Tealang

High-level language for Algorand Smart Contracts at Layer-1 and its low-level TEAL v6 language. The goal is to abstract the stack-based Algorand Virtual Machine and provide imperative Go/JS/Python-like syntax.

Language Features

• Integer and bytes types

• Variables and constants

let var1 = 1
let var2 = 0x123
const myaddr = addr"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAY5HFKQ"

• All binary and unary operations from TEAL

let a = (1 + 2) / 3
let b = ~a

• Functions

inline function sample1(a) {
    return a - 1
}

function sample2(a) {
    return a + 1
}

function noop() void {
    return
}

function logic() {
    return sample1(2) + sample2(3)
}

• Condition statements and expressions

function condition(a) {
    let b = if a == 1 { 10 } else { 0 }

    if b == 0 {
        return a
    }
    return 1
}

• Loops

let y= 2;
for y>0 { y=y-1 }

• Type checking

function get_string() {
    return "\x32\x33\x34"
}

function logic() {
    let a = 1
    a = get_string()  // <- type check error
    return a
}

• Accounts state access

function approval() {
    let x = accounts[1].Balance
    return 1
}

• Globals and txn data access

function logic() {
    let s = global.GroupSize
    let idx = 1
    let a = gtxn[s-1].ApplicationArgs[idx+2];
    return a != "\x01"
}

• Modules

import stdlib.const

• Antlr-based parser
• syntax highlighter for vscode.

Language guide

Check the language documentation!

Usage

• Tealang to bytecode

  tealang mycontract.tl -o mycontract.tok

• Tealang to TEAL

  tealang -c mycontract.tl -o mycontract.teal

• Tealang logic one-liner to bytecode

  tealang -l '(txn.Sender == "abc") && global.MinTxnFee > 2000' -o mycontract.tok

• stdin to stdout

  cat mycontract.tl | tealang -s -r - > mycontract.tok

• Dryrun / trace

  tealang -s -c -d '' examples/basic.tl

Build from sources

Prerequisites

1. Set up ANTLR4

   make antlr-install
   Refer to the documentation in case of problems.
2. Install runtime for Go

   go get -u github.com/antlr/antlr4/runtime/Go/antlr
3. Install and setup go-algorand

   make algorand-install
   Check the Algorand README for detailed build instructions if encounter any issues.

Build and test

make && make test

Optionally build and run Java AST visualizer

make java-gui ARGS=examples/basic.tl

Roadmap

1. Constant folding.
2. Improve errors reporting.
3. Code gen: do not use temp scratch in "assign and use" case.
4. Code gen: keep track scratch slots and mark as available after freeing with load.