cryptcoin-junkey/README.md

## README.md

      
    Raw
  

              README.md
            
          
    これ is 何 ?

構想中の Monaparty スマコンでレンディングのプラットフォームが作れるかどうかの思考実験。処理系は、まだ無い。当然。
前提知識

Monaparty スマコンでは、誰かが投げた Monaparty メッセージにより発火が起こる。
発火のあと、契約内容のチェックが走る。検証用言語は BitcoinCash 版 Script からの独自拡張。
契約が成立すると、Monaparty メッセージを投げられる。メッセージは事前に埋め込んでもいいし、検証用言語を使って動的に作っても良い。
コントラクトは、一つの Monacoin アドレスにつき複数デプロイできる。
同一の TxIndex であっても、条件さえ合致すれば、同じ Moancoin アドレスにデプロイされた複数のコントラクトが発火される。
(下記シナリオでは xmp2monana と clone-mona2xmp が同じ TxIndex で実行されている)
思考実験のシナリオ

登場人物


"MSourceAddress" 借り手
"MDestinationAddress" 貸し手。スマコン。
"MONANA" 貸し出されるアセット
"XMP" 担保アセット

初期条件

下記擬似コードから生成されたコントラクト monana2xmp xmp2monana clone-xmp2monana が "MDestinationAddress" からデプロイされている。
貸し出し

"MSourceAddress" は、"MONANA" を借りるため、担保となる "XMP" を "MDestinationAddress" へ send する。
まず、コントラクト xmp2monana が発火。パラメータのチェックを行ったあと、"MSourceAddress" へ "MONANA" を send する (貸し出す)。
返却のための準備

次に、コントラクト clone-monana2xmp が発火。パラメータのチェックを行った後、monana2xmp のクローンを作成。
このクローンには、"MSourceAddress" がコントラクト実行時の初期スタックとして設定される。
返却

"MSourceAddress" は返却を行うため、"MONANA" を "MDestinationAddress" へ send する。
クローンされた monana2xmp が発火。下記条件を満たす場合に、"XMP" を "MDestinationAddress" へ send する。

返却期日を過ぎていない。
クローン時に埋め込まれたアドレス (コード例では "EmbeddedAddress" ) と "MSourceAddress" が一致する。
自分宛ての send である。
貸し出したアセットが送られてきている。
利息分を差し引いても残高がある。

上記条件を満たさない場合、コントラクトは "XMP" を send しない(無視する)。
結論


先日の検討 には無かった、"コントラクトのクローン" という機能が要る。
クローン自体は実装が難しいものではない。オブジェクト指向的に正しいものでもあり、導入には前向き。
構想の初期段階でここまで記述可能になるとは。これ意外と DeFi できてしまっているのでは?
2017 年くらいから断続的ながらも考え続けてきたことなので、当然と言えは当然でもある。


## clone-monana2xmp.mpascript
contract: {
  majorVersion: 1,
  minorVersion: 0,
  triggerType: send;
  // stack is [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, "memo" ]
  script: [
    // Address check.
    3,
    OP_PICK,        // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, "memo", "MDestinationAddress" ]
    OPX_MYADDRESS,  // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, "memo", "MDestinationAddress", "MDestinationAddress" ]
    OP_EQUALVERIFY, // Fail if the destination address is not me.
    // Drop memo.
    OP_DROP,  // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000 ]
    // Asset check.
    OP_SWAP,        // result: [ "MSourceAddress", "MDestinationAddress", 1000, "XMP" ]
    "XMP",          // result: [ "MSourceAddress", "MDestinationAddress", 1000, "XMP", "XMP" ]
    OP_EQUALVERIFY, // result: [ "MSourceAddress", "MDestinationAddress", 1000 ] or fail
    // Build contract message.
    OP_2DROP,         // result: [ "MSourceAddress" ]
    1, 2, 1234, OP_5, // result: [ "MSourceAddress", 1, 2, 0, 1234, OP_5 ] // pseodo. building contract clone message.
    OPX_BUILDMESSAGE, // result: [ ]
    OP_1              // result: [ OP_1 ] // means success.
  message: {} // will be built on the script.
}

## monana2xmp.mpascript
contract: {
  majorVersion: 1,
  minorVersion: 0,
  triggerType: send;
  // stack is [ "EmbeddedAddress" "MSourceAddress", "MDestinationAddress", "MONANA", 1000, "memo" ]
  // "EmbeddedAddress" was stored in the contract itself by "clone" contract.
  script: [
    // Return period check.
    0,
    OPX_CURRENTBLOCK, // result: [ ..., 0, 100 ]
    OPX_BEGINBLOCK,   // result: [ ..., 0, 100, 10 ]
    130,              // result: [ ..., 0, 100, 10, 130 ] // period
    OP_ADD, OP_SUB,   // result: [ ..., 0, -40 ]
    OP_GREATERTHAN,   // result: [ ..., OP_1 ]
    OP_VERIFY         // result: [ ... ] or fail

    // Source address check.
    5, 4,
    OP_PICK, OP_PICK, // result [ "EmbeddedAddress", "MSourceAddress", "MDestinationAddress", "MONANA", 1000, "memo", "EmbeddedAddress", "MSourceAddress" ]
    OP_EQUALVERIFY,   // result: [ "EmbeddedAddress", "MSourceAddress", "MDestinationAddress", "MONANA", 1000, "memo" ] or fail
    //// "EmbeddedAddress" can be ignored in following results.

