+++ /dev/null
-/*
-Package equity provides a compiler for Bytom's Equity contract language.
-
-A contract is a means to lock some payment in the output of a
-transaction. It contains a number of clauses, each describing a way to
-unlock, or redeem, the payment in a subsequent transaction. By
-executing the statements in a clause, using contract arguments
-supplied by the payer and clause arguments supplied by the redeemer,
-nodes in a Bytom network can determine whether a proposed spend is
-valid.
-
-The language definition is in flux, but here's what's implemented as
-of late Nov 2018.
-
- program = contract*
-
- contract = "contract" identifier "(" [params] ")" "locks" amount_identifier of asset_identifier "{" clause+ "}"
-
- The value(amount_identifier of asset_identifier) after "locks" is a name for
- the value locked by the contract. It must be unlocked or re-locked (with "unlock"
- or "lock") in every clause.
-
- clause = "clause" identifier "(" [params] ")" "{" statement+ "}"
-
- statement = verify | unlock | lock | define | assign | if/else
-
- verify = "verify" expr
-
- Verifies that boolean expression expr produces a true result.
-
- unlock = "unlock" expr "of" expr
-
- The first expr must be an amount, the second must be an asset.
- the value(expr "of" expr) must evaluate to the contract value.
- This unlocks that value for any use.
-
- lock = "lock" expr "of" expr "with" expr
-
- The first expr must be an amount, the second must be an asset.
- The later expr after "with" must be a program. This expression describe that
- the value(expr "of" expr) is unlocked and re-locks it with the new program immediately.
-
- define = "define" identifier : TypeName ["=" expr]
-
- Define a temporary variable "identifier" with type "TypeName". the identifier can be defined only
- or assigned with expr.
-
- assign = "assign" identifier "=" expr
-
- Assign a temporary variable "identifier" with expr. Please note that
- the "identifier" must be the defined variable with "define" expression.
-
- if = "if" expr "{" statement+ "}" [else "{" statement+ "}"]
-
- The check condition after "if" must be boolean expression. The if-else executes the statements
- inside the body of if-statement when condition expression is true, otherwise executes the statements
- inside the body of else-statement.
-
- params = param | params "," param
-
- param = identifier ":" type
-
- The identifier are individual parameter name. The identifier after the colon is their type.
- Available types are:
-
- Amount; Asset; Boolean; Hash; Integer; Program;
- PublicKey; Signature; String
-
- idlist = identifier | idlist "," identifier
-
- expr = unary_expr | binary_expr | call_expr | identifier | "(" expr ")" | literal
-
- unary_expr = unary_op expr
-
- binary_expr = expr binary_op expr
-
- call_expr = expr "(" [args] ")"
-
- If expr is the name of an Equity contract, then calling it (with
- the appropriate arguments) produces a program suitable for use
- in "lock" statements.
-
- Otherwise, expr should be one of these builtin functions:
-
- sha3(x)
- SHA3-256 hash of x.
- sha256(x)
- SHA-256 hash of x.
- size(x)
- Size in bytes of x.
- abs(x)
- Absolute value of x.
- min(x, y)
- The lesser of x and y.
- max(x, y)
- The greater of x and y.
- checkTxSig(pubkey, signature)
- Whether signature matches both the spending
- transaction and pubkey.
- concat(x, y)
- The concatenation of x and y.
- concatpush(x, y)
- The concatenation of x with the bytecode sequence
- needed to push y on the BVM stack.
- below(x)
- Whether the spending transaction is happening before
- blockHeight x.
- above(x)
- Whether the spending transaction is happening after
- blockHeight x.
- checkTxMultiSig([pubkey1, pubkey2, ...], [sig1, sig2, ...])
- Like checkTxSig, but for M-of-N signature checks.
- Every sig must match both the spending transaction and
- one of the pubkeys. There may be more pubkeys than
- sigs, but they are only checked left-to-right so must
- be supplied in the same order as the sigs. The square
- brackets here are literal and must appear as shown.
-
- unary_op = "-" | "~"
-
- binary_op = ">" | "<" | ">=" | "<=" | "==" | "!=" | "^" | "|" |
- "+" | "-" | "&" | "<<" | ">>" | "%" | "*" | "/"
-
- args = expr | args "," expr
-
- literal = int_literal | str_literal | hex_literal
-
-*/
-package compiler
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