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Building a generalized encoder for assembly script

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Serial-as

serial-as simplifies creating serialized encoders/decoders for the assemblyscript language. Furthermore, it readily implements a JSON, and a Borsh (de)serializer.

Installing and Testing

yarn install
yarn test

What is a Serializer

A (de)Serialized is an object that encodes/decodes objects into a predefined type. For example, the JSON serializer encodes objects into strings, and decodes JSON-encoded strings into objects.

How to create a Serializer

Extend the classes Serializer and Deserealizer exported by serial-as and implement their methods. Then, use your Serializer and Deserealizer to instantiate a Serial object. For example, to create a serializer that encodes/decodes objects into encoded strings you will write the following code.

import { Serializer, Deserializer } from "@serial-as/core";

class MySerializer extends Serializer<string>{
  /* implement methods to convert types into string */
}

class MyDeserializer extends Deserializer<string>{
  /* implement methods to parse a string into an object */
}

export class MySerial<string, MySerializer, MyDeserializer> { }

In order to implement MyDeserializer you will need to implement the abstract methods of the Deserializer class. Among others, you must implement

  • decode_bool():bool
  • abstract decode_map<K, V>():Map<K, V>
  • decode_string():string
  • decode_i32():i32
  • etc.

You can use as examples the Borsh and JSON serializers included in this repository. Simply copy one of the folders, and change the methods implemented on them.

How to use your (De)Serializer

In order for an object to be serializable you need to decorate it with the @serializable tag. After this, the object can be used with any Serial object.

@serializable
class Pair{
  x: i32 = 0,
  y: i32 = 0
}

let pair:Pair = {x:1, y:2}

// Pair can also be used with your implemented serializer
const myserial:MySerial = new MySerial()

// serialize the object into a string
let serialized:string = myserial.serialize(object)  

// decoded must be the Pair = {x:1, y:2}
let decoded:Pair = myserial.deserialize<Pair>(serialized)

Once more, you can use the Borsh and JSON implementation included in this repository as a guide.

Under the Hood

Under the hood, serial-as implements a transform to visit @serializable objects and encode/decode their fields. To do so, the transform uses the methods implemented in the Serializer/Deserializer classes.