Add require builtin

test/contracts/aeproof.aes

@@ -104,10 +104,10 @@ contract AEProof =
                      proofsByOwner : map(address, array(uint)) }
 
     function notarize(document:string, comment:string, ipfsHash:hash) =
-        let _ = require(aetoken.balanceOf(caller()) > 0)
+        let _ = require(aetoken.balanceOf(caller()) > 0, "false")
         let proofHash: uint = calculateHash(document)
         let proof : proof = Map.get_(proofHash, state().proofs)
-        let _ = require(proof.owner == #0)
+        let _ = require(proof.owner == #0, "false")
         let proof' : proof = proof { owner = caller()
                                    , timestamp = block().timestamp
                                    , proofBlock = block().height
@@ -124,12 +124,12 @@ contract AEProof =
     function getProof(document) : proof =
         let calcHash = calculateHash(document)
         let proof = Map.get_(calcHash, state().proofs)
-        let _ = require(proof.owner != #0)
+        let _ = require(proof.owner != #0, "false")
         proof
 
     function getProofByHash(hash: uint) : proof =
         let proof = Map.get_(hash, state().proofs)
-        let _ = require(proof.owner != #0)
+        let _ = require(proof.owner != #0, "false")
         proof
 
 
@@ -141,5 +141,3 @@ contract AEProof =
     function getProofsByOwner(owner: address): array(uint) =
         Map.get(owner, state())
 
-    function require(x : bool) : unit = if(x) () else abort("false")
-

test/contracts/basic_auth.aes

@@ -15,5 +15,3 @@ contract BasicAuth =
   function to_sign(h : hash, n : int) =
     Crypto.blake2b((h, n))
 
-  private function require(b : bool, err : string) =
-    if(!b) abort(err)

test/contracts/bitcoin_auth.aes

@@ -14,5 +14,3 @@ contract BitcoinAuth =
   function to_sign(h : hash, n : int) : hash =
     Crypto.blake2b((h, n))
 
-  private function require(b : bool, err : string) =
-    if(!b) abort(err)

test/contracts/dutch_auction.aes

@@ -15,9 +15,6 @@ contract DutchAuction =
     Chain.spend(to, amount)
     total - amount
 
-  private function require(b : bool, err : string) =
-    if(!b) abort(err)
-
   // TTL set by user on posting contract, typically (start - end ) div dec
   public function init(beneficiary, start, decrease) : state =
     require(start > 0 && decrease > 0, "bad args")

test/contracts/erc20_token.aes

@@ -77,9 +77,6 @@ contract ERC20Token =
     put( state{approval_log = e :: state.approval_log })
     e
 
-  private function require(b : bool, err : string) =
-    if(!b) abort(err)
-
   private function sub(_a : int, _b : int) : int =
     require(_b =< _a, "Error")
     _a - _b

test/contracts/fundme.aes

@@ -12,9 +12,6 @@ contract FundMe =
                    deadline      : int,
                    goal          : int }
 
-  private function require(b : bool, err : string) =
-    if(!b) abort(err)
-
   private stateful function spend(args : spend_args) =
     Chain.spend(args.recipient, args.amount)
 

test/contracts/oracles.aes

@@ -108,5 +108,3 @@ contract Oracles =
     Oracle.respond(o, q, Answer(question, "magic", 1337), signature = sig)
     Oracle.get_answer(o, q)
 
-  private function require(b : bool, err : string) =
-    if(!b) abort(err)

test/contracts/oracles_gas.aes

@@ -20,5 +20,3 @@ contract OraclesGas =
     Oracle.respond(o, q, answer)
     ()
 
-  private function require(b : bool, err : string) =
-    if(!b) abort(err)

test/contracts/oracles_no_vm.aes

@@ -33,5 +33,3 @@ contract Oracles =
                      q : query_id) : option(answer_t) =
     Oracle.get_answer(o, q)
 
-  private function require(b : bool, err : string) =
-    if(!b) abort(err)

test/contracts/variant_types.aes

@@ -9,8 +9,6 @@ contract VariantTypes =
 
   function init() = Stopped
 
-  function require(b) = if(!b) abort("required")
-
   stateful function start(bal : int) =
     switch(state)
       Stopped => put(Started({owner = Call.caller, balance = bal, color = Grey(0)}))
@@ -18,7 +16,7 @@ contract VariantTypes =
   stateful function stop() =
     switch(state)
       Started(st) =>
-        require(Call.caller == st.owner)
+        require(Call.caller == st.owner, "required")
         put(Stopped)
         st.balance