fixed erc20 constructor and corrected test as appropriate

example/erc20/erc20_test.js

@@ -14,12 +14,11 @@ if (logSteps) {
 	});
 }
 
-async function init(caller_address, total_supply) {
-	const calldata = [{index: 0, value: new BN(total_supply), len: 32},];
-	const initialMemory = [], inputStack = [], callvalue = 0;
+async function init(caller_address) {
+	const initialMemory = [], inputStack = [], calldata = [], callvalue = 0;
 	const callerAddr = caller_address;
 	let data = await main(vm, 'ERC20', inputStack, initialMemory, calldata, callvalue, callerAddr);
-	console.log(`*** Initialised ERC20 with balance ${total_supply} at address 0x${caller_address.toString(16)}.`);
+	console.log(`*** Initialised ERC20 with tokens at address 0x${caller_address.toString(16)}.`);
 	if (showGasCost) {console.log(`Gas cost when executing macro = ${data.gas}.`);}
 }
 
@@ -93,19 +92,19 @@ async function transfer_from(caller_address, token_owner, recipient, amount) {
 /*
 Examples
 
-init(20, 1000); // Initialises ERC20 with 1000 tokens at address 20
-get_total_supply(); // Self-explanatory
+init(A); // Initialises ERC20 with all tokens at address A
+get_total_supply(); // Returns the number of tokens in circulation
 
-get_balance_of(20); // Gets balance at address 20
-transfer(20, 30, 100); // Transfers 100 tokens from 20 to 30
+get_balance_of(A); // Gets balance at address A
+transfer(A, B, 100); // Transfers 100 tokens from A to B
 
-get_allowance(20, 40); // Gets allowance given to 40 by 20
-approve(20, 40, 100); // Approves 100 of 20's tokens for 40
-transfer_from(20, 40, 50); // Transfers 50 of 20's tokens approved for 40 to 40
+get_allowance(A, C); // Gets allowance given to C by A
+approve(A, C, 100); // Approves 100 of A's tokens for C
+transfer_from(A, C, 50); // Transfers 50 of A's tokens approved for C to C
 */
 
 async function runMainLoop() {
-	await init(0xabba, 20000);
+	await init(0xabba);
 	await get_total_supply();
 
 	await transfer(0xabba, 0xade1e, 1000);

example/erc20/huff_modules/erc20.huff

@@ -1,5 +1,3 @@
-
-
 #define macro BALANCE_LOCATION = takes(0) returns(1) {
 	0x00 // do not change!
 }
@@ -8,26 +6,12 @@
 	0x01
 }
 
-#define macro SUPPLY_LOCATION = takes(0) returns(1) {
-	0x02
-}
-
 #define macro ALLOWANCE_LOCATION = takes(0) returns(1) {
-	0x03
-}
-
-template <error_location>
-#define macro MATH__ADD = takes(2) returns(1) {
-	dup2 add      // (a+b) b
-	dup1 swap2 gt // (b > (a+b)) (a+b)
-	<error_location> jumpi
+	0x02
 }
 
-template <error_location>
-#define macro MATH__SUB = takes(2) returns(1) {
-	dup1 dup3 gt // (b>a) a b
-	<error_location> jumpi
-	sub
+#define macro SUPPLY = takes(0) returns(1) {
+	0x19000000000 // ~1.7 trillion
 }
 
 #define macro ADDRESS_MASK = takes(1) returns(1) {
@@ -55,15 +39,20 @@ template <error_location>
 }
 
 #define macro ERC20 = takes(0) returns(0) {
-	// 1. store the total_supply value
-	0x00 calldataload dup1 SUPPLY_LOCATION() sstore
+	// 1. load transfer event arguments
+	caller 0 TRANSFER_EVENT_SIGNATURE() 0x20 0x00 SUPPLY()
+	// stack: total_supply 0x00 0x20 signature from to
 	// 2. store the owner's address
-	caller dup1 OWNER_LOCATION() sstore
-	// stack: caller total_supply
+	caller OWNER_LOCATION() sstore
+	// stack: total_supply 0x00 0x20 signature from to
 	// 3. give the owner a balance with value total_supply
-	0x00 mstore
-	0x40 0x00 sha3 // key(caller balance) total_supply
+	dup1
+	caller 0x00 mstore
+	0x40 0x00 sha3 // key(balances[caller]) total_supply total_supply 0x00 0x20 signature from to
 	sstore
+	// stack: value 0x00 0x20 signature from to
+	// 4. emit Transfer event
+	0x00 mstore log3
 }
 
 template <transfer, transfer_from, balance_of, allowance, approve, total_supply>
@@ -238,7 +227,7 @@ template <error_location>
 }
 
 #define macro ERC20__TOTAL_SUPPLY = takes(0) returns(0) {
-	SUPPLY_LOCATION() sload
+	SUPPLY()
 	0x00 mstore
 	0x20 0x00 return
 }