github.com/decred/dcrd/txscript (go): Package txscript implements the Decred transaction script language.  This package provides data structures and functions to parse and execute decred transaction scripts.  Decred transaction scripts are written in a stack-base, FORTH-like language.  The Decred script language consists of a number of opcodes which fall into several categories such pushing and popping data to and from the stack, performing basic and bitwise arithmetic, conditional branching, comparing hashes, and checking cryptographic signatures.  Scripts are processed from left to right and intentionally do not provide loops.  The vast majority of Decred scripts at the time of this writing are of several standard forms which consist of a spender providing a public key and a signature which proves the spender owns the associated private key.  This information is used to prove the the spender is authorized to perform the transaction.  One benefit of using a scripting language is added flexibility in specifying what conditions must be met in order to spend decreds.  Errors returned by this package are of type txscript.Error.  This allows the caller to programmatically determine the specific error by examining the ErrorCode field of the type asserted txscript.Error while still providing rich error messages with contextual information.  A convenience function named IsErrorCode is also provided to allow callers to easily check for a specific error code.  See ErrorCode in the package documentation for a full list.
Keywords: blockchain|cryptocurrency|dcrd|decred|decred-daemon|decred-nodes|go|golang|p2p|peer-to-peer