Smart Contract Details

[{"name":"SC_ACTION","datatype":"U","value":1},{"name":"SC_CODE","datatype":"S","value":"\n//          .-.\n//         (o o) \n//         | O \\  boo!\n//         |    \\\n//         '~~~~'\n//    ?\n//   /\\                ___\n//  (oo)              |RIP|\n//  /||\\              |___|\n//////////////////////////////////////\n// Ghost Exchange v1.1\n// Use at your own risk\n// For more info visit: ghost.trading\n//////////////////////////////////////\n\nFunction Initialize() Uint64\n    10 STORE(\"owner\", SIGNER())\n    20 STORE(\"feeTo\", SIGNER())\n    30 STORE(\"nameHdr\", \"Ghost Exchange\")\n    40 STORE(\"descrHdr\", \"Phantom-powered finance\") \n    50  RETURN 0\nEnd Function \n\n// Provided liquidity will be tracked using BOO tokens. \n// BOO TOKENS ARE NOT ASSETS. Each account's BOO balance per token pair is stored \n// inside the Smart Contract as a variable with the following schema:\n// \u003cprovider_address\u003e:BOO:\u003casset_address\u003e\n// The total liquidity provided by all LPs of a pair at a given moment is denominated supply.\n// supply is tracked inside the Smart Contract as a variable with the following schema:\n// \u003casset_address\u003e:BOO\n// Deposit assets and DERO at current ratio to get BOO tokens. \n// {asset_address} The deposited asset's SCID\n// {min_liquidity} Minimum number of BOO sender will get if total BOO supply is greater than 0.\n// {min_liquidity} does nothing when total BOO supply is 0.\nFunction AddLiquidity(asset_address String, min_liquidity Uint64) Uint64\n    01 DIM total_liquidity, dero_reserve, asset_reserve, asset_amount, liquidity_minted, dero_deposited, asset_deposited, SYS_MAX_VALUE as Uint64\n    02 LET SYS_MAX_VALUE = 18446744073709551 // Uint64.Max/1000 to protect from infinite supply tokens\n    03 LET dero_deposited = DEROVALUE()\n    04 LET asset_deposited = ASSETVALUE(HEXDECODE(asset_address))\n    10 IF (asset_deposited \u003e 0 \u0026 dero_deposited \u003e 0 ) THEN GOTO 30\n    20 GOTO 666\n    30 LET total_liquidity =  get_supply_per_asset(asset_address) \n    // Pair already exists\n    40 IF total_liquidity \u003e 0 THEN GOTO 41 ELSE GOTO 60\n        41 IF min_liquidity \u003e 0 THEN GOTO 43\n        42 GOTO 666  \n        43 LET dero_reserve = get_dero_reserve_per_asset(asset_address) \n        44 LET asset_reserve = get_asset_reserve(asset_address)\n        45 IF will_addition_overflow(asset_reserve, asset_deposited) == 1 THEN GOTO 666\n        46 mintFee(dero_reserve, asset_reserve, asset_address)\n        47 LET total_liquidity = get_supply_per_asset(asset_address) // Must be defined again since totalSupply can update in mintFee\n        48 LET asset_amount =   mult_div(dero_deposited, asset_reserve , dero_reserve + 1)\n        49 LET liquidity_minted = mult_div(dero_deposited, total_liquidity, dero_reserve)\n        50 IF asset_deposited \u003e= asset_amount \u0026 liquidity_minted \u003e= min_liquidity \u0026 (asset_reserve + asset_deposited \u003c= SYS_MAX_VALUE) THEN GOTO 52\n        51 GOTO 666\n        52 increase_provider_liquidity_by(SIGNER(), liquidity_minted, asset_address) \n        53 set_supply_per_asset(total_liquidity + liquidity_minted, asset_address)\n        54 IF asset_deposited == asset_amount THEN GOTO 56\n        // Return any reminding assets\n        55 SEND_ASSET_TO_ADDRESS(SIGNER(), asset_deposited - asset_amount, HEXDECODE(asset_address))\n        // Increase the dero reserve record for this