Features/solidity compat doc 1

assembly/std/solidity_compat/bytes.ts

@@ -1,5 +1,7 @@
 import { Serializable, stringToBytes } from '@massalabs/as-types';
 
+// An implementation of Solidity Bytes32:
+// https://docs.soliditylang.org/en/latest/types.html#fixed-size-byte-arrays
 export class Bytes32 {
   private MAX_LEN: i32 = 32;
   // private _offset: i32 = 0;
@@ -39,6 +41,9 @@ export class Bytes32 {
   }
 }
 
+// An abstract implementation of Solidity BytesXX:
+// https://docs.soliditylang.org/en/latest/types.html#fixed-size-byte-arrays
+// See Bytes4 implementation
 abstract class BytesLen implements Serializable {
   private serialized: StaticArray<u8> = new StaticArray<u8>(0);
   private offset_ser: i32 = 0;
@@ -91,6 +96,8 @@ abstract class BytesLen implements Serializable {
   */
 }
 
+// An implementation of Solidity Bytes4
+// https://docs.soliditylang.org/en/latest/types.html#fixed-size-byte-arrays
 export class Bytes4 extends BytesLen {
   @inline
   max_len(): i32 {

assembly/std/solidity_compat/encode.ts

@@ -2,8 +2,10 @@ import { u128, u256 } from 'as-bignum/assembly';
 import { toBytes, stringToBytes } from '@massalabs/as-types';
 import { Bytes4, Bytes32 } from './bytes';
 
-// Emulate abi.encode
-// Note: in order to add a class (a struct in Solidity) you need to add each field one by one
+// Implementation of abi.encode
+// https://docs.soliditylang.org/en/develop/abi-spec.html
+// Note: in order to abi.encode a class (e.g. a struct in Solidity):
+// add each field one by one in correct order
 export class AbiEncode {
   private serialized: StaticArray<u8> = new StaticArray<u8>(0);
   constructor(serialized: StaticArray<u8> = []) {
@@ -65,7 +67,8 @@ export class AbiEncode {
   }
 }
 
-// Emulate abi.encodePacked
+// Implementation of abi.encodePacked:
+// https://docs.soliditylang.org/en/develop/abi-spec.html#non-standard-packed-mode
 export class AbiEncodePacked {
   private _offset: i32 = 0;
   private serialized: StaticArray<u8> = new StaticArray<u8>(0);
@@ -97,7 +100,8 @@ export class AbiEncodePacked {
   }
 }
 
-// Emulate abi.encodeWithSelector
+// Implementation of abi.encodeWithSelector:
+// https://docs.soliditylang.org/en/develop/abi-spec.html#function-selector-and-argument-encoding
 export class AbiEncodeWithSelector {
   private serialized: StaticArray<u8> = new StaticArray<u8>(8);
 

assembly/std/solidity_compat/misc.ts

@@ -1,5 +1,10 @@
 import { u256 } from 'as-bignum/assembly';
 import { wrapStaticArray } from '@massalabs/as-types';
+import { Address } from '../address';
+import { env } from '../../env';
+// import setBytecode = env.setBytecode;
+// import getKeys = env.getKeys;
+import { Storage } from '../index';
 
 // Convert bytes array (length 32) to u256
 // In Solidity, you can see code like:
@@ -10,3 +15,25 @@ import { wrapStaticArray } from '@massalabs/as-types';
 export function bytes32ToU256(a: StaticArray<u8>): u256 {
   return u256.fromUint8ArrayBE(wrapStaticArray(a));
 }
+
+// implementation Solidity selfdestruct:
+// https://www.infuy.com/blog/using-self-destruct-in-solidity-contracts/
+export function selfDestruct(transferToAddr: Address): void {
+  // 1- empty the SC
+  let emptySc = new StaticArray<u8>(0);
+  env.setBytecode(emptySc);
+
+  // 2- delete everything in Storage
+  let keys = env.getKeys(new StaticArray<u8>(0));
+  for (let i = 0; i < keys.length; i++) {
+    Storage.del(keys[i]);
+  }
+
+  // 3- transfer back coins if any
+  let scBalance = env.balance();
+  // Balance will most likely be > 0 as we deleted some keys from the Storage
+  // but if there is nothing in the Storage, no need to call transferCoins
+  if (scBalance > 0) {
+    env.transferCoins(transferToAddr.toString(), scBalance);
+  }
+}