A Rust compiler written in PHP that emits x86-64 Linux ELF binaries directly (no LLVM, no assembler, no linker). Implements ownership checking, borrow checking, type checking, move semantics, generics, traits, closures, and iterators. Useful if you need to compile Rust on a shared hosting server from 2008 where the only installed runtime is PHP.

This article is both an introduction to a tool I have been working on called jsongrep, as well as a technical explanation of the internal search engine it uses. I also discuss the benchmarking strategy used to compare the performance of jsongrep against other JSON path-like query tools and implementations.

In this post I'll first show you the tool, then explain why it's fast (conceptually), then how it's fast (the automata theory), and finally prove it (benchmarks).