asset\n        56 set_dero_reserve_per_asset(dero_reserve + dero_deposited, asset_address)\n        // Increase the asset reserve record\n        57 set_asset_reserve(asset_reserve + asset_amount, asset_address)\n        58 STORE(asset_address+\":rootKLast\",  sqrt(dero_reserve + dero_deposited) * sqrt(asset_reserve + asset_amount))\n        // Return gracefully\n        59 GOTO 70\n    // else\n    // Creating pair  \n    60 IF dero_deposited \u003e= 1000 \u0026 asset_deposited \u003c= SYS_MAX_VALUE THEN GOTO 62\n        61 GOTO 666\n        // Initialize the asset reserve record for this asset\n        62 set_asset_reserve(asset_deposited, asset_address)\n        63 DIM initial_liquidity as Uint64\n        64 LET initial_liquidity = dero_deposited\n        65 set_supply_per_asset(initial_liquidity, asset_address)\n        // Initialize the dero reserve record for this asset\n        66 set_dero_reserve_per_asset(dero_deposited, asset_address)\n        67 STORE(asset_address+\":rootKLast\", sqrt(asset_deposited) * sqrt(dero_deposited))\n        68 increase_provider_liquidity_by(SIGNER(), initial_liquidity, asset_address)\n    70 RETURN 0\n\n    666 RETURN 1\nEnd Function\n\n// Burn BOO tokens to withdraw Dero \u0026 assets at current ratio.\n// {amount} Amount of BOO burned.\n// {min_dero} Minimum DERO withdrawn.\n// {min_assets} Minimum assets withdrawn.\n// {asset_address} The deposited asset's SCID\nFunction RemoveLiquidity(amount Uint64, min_dero Uint64, min_assets Uint64, asset_address String) Uint64\n    01  DIM total_liquidity, dero_reserve, asset_reserve, dero_amount, asset_amount as Uint64\n    10  IF amount \u003e 0  \u0026 (min_dero \u003e 0 \u0026 min_assets \u003e 0) \u0026 ( get_provider_liquidity(SIGNER(), asset_address) \u003e= amount ) THEN GOTO 30\n    20  GOTO 666\n    30  LET total_liquidity = get_supply_per_asset(asset_address)\n    40  IF total_liquidity \u003e 0 THEN GOTO 60\n    50  GOTO 666\n    60  LET asset_reserve = get_asset_reserve(asset_address)\n    70  LET dero_reserve = get_dero_reserve_per_asset(asset_address)\n    80  mintFee(dero_reserve, asset_reserve, asset_address)\n    90  LET total_liquidity = get_supply_per_asset(asset_address) // Must be defined again since totalSupply can update in mintFee\n   100  LET dero_amount  = mult_div(amount, dero_reserve, total_liquidity)\n   110  LET asset_amount = mult_div(amount, asset_reserve, total_liquidity)\n   120  IF dero_amount \u003e= min_dero \u0026 asset_amount \u003e= min_assets THEN GOTO 140\n   130  GOTO 666\n   140  decrease_provider_liquidity_by(SIGNER(), amount, asset_address)\n   150  set_supply_per_asset(total_liquidity - amount, asset_address)\n   160  set_dero_reserve_per_asset(dero_reserve - dero_amount, asset_address)\n   170  set_asset_reserve(asset_reserve - asset_amount, asset_address)\n   180  STORE(asset_address+\":rootKLast\", sqrt(dero_reserve - dero_amount) * sqrt(asset_reserve - asset_amount) )\n   190  SEND_DERO_TO_ADDRESS(SIGNER(), dero_amount)\n   200  SEND_ASSET_TO_ADDRESS(SIGNER(),asset_amount, HEXDECODE(asset_address))\n   210  RETURN 0\n\n   666  RETURN 1\nEnd Function\n\n// Pricing function for converting between DERO \u0026 Assets.\n// {input_amount} Amount of DERO or Assets being sold.\n// {input_reserve} Amount of DERO or Assets (input type) in exchange reserves.\n// {output_reserve} Amount of DERO or Assets (output type) in exchange reserves.