and random are partially implemented in src/ and linked as libstc. Public entry points are the headers under include/stc/; the build supports both Makefile and Meson, with examples and tests under examples/ and tests/. External dependencies are minimal, essentially the C11 standard library only, with compiler-specific pragmas and intrinsics for GCC, Clang, MSVC, and TCC. Data flows are primarily in-memory: containers own and manage elements, string operations transform UTF-8 text, regex compiles and executes NFA graph matching, and coroutines yield and resume across tasks. The codebase demonstrates strong engineering practice: a custom test harness (ctest.h), CI with sanitizers across three OSes, extensive API documentation, and a large examples corpus. The macro-based generic system is clever and powerful but carries the usual debugging and tooling complexity; deprecated aliases still exist from API churn. Overall this is a high-quality, reusable C library with several notably self-contained subsystems that could be lifted into other projects.
ztk is a CLI proxy that reduces LLM token consumption by intercepting and compressing shell command output. It sits between AI agents (Claude Code, Cursor, Gemini CLI) and the shell, executing commands normally but returning filtered output through a six-stage pipeline. The tool removes noise like diff metadata, test runner verbosity, and redundant directory listings while preserving essential information such as error messages and exit codes. Built in Zig with zero dependencies, it features a Thompson NFA regex engine for runtime filters, SIMD-accelerated text processing, and an mmap'd session cache to avoid repeated output for unchanged commands.