explaingit

gildo/hai

Analysis updated 2026-07-17 · repo last pushed 2010-06-15

★ 1Audience · researcherComplexity · 4/5DormantSetup · hard

TLDR

A personal learning project building a toy compiler from scratch using Flex, Bison, and LLVM to understand how programming languages turn into machine code.

Mindmap

mindmap
  root((Toy compiler))
    What it does
      Learn compiler building
      Tokenize source code
      Generate machine code
    Tech stack
      Flex
      Bison
      LLVM
    Use cases
      Study compiler internals
      Experiment with language design
      Document learning journey
    Audience
      Students
      Researchers
      CS hobbyists

Code map

Detail Auto

An interactive map of this repo's files and how they connect — its source is parsed live in your browser. Click Visualize to build it.

filefunction / class

What do people build with it?

USE CASE 1

Study how a compiler tokenizes, parses, and generates machine code using Flex, Bison, and LLVM.

USE CASE 2

Use as a sandbox to experiment with compiler and language design fundamentals.

USE CASE 3

Learn how languages like Python or Rust transform readable code into executable programs.

USE CASE 4

Document a personal learning journey into how compilers work under the hood.

What is it built with?

FlexBisonLLVMC

How does it compare?

gildo/hai0xallam/posthog0xallam/search-engine
Stars111
Language—PythonC++
Last pushed2010-06-152026-03-262023-08-23
MaintenanceDormantMaintainedDormant
Setup difficultyhardmoderatehard
Complexity4/53/53/5
Audienceresearcherpm founderdeveloper

Figures from each repo's GitHub metadata at analysis time.

How do you get it running?

Difficulty · hard Time to first run · 1day+

Requires Flex, Bison, and LLVM installed and understood before the toy compiler can be built or extended.

Copy-paste prompts

Prompt 1
Explain how Flex and Bison work together to turn source code into a parsed structure.
Prompt 2
Walk me through what LLVM does with the parsed structure to produce runnable machine code.
Prompt 3
Help me extend this toy compiler to support a new simple language feature.
Prompt 4
What's a good next step after this project to learn more about compiler design?

Frequently asked questions

What is hai?

A personal learning project building a toy compiler from scratch using Flex, Bison, and LLVM to understand how programming languages turn into machine code.

Is hai actively maintained?

Dormant — no commits in 2+ years (last push 2010-06-15).

How hard is hai to set up?

Setup difficulty is rated hard, with roughly 1day+ to a first successful run.

Who is hai for?

Mainly researcher.

Open on GitHub → Explain another repo

This repo across BitVibe Labs

Verify against the repo before relying on details.

Alternatives & similar repos