Lazo: A Smart Contract Language for the Bazo Blockchain

Lazo is a statically typed, imperative and non-turing complete programming language. Please refer to lazo-specification for the complete language features.

Background

The Bazo Blockchain is a research blockchain to test different mechanisms and algorithms. In the current version, there is a virtual machine available to interpret and execute IL codes on the Bazo Blockchain.

The goal of this bachelor thesis is to build a compiler, which compiles the smart contracts written in the Lazo language into the Bazo Byte Code for the Bazo Virtual Machine.

             Lazo Source Code
                    |
                    V               
            +---------------+
            |     Lexer     |
            +---------------+
                    |
                    V
            +---------------+
            |     Parser    |
            +---------------+
                    |
                    V
            +---------------+
            |    Checker    |
            +---------------+
                    |
                    V
            +---------------+
            |   Generator   |
            +---------------+                
                    |
                    V
              Bazo Byte Code

Result

• Link to technical documentation (Bachelor Thesis 2019)
• Complete Language Specification v1.0 (Term Project 2018)

Lazo Example

Note: Lazo is still under development. The example below contains only the currently available features. Please see lazo-specification/examples for real smart contract use cases.

contract SimpleContract {
    Map<int, int> balances

    constructor() {
        balances[0x01] = 10
        balances[0x02] = 2

        pay(0x01, 0x02, 5)
    }

    function void pay(int from, int to, int amount) {
        if (amount > 0 && balances[from] >= amount){
            balances[from] -= amount
            balances[to]   += amount
        }
    }
}

Usage

The Lazo tool works with the CLI commands. Run lazo to see all the available commands and their usages.

$ lazo
Lazo is a tool for managing Lazo source code on the Bazo Blockchain

Usage:
  lazo [flags]
  lazo [command]

Available Commands:
  compile     Compile the Lazo source code
  help        Help about any command
  run         Compile and run the lazo source code on Bazo VM
  version     Print the version number of Lazo

Flags:
  -h, --help   help for lazo

Use "lazo [command] --help" for more information about a command.

Example:

• lazo compile program.lazo: Compile the source file program.lazo through all stages into Bazo byte code.
• lazo compile program.lazo --stage=p: Compile the source code only until the parser stage.
• lazo run program.lazo: Compile the source file and execute generated byte code on Bazo VM

Development

Run ./scripts/set-hooks.sh to setup git hooks.

Dependency Management

Packages are managed by Go Modules.

Set the environment variable GO111MODULE=on and run go mod vendor to install all the dependencies into the local vendor directory.

Run Compiler from Source

go run main.go compile program.lazo

It will compile the given source code file "program.lazo".

Run Unit Tests

go test ./... 

It will run all tests in the current directory and all of its subdirectories.

To see the test coverage, run ./scripts/test.sh and then open the coverage.html file.

Run Lints

./scripts/lint.sh

It will run golint on all packages except the vendor directory.

Build Compiler

go build 

It will create an executable for the current operating system (e.g. lazo.exe in Windows).

Install Compiler

go install

It will build an executable and place it in the $GOPATH/bin directory. Thus, lazo command will be available in the terminal from anywhere.