\nFunction getInputPrice(input_amount Uint64, input_reserve Uint64, output_reserve Uint64) Uint64\n    01 DIM SYS_MAX_VALUE as Uint64\n    02 LET SYS_MAX_VALUE = 18446744073709551\n    10 IF input_reserve \u003e 0 \u0026 output_reserve \u003e 0 \u0026 input_amount \u003c= SYS_MAX_VALUE THEN GOTO 30\n    20 PANIC\n    30 DIM input_amount_with_fee as Uint64\n    40 LET input_amount_with_fee = input_amount * 997\n    50 IF will_addition_overflow(input_reserve * 1000, input_amount * 1000) == 0 THEN GOTO 70\n    60 PANIC // Infinite supply token attack\n    70 RETURN mult_div(input_amount_with_fee, output_reserve, (input_reserve * 1000) + input_amount_with_fee)\nEnd Function\n\n// Pricing function for converting between DERO \u0026 Assets.\n// {output_amount} Amount of DERO or Assets being bought.\n// {input_reserve} Amount of DERO or Assets (input type) in exchange reserves.\n// {output_reserve} Amount of DERO or Assets (output type) in exchange reserves.\nFunction getOutputPrice(output_amount Uint64, input_reserve Uint64, output_reserve Uint64) Uint64\n    10 IF input_reserve \u003e 0 \u0026\u0026 output_reserve \u003e 0 \u0026\u0026 output_reserve \u003e output_amount THEN GOTO 30\n    20 PANIC\n    30 RETURN mult_div(input_reserve * 1000, output_amount, (output_reserve - output_amount) * 997 + 1)\nEnd Function\n\nFunction deroToAssetInput(dero_sold Uint64, min_assets Uint64, asset_address String) Uint64\n    10 IF  (dero_sold \u003e 0 \u0026 min_assets \u003e 0) THEN GOTO 30\n    20 PANIC\n    30 DIM assets_bought, asset_reserve, dero_reserve as Uint64\n    40 LET asset_reserve = get_asset_reserve(asset_address)\n    50 LET dero_reserve = get_dero_reserve_per_asset(asset_address)\n    60 LET assets_bought = getInputPrice(dero_sold, dero_reserve, asset_reserve)\n    70 IF assets_bought \u003e= min_assets THEN GOTO 90\n    80 PANIC\n    90 SEND_ASSET_TO_ADDRESS(SIGNER(), assets_bought, HEXDECODE(asset_address))\n   100 set_asset_reserve(asset_reserve - assets_bought, asset_address)\n   110 set_dero_reserve_per_asset(dero_reserve + dero_sold, asset_address)\n   120 RETURN 0\nEnd Function\n\n// Convert DERO to Assets.\n// User specifies exact input (DEROVALUE()).\n// User cannot specify minimum output.\n// {asset_address} Address of the asset to trade.\nFunction DeroToAssetSwapInput(asset_address String) Uint64\n    10 RETURN deroToAssetInput(DEROVALUE(), 1, asset_address)\nEnd Function\n\n// Convert DERO to Assets.\n// User specifies exact input (DEROVALUE()) \u0026 minimum output.\n// {min_assets} Minimum Assets bought.\n// {asset_address} Address of the asset to trade.\nFunction DeroToAssetSwapInputMin(min_assets Uint64, asset_address String) Uint64\n    10 RETURN deroToAssetInput(DEROVALUE(), min_assets, asset_address)\nEnd Function\n\nFunction deroToAssetOutput(assets_bought Uint64, max_dero Uint64, asset_address String) Uint64\n    10 IF (assets_bought \u003e 0 \u0026 max_dero \u003e 0) THEN GOTO 30\n    20 PANIC\n    30 DIM asset_reserve, dero_reserve, dero_sold, dero_refund as Uint64\n    40 LET asset_reserve = get_asset_reserve(asset_address)\n    41 LET dero_reserve = get_dero_reserve_per_asset(asset_address)\n    50 LET dero_sold = getOutputPrice(assets_bought, dero_reserve, asset_reserve)\n    60 IF dero_sold \u003e max_dero THEN GOTO 61 ELSE GOTO 70\n    61 PANIC\n    70 LET dero_refund = max_dero - dero_sold\n    80 IF dero_refund == 0 THEN GOTO 100\n    90 SEND_DERO_TO_ADDRESS(SIGNER(), dero_refund)\n   100 SEND_ASSET_TO_ADDRESS(SIGNER(), assets_bought, HEXDECODE(asset_address))\n   110 set_asset_reserve(asset_reserve - assets_bought, asset_address)\n   120 set_dero_reserve_per_asset(dero_reserve + dero_sold, asset_address)\n   130 RETURN 0\nEnd Function\n\n// Convert DERO to Assets.