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Locus Core Script

Fundamental scripts, such as Atomic Swap, can be executed directly on the Locus Chain core layer.
Execution on the core layer indicates that the process is lightweight enough for all regular nodes to handle, comparable to or only slightly more demanding than processing standard transactions.

Data Types​

TypeDescription
uint8uint8
uint16uint16
uint32uint32
uint64uint64
int8int8
int16int16
int32int32
int64int64
npknormal public key
nsignnormal signature
roundround
heightheight of account chain
digest32 bytes hash (blake2b256)
addressaddress of account
currencyamount of coin or token
summaryexample data type for data trading

OP Codes​

op codeoperand 1operand 2description
#verconst uint16-Take operand1 and check the VM version.
#txa1data type-Specify the data type of Args[0] for TxProvideScript and TxAcceptScript.
#txa2data type-Specify the data type of Args[1] for TxProvideScript and TxAcceptScript.
#txa3data type-Specify the data type of Args[2] for TxProvideScript and TxAcceptScript.
#txa4data type-Specify the data type of Args[3] for TxProvideScript and TxAcceptScript.
op0, push_false--Push 0 on stack. (1 byte)
op1, push_true--Push 1 on stack (1 byte). 1 is the only TRUE value.
op2 ~ op16--Push 2 ~ 16 on stack (1 byte)
ver--Pop 1 byte from stack and verify. If the value is 1, set mark to true and terminate the script. If the value is anything else, mark is set to false.
ret--Set mark to false and terminate the script.
if--Pop 1 byte from stack. If the value is 1, execute the IF clause. If the value is not 1 and an ELSE clause is present, execute the ELSE clause. Nested IF statements are supported.
ifn--Pop 1 byte from stack. If the value is not 1, execute the IF clause. If the value is 1 and an ELSE clause exists, execute the ELSE clause.
else--End of IF clause, beginning of ELSE clause.
eif--End of IF clause or ELSE clause.
push_txr1--Push Round value of TxProvideScript on stack.
push_txr2--Push Round value of TxAcceptScript on stack.
push_txh1--Push Height value of TxProvideScript on stack.
push_txh2--Push Height value of TxAcceptScript on stack.
push_txa1--Push value of Arg[0] from the transaction (Tx) on stack. Before executing this opcode, the data type must be specified as #txa1.
push_txa2--Push value of Arg[1] from the transaction (Tx) on stack. Before executing this opcode, the data type must be specified as #txa2.
push_txa3--Push value of Arg[2] from the transaction (Tx) on stack. Before executing this opcode, the data type must be specified as #txa3.
push_txa4--Push value of Arg[3] from the transaction (Tx) on stack. Before executing this opcode, the data type must be specified as #txa4.
hash_sha--Pop data from stack, calculate its hash value using SHA256, and push the resulting hash back on stack.
hash_blake--Pop data from stack, calculate its hash value using Blake2b256, and push the resulting hash back on stack.
root_summary--Pop summary from stack, compute the root of summary, and push the result back on stack.
equ--Pop data twice from stack, compare the two values, and push true if they are equal or false if they are not.
neq--Pop data twice from stack, compare the two values, and push true if they are not equal or false if they are equal.
lt--Pop data twice from stack. If the 1st pop < 2nd pop, push true; otherwise, push false.
lte--Pop data twice from stack. If the 1st pop <= 2nd pop, push true; otherwise, push false.
gt--Pop data twice from stack. If the 1st pop > 2nd pop, push true; otherwise, push false.
gte--Pop data twice from stack. If the 1st pop >= 2nd pop, push true; otherwise, push false.
dup--Push a copy of the topmost data on the stack. (Duplicate it) (stack: x, ... → x, x, ...)
drop--Pop data from stack and discard it. (stack: x, y, ... → y, ...)
swap--Pop data twice from the stack and push them back in reverse order. (stack: x, y, ... → y, x, ...)
rot--Rotate the top three pieces of data on the stack. (stack: x, y, z, ... → z, x, y, ...)
over--Copy the second data from the top of stack to the top. (stack: x, y, ... → y, x, y, ...)
add--Pop data twice from stack, add the two values, and push the result back on stack. (If the types differ, an error is returned.)

Samples​

Hashed Time Lock​

TxProvideScript :
    Target :              // The account to receive coin.
    TargetAfterTimeLock : // provider
    Args[0] :             // hash of seed
    ScriptProvide :
        #ver 1
        #txa1 digest
        push_txa1         // hash of seed
        ret
    ScriptAccept :
        #ver 1
        #txa1 digest
        push_txa1         // seed
        hash_blake        // make hash of seed
        equ               // compare provider's hash & acceptor's hash
        ver
 
TxAcceptScript :
    Args[0] :             // seed