add cameligo contract

src/test/contracts/FA1.2.mligo

@@ -0,0 +1,109 @@
+type tokens = (address, nat) big_map
+type allowances = (address * address, nat) big_map (* (sender,account) -> value *)
+
+type storage = {
+  tokens      : tokens;
+  allowances  : allowances;
+  total_amount : nat;
+}
+
+type transfer = {
+	address_from : address;
+	address_to   : address;
+	value        : nat;
+}
+
+type approve = {
+	spender : address;
+	value   : nat;
+}
+
+type getAllowance = {
+	owner    : address;
+	spender  : address;
+	callback : nat contract;
+}
+
+type getBalance = {
+	owner    : address;
+	callback : nat contract;
+}
+
+type getTotalSupply = {
+	callback : nat contract;
+}
+
+type action =
+  	Transfer       of transfer
+|	Approve        of approve
+|	GetAllowance   of getAllowance
+|	GetBalance     of getBalance
+|	GetTotalSupply of getTotalSupply
+
+let transfer (p,s : transfer * storage) : operation list * storage =
+   let new_allowances =   
+		if Tezos.sender = p.address_from then s.allowances
+		else
+			let authorized_value = match Big_map.find_opt (Tezos.sender,p.address_from) s.allowances with
+				Some value -> value
+			|	None       -> 0n
+			in
+			if (authorized_value < p.value)
+			then (failwith "Not Enough Allowance" : allowances)
+			else Big_map.update (Tezos.sender,p.address_from) (Some (abs(authorized_value - p.value))) s.allowances
+   in    
+	let sender_balance = match Big_map.find_opt p.address_from s.tokens with
+		Some value -> value
+	|	None        -> 0n
+	in
+	if (sender_balance < p.value)
+	then (failwith "Not Enough Balance" : operation list * storage)
+	else
+		let new_tokens = Big_map.update p.address_from (Some (abs(sender_balance - p.value))) s.tokens in
+		let receiver_balance = match Big_map.find_opt p.address_to s.tokens with
+			Some value -> value
+		|	None        -> 0n
+		in
+		let new_tokens = Big_map.update p.address_to (Some (receiver_balance + p.value)) new_tokens in
+		([]:operation list), {s with tokens = new_tokens; allowances = new_allowances}
+
+let approve (p,s : approve * storage) : operation list * storage =
+	let previous_value = match Big_map.find_opt (p.spender, Tezos.sender) s.allowances with
+		Some value -> value
+	|	None -> 0n
+	in
+	if previous_value > 0n && p.value > 0n
+	then (failwith "Unsafe Allowance Change" : operation list * storage)
+	else
+		let new_allowances = Big_map.update (p.spender, Tezos.sender) (Some (p.value)) s.allowances in
+		([] : operation list), {s with allowances = new_allowances}
+
+let getAllowance (p,s : getAllowance * storage) : operation list * storage =
+	let value = match Big_map.find_opt (p.owner, p.spender) s.allowances with
+		Some value -> value
+	|	None -> 0n
+	in
+	let op = Tezos.transaction value 0mutez p.callback in
+	([op],s)
+
+let getBalance (p,s : getBalance * storage) : operation list * storage =
+	let value = match Big_map.find_opt p.owner s.tokens with
+		Some value -> value
+	|	None -> 0n
+	in
+	let op = Tezos.transaction value 0mutez p.callback in
+	([op],s)
+
+let getTotalSupply (p,s : getTotalSupply * storage) : operation list * storage =
+  let total = s.total_amount in
+  let op    = Tezos.transaction total 0mutez p.callback in
+  ([op],s)
+
+
+let main (a,s:action * storage) = 
+ 	match a with
+   	Transfer p -> transfer (p,s)
+	|	Approve  p -> approve (p,s)
+	|	GetAllowance p -> getAllowance (p,s)
+	|  GetBalance p -> getBalance (p,s)
+	|	GetTotalSupply p -> getTotalSupply (p,s)