\n// User specifies maximum input (DEROVALUE()) \u0026 exact output.\n// {assets_bought} Amount of Assets bought.\n// {asset_address} Address of the asset to trade.\nFunction DeroToAssetSwapOutput(assets_bought Uint64, asset_address String) Uint64\n    10 RETURN deroToAssetOutput(assets_bought, DEROVALUE(), asset_address)\nEnd Function\n\nFunction assetToDeroInput(assets_sold Uint64, min_dero Uint64, asset_address String) Uint64\n    10 IF (assets_sold \u003e 0 \u0026 min_dero \u003e 0) THEN GOTO 30\n    20 PANIC\n    30 DIM asset_reserve, dero_bought as Uint64\n    40 LET asset_reserve = get_asset_reserve(asset_address)\n    50 LET dero_bought = getInputPrice(assets_sold, asset_reserve, get_dero_reserve_per_asset(asset_address))\n    60 IF dero_bought \u003e= min_dero THEN GOTO 80\n    70 PANIC\n    80 SEND_DERO_TO_ADDRESS(SIGNER(),dero_bought)\n    90 set_dero_reserve_per_asset(get_dero_reserve_per_asset(asset_address) - dero_bought, asset_address)\n   100 set_asset_reserve(asset_reserve + assets_sold, asset_address)\n   110 RETURN 0\nEnd Function\n\n// Convert Assets to DERO.\n// User specifies exact input (ASSETVALUE(asset_address)) \u0026 minimum output.\n// {min_dero} Minimum DERO purchased.\n// {asset_address} Address of the asset to trade.\nFunction AssetToDeroSwapInput(min_dero Uint64, asset_address String) Uint64\n    10 RETURN assetToDeroInput(ASSETVALUE(HEXDECODE(asset_address)), min_dero, asset_address)\nEnd Function\n\n\nFunction assetToDeroOutput(dero_bought Uint64, max_assets Uint64 , asset_address String) Uint64\n    10 IF  dero_bought \u003e 0 THEN GOTO 30\n    20 PANIC\n    30 DIM asset_reserve, assets_sold, asset_refund as Uint64\n    40 LET asset_reserve = get_asset_reserve(asset_address)\n    50 LET assets_sold = getOutputPrice(dero_bought, asset_reserve, get_dero_reserve_per_asset(asset_address))\n    // assets_sold is always \u003e zero\n    60 IF max_assets \u003e= assets_sold THEN GOTO 80\n    70 PANIC\n    80 SEND_DERO_TO_ADDRESS(SIGNER(), dero_bought)\n    90 LET asset_refund = max_assets - assets_sold\n   100 IF asset_refund == 0 THEN GOTO 120\n   110 SEND_ASSET_TO_ADDRESS(SIGNER(), asset_refund, HEXDECODE(asset_address))\n   120 set_dero_reserve_per_asset(get_dero_reserve_per_asset(asset_address) - dero_bought, asset_address)\n   130 set_asset_reserve(asset_reserve + assets_sold, asset_address)\n   140 RETURN 0\nEnd Function\n\n// Convert Assets to DERO.\n// User specifies maximum input (ASSETVALUE(asset_address)) \u0026 exact output.\n// {dero_bought} Amount of DERO purchased.\n// {asset_address} Address of the asset to trade.\nFunction AssetToDeroSwapOutput(dero_bought Uint64, asset_address String) Uint64\n    10 RETURN assetToDeroOutput(dero_bought, ASSETVALUE(HEXDECODE(asset_address)), asset_address)\nEnd Function\n\n// Public price function for DERO to Asset trades with an exact input.\n// {dero_sold} Amount of DERO sold.\n// {asset_address} Address of the asset to trade.\n// @returns Amount of Assets that can be bought with input DERO.\nFunction GetDeroToAssetInputPrice(dero_sold Uint64, asset_address String) Uint64\n    10 IF dero_sold \u003e 0 THEN GOTO 30\n    20 RETURN 0\n    30 RETURN getInputPrice(dero_sold, get_dero_reserve_per_asset(asset_address), get_asset_reserve(asset_address))\nEnd Function\n\n// Public price function for DERO to Asset trades with an exact output.