    // Destination address check.
    3,
    OP_PICK,          // result: [ "MSourceAddress", "MDestinationAddress", "MONANA", 1000, "memo", "MDestinationAddress" ]
    OPX_MYADDRESS,    // result: [ "MSourceAddress", "MDestinationAddress", "MONANA", 1000, "memo", "MDestinationAddress", "MDestinationAddress" ]
    OP_EQUALVERIFY,   // Fail if the destination address is not me.
    OP_DROP,          // result: [ "MSourceAddress", "MDestinationAddress", "MONANA", 1000 ]

    // Asset check
    OP_SWAP,  // result: [ "MSourceAddress", "MDestinationAddress", 1000, "MONANA" ]
    "MONANA", // result: [ "MSourceAddress", "MDestinationAddress", 1000, "MONANA", "MONANA" ]
    OP_EQUALVERIFY, // result: [ "MSourceAddress", "MDestinationAddress", 1000 ] or fail

// Return "XMP"
    "XMP",   // result: [ "MSourceAddress", "MDestinationAddress", 1000, "XMP" ]
    OP_SWAP, // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000 ]

    // Decrease. Take interest. (the logic is an example. Should be redesigned.)
    OPX_CURRENTBLOCK, // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, 100 ]
    OPX_BEGINBLOCK,   // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, 100, 10 ]
    OP_NEGATE,        // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, 100, -10 ]
    OP_ADD,           // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, 90 ]
    OP_NEGATE,        // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, -90 ]
    OP_ADD,           // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 990 ]

    // Balance check.
    OP_DUP,         // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 990, 990 ]
    0,              // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 990, 990, 0 ]
    OP_GRATERTHAN,  // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 990, OP_1 ]
    OP_EQUALVERIFY, // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 990, OP_1 ] or fail

    // Build message
    "MONANA"  // result: [ "MSourceAddress", "MDestinationAddress",  1000, "XMP" ]
    OP_SWAP,  // result: [ "MSourceAddress", "MDestinationAddress",  "XMP", 1000 ]
    OP_2SWAP, // result: [ "XMP", 1000, "MSourceAddress", "MDestinationAddress" ]
    OP_SWAP,  // result: [ "XMP", 1000, "MDestinationAddress", "MSourceAddress" ]
    OP_2SWAP, // result: [ "MDestinationAddress", "MSourceAddress", "XMP", 1000 ]
    OP_1,     // result: [ "MDestinationAddress", "MSourceAddress", "XMP", 1000, OP_1 ] // OP_1 means "send"
    OPX_BUILDMESSAGE, // result [ ]

    OP_1      // result: [ OP_1 ] // means success.
  ],
  message: {} // will be built on the script.
}

## xmp2monana.mpascript
contract: {
  majorVersion: 1,
  minorVersion: 0,
  triggerType: send;
  // stack is [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, "memo" ]
  script: [
    // Address check.
    3,
    OP_PICK,  // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, "memo", "MDestinationAddress" ]
    OPX_MYADDRESS, // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, "memo", "MDestinationAddress", "MDestinationAddress" ]
    OP_EQUALVERIFY, // Fail if the destination address is not me.
    OP_DROP,   // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000 ]

    // Asset check.
    OP_SWAP,   // result: [ "MSourceAddress", "MDestinationAddress", 1000, "XMP" ]
    "XMP",     // result: [ "MSourceAddress", "MDestinationAddress", 1000, "XMP", "XMP" ]
    OP_EQUALVERIFY, // result: [ "MSourceAddress", "MDestinationAddress", 1000 ] or fail

    // Build message
    "MONANA"  // result: [ "MSourceAddress", "MDestinationAddress",  1000, "MONANA" ]
    OP_SWAP,  // result: [ "MSourceAddress", "MDestinationAddress",  "MONANA", 1000 ]
    OP_2SWAP, // result: [ "MONANA", 1000, "MSourceAddress", "MDestinationAddress" ]
    OP_SWAP,  // result: [ "MONANA", 1000, "MDestinationAddress", "MSourceAddress" ]
    OP_2SWAP, // result: [ "MDestinationAddress", "MSourceAddress", "MONANA", 1000 ]
    OP_1,     // result: [ "MDestinationAddress", "MSourceAddress", "MONANA", 1000, OP_1 ] // OP_1 means "send"
    OPX_BUILDMESSAGE, // result [ ] // "send" message is built and stored.

    OP_1      // result: [ OP_1 ] // means success.
  ],
  message: {} // will be built on the script.
}
	contract: {
	majorVersion: 1,
	minorVersion: 0,
	triggerType: send;
	// stack is [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, "memo" ]
	script: [
	// Address check.
	3,
	OP_PICK, // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, "memo", "MDestinationAddress" ]
	OPX_MYADDRESS, // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000, "memo", "MDestinationAddress", "MDestinationAddress" ]
	OP_EQUALVERIFY, // Fail if the destination address is not me.
	// Drop memo.
	OP_DROP, // result: [ "MSourceAddress", "MDestinationAddress", "XMP", 1000 ]
	// Asset check.
	OP_SWAP, // result: [ "MSourceAddress", "MDestinationAddress", 1000, "XMP" ]
	"XMP", // result: [ "MSourceAddress", "MDestinationAddress", 1000, "XMP", "XMP" ]
	OP_EQUALVERIFY, // result: [ "MSourceAddress", "MDestinationAddress", 1000 ] or fail
	// Build contract message.
	OP_2DROP, // result: [ "MSourceAddress" ]
	1, 2, 1234, OP_5, // result: [ "MSourceAddress", 1, 2, 0, 1234, OP_5 ] // pseodo. building contract clone message.
	OPX_BUILDMESSAGE, // result: [ ]
	OP_1 // result: [ OP_1 ] // means success.
	message: {} // will be built on the script.
	}