Get started

Create a new directory and initialize npm:

$ mkdir helios_get_started
$ cd ./helios_get_started
$ npm init es6 -y

Install the compiler and utility libraries:

$ npm install @helios-lang/compiler @helios-lang/codec-utils @helios-lang/uplc

Create a file called validator.hl, with the following content:

spending redeemer_equals_datum

func main(datum: Int, redeemer: Int) -> () {
    assert(redeemer == datum, "redeemer not equal to datum")
}

Create a JS script called compile.js, with the following content:

import { readFileSync } from "node:fs"
import { bytesToHex } from "@helios-lang/codec-utils"
import { Program } from "@helios-lang/compiler"
import { makeIntData, makeUplcDataValue } from "@helios-lang/uplc"

// compile the validator
const src = readFileSync("./validator.hl").toString()
const program = new Program(src)
const uplc = program.compile()

// test with a dummy script context
const datum = makeUplcDataValue(makeIntData(0))
const redeemer = makeUplcDataValue(makeIntData(0))
const scriptContext = makeUplcDataValue(makeIntData(0))
const { result } = uplc.eval([datum, redeemer, scriptContext])

// check the return value
if ("right" in result) {
    if (result.right.kind != "unit") {
        throw new Error(`unexpected return value, expected '()' but got '${result.right.toString()}'`)
    }
} else {
    throw new Error(`evaluation failed: ${result.left.error}`)
}

// serialize the compiled validator
console.log(bytesToHex(uplc.toCbor()))

Run the script:

$ node ./compile.js
581c581a01000022233225333573466e1c00400852616375a0066eb40081

The printed output is the hex encoded bytecode of the validator.

Further reading​

Further reading