\n// {assets_bought} Amount of Assets bought.\n// {asset_address} Address of the asset to trade.\n// @returns Amount of DERO needed to buy output Assets.\nFunction GetDeroToAssetOutputPrice(assets_bought Uint64, asset_address String) Uint64\n    10 IF assets_bought \u003e 0 THEN GOTO 30\n    20 RETURN 0\n    30 RETURN getOutputPrice(assets_bought, get_dero_reserve_per_asset(asset_address), get_asset_reserve(asset_address))\nEnd Function\n\n// Public price function for Asset to DERO trades with an exact input.\n// {assets_sold} Amount of Assets sold.\n// {asset_address} Address of the asset to trade.\n// @returns Amount of DERO that can be bought with input Assets.\nFunction GetAssetToDeroInputPrice(assets_sold Uint64, asset_address String) Uint64\n    10 IF assets_sold \u003e 0 THEN GOTO 30\n    20 RETURN 0\n    30 RETURN getInputPrice(assets_sold, get_asset_reserve(asset_address), get_dero_reserve_per_asset(asset_address))\nEnd Function\n\n// Public price function for Asset to DERO trades with an exact output.\n// {dero_bought} Amount of output DERO.\n// {asset_address} Address of the asset to trade.\n// @returns Amount of Assets needed to buy output DERO.\nFunction GetAssetToDeroOutputPrice(dero_bought Uint64, asset_address String) Uint64\n    10 IF dero_bought \u003e 0 THEN GOTO 30\n    20 RETURN 0\n    30 RETURN getOutputPrice(dero_bought, get_asset_reserve(asset_address), get_dero_reserve_per_asset(asset_address))\nEnd Function\n\nFunction mintFee(reserve0 Uint64, reserve1 Uint64, asset_address String) \n    10 DIM feeTo as String\n    11 DIM rootKLast as Uint64\n    20 LET feeTo = LOAD(\"feeTo\") \n    // Get the last root k for the asset\n    30 LET rootKLast = LOAD(asset_address+\":rootKLast\")\n    40 IF rootKLast != 0 THEN GOTO 50\n        41 RETURN \n    50 DIM rootK as Uint64\n    60 LET rootK = sqrt(reserve0) * sqrt(reserve1)\n    70 IF rootK \u003e rootKLast THEN GOTO 80\n        71 RETURN \n    80 DIM supply, liquidity_minted as Uint64\n    90 LET supply = get_supply_per_asset(asset_address)\n   100 LET liquidity_minted = mult_div(supply, rootK - rootKLast, rootK * 5 + rootKLast)\n   110 IF liquidity_minted \u003e 0 THEN GOTO 111 ELSE GOTO 120\n       111 increase_provider_liquidity_by(feeTo, liquidity_minted, asset_address)\n       112 set_supply_per_asset(supply + liquidity_minted, asset_address)\n   120 RETURN \nEnd Function\n\n// Helper functions \n// Encapsulated to better understand what's happening and absctract BOO storage schema\n// from main code.\n\nFunction set_supply_per_asset(amount Uint64, asset_address String) \n    10 STORE(asset_address+\":BOO\", amount)\n    20 RETURN\nEnd Function\n\nFunction get_supply_per_asset(asset_address String) Uint64\n    10 IF EXISTS(asset_address+\":BOO\") THEN GOTO 30\n    20 RETURN 0\n    30 RETURN LOAD(asset_address+\":BOO\")\nEnd Function\n\nFunction set_dero_reserve_per_asset(amount Uint64, asset_address String)\n    10 STORE(asset_address+\":DERO\", amount)\n    20 RETURN \nEnd Function\n\nFunction get_dero_reserve_per_asset(asset_address String) Uint64\n    10 RETURN LOAD(asset_address+\":DERO\")\nEnd Function\n\nFunction set_asset_reserve(amount Uint64, asset_address String) \n    10 STORE(asset_address, amount)\n    20 RETURN \nEnd Function\n\nFunction get_asset_reserve(asset_address String) Uint64\n    20 RETURN LOAD(asset_address)\nEnd Function\n\nFunction