ZK Circuit Compiler

A zero-knowledge circuit compiler that transforms high-level programs into arithmetic circuits and R1CS constraint systems.

Features

• High-level language with public/private inputs and assertions
• SSA intermediate representation
• Circuit optimization (constant folding, dead code elimination)
• R1CS constraint system generation
• Witness calculation and verification

Grammar

program = statement*
statement = "public" IDENT
          | "private" IDENT
          | "const" IDENT "=" NUMBER
          | "let" IDENT "=" expr
          | "return" expr
          | "assert" expr "==" expr
expr = term ("+" term | "*" term)*
term = IDENT | NUMBER | "(" expr ")"

Usage

# Compile only
cargo run examples/simple.zk

# Compile and execute
cargo run examples/simple.zk inputs/inputs.toml

Generates:

• circuit/simple.json - Circuit gates
• circuit/simple.r1cs - R1CS constraints
• circuit/simple.witness - Execution trace

Architecture

The compiler pipeline:

1. Lexer → tokens
2. Parser → AST
3. SSA conversion → intermediate form
4. Optimization → constant folding, dead code elimination
5. Circuit generation → arithmetic gates
6. R1CS generation → constraint matrix
7. Witness calculation → execution with inputs

Current State

Uses i32 arithmetic for simplicity. Production ZK requires finite field arithmetic but my aim with this project was to explore the different compiler techniques.

Examples

Check examples/ for test programs showing language features and optimizations. The current example files end with .zk, the files ending in .mc were used for early testing.