increase_provider_liquidity_by(provider_address String, amount Uint64, asset_address String)\n    10 IF EXISTS(ADDRESS_STRING(provider_address)+\":BOO:\"+asset_address) THEN GOTO 40\n    20 STORE(ADDRESS_STRING(provider_address)+\":BOO:\"+asset_address, amount)\n    30 RETURN\n    40 STORE(ADDRESS_STRING(provider_address)+\":BOO:\"+asset_address, get_provider_liquidity(provider_address, asset_address) + amount)\n    50 RETURN\nEnd Function\n\nFunction decrease_provider_liquidity_by(provider_address String, amount Uint64, asset_address String)\n    10 STORE(ADDRESS_STRING(provider_address)+\":BOO:\"+asset_address, get_provider_liquidity(provider_address, asset_address) - amount)\n    20 RETURN\nEnd Function\n\nFunction get_provider_liquidity(provider_address String, asset_address String) Uint64\n    10 RETURN LOAD(ADDRESS_STRING(provider_address)+\":BOO:\"+asset_address)\nEnd Function\n\nFunction will_addition_overflow(a Uint64, b Uint64) Uint64\n    10 IF (a \u003e 18446744073709551615 - b) THEN GOTO 100\n    20 RETURN 0 // No overflow\n    100 RETURN 1 // Overflow\nEnd Function\n\n// From Pieswap\n// lossless (a * b ) / c\nFunction mult_div(a Uint64, b Uint64, c Uint64) Uint64\n\t10 DIM base, maxdiv AS Uint64\n\t20 LET base = 4294967296\t// (1\u003c\u003c32)\n\t30 LET maxdiv = (base-1)*base + (base-1)\n\n\t50 DIM res AS Uint64\n\t60 LET res = (a/c) * b + (a%c) * (b/c)\n\t70 LET a = a % c\n\t80 LET b = b % c\n\t90 IF (a == 0 || b == 0) THEN GOTO 1000\n\n\t100 IF (c \u003e= base) THEN GOTO 200\n\t110 LET res = res + (a*b/c)\n\t120 GOTO 1000\n\n\t200 DIM norm AS Uint64\n\t210 LET norm = maxdiv/c\n\t220 LET c = c * norm\n\t230 LET a = a * norm\n\n\t300 DIM ah, al, bh, bl, ch, cl AS Uint64\n\t310 LET ah = a / base\n\t320 LET al = a % base\n\t330 LET bh = b / base\n\t340 LET bl = b % base\n\t350 LET ch = c / base\n\t360 LET cl = c % base\n\n\t400 DIM p0, p1, p2 AS Uint64\n\t410 LET p0 = al*bl\n\t420 LET p1 = p0 / base + al*bh\n\t430 LET p0 = p0 % base\n\t440 LET p2 = p1 / base + ah*bh\n\t450 LET p1 = (p1 % base) + ah*bl\n\t460 LET p2 = p2 + p1 / base\n\t470 LET p1 = p1 % base\n\n\t500 DIM q0, q1, rhat AS Uint64\n\t510 LET p2 = p2 % c\n\t520 LET q1 = p2 / ch\n\t530 LET rhat = p2 % ch\n\n\t600 IF (q1 \u003c base \u0026\u0026 (rhat \u003e= base || q1*cl \u003c= rhat*base+p1)) THEN GOTO 700\n\t610 LET q1 = q1 - 1\n\t620 LET rhat = rhat + ch\n\t630 GOTO 600\n\n\t700 LET p1 = ((p2 % base) * base + p1) - q1 * cl\n\t710 LET p2 = (p2 / base * base + p1 / base) - q1 * ch\n\t720 LET p1 = (p1 % base) + (p2 % base) * base\n\t730 LET q0 = p1 / ch\n\t740 LET rhat = p1 % ch\n\n\t800 IF (q0 \u003c base \u0026\u0026 (rhat \u003e= base || q0*cl \u003c= rhat*base+p0)) THEN GOTO 900\n\t810 LET q0 = q0 - 1\n\t820 LET rhat = rhat + ch\n\t830 GOTO 800\n\n\t900 LET res = res + q0 + q1 * base\n\n\t1000 RETURN res\nEnd Function\n    \n// babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)\nFunction sqrt(y Uint64) Uint64\n    10 IF y \u003e 3 THEN GOTO 20 ELSE GOTO 90\n    20 DIM x,z as Uint64\n    30 LET z = y \n    40 LET x = y / 2 + 1\n    50 IF x \u003c z THEN GOTO 60 ELSE GOTO 130\n    60 LET z = x\n    70 LET x = (y / x + x) / 2\n    80 GOTO 50\n    90 IF y != 0 THEN GOTO 110 ELSE GOTO 120\n   110 RETURN 1\n   120 RETURN 0\n   130 RETURN z\nEnd Function\n\nFunction UpdateCode(code String) Uint64 \n    10  IF LOAD(\"owner\") == SIGNER() THEN GOTO 30 \n    20  RETURN 1\n    30  UPDATE_SC_CODE(code)\n    40  RETURN 0\nEnd Function\n"}]