Re: Ruby Quiz - Challenge #11 - Blockchain Contracts - Disassemble & Assemble Ethereum Virtual Machine (EVM) Opcodes / Bytecodes

Hello,

    Wow. Great to see high-speed Ethereum opscode / bytecode assemble
and disassemble versions in ruby.
Thanks again for keeping the ruby quiz going.

   For reference here's the test answer from my humble self:

def disassemble( hex )  # returns (code) text with opcodes
  hex = hex[2..-1]  if hex.start_with?( '0x' )    # cut off leading 0x

  bytes = [hex].pack('H*').bytes   # convert (hex) string to bytearray

  lines = []
  while bytes.size > 0
    opcode = bytes.shift

    ins = Ethereum::Opcodes::TABLE[opcode]
    if ins =~ /^PUSH([0-9]+)$/
      num  = $1.to_i
      args_hex = num.times.map { '%02x' % bytes.shift }.join
      lines << "#{ins} 0x#{args_hex}"
    else
      lines << "#{ins}"
    end
  end
  lines.join( "\n" )
end


def assemble( code )  # returns (hex) string
  hex = '0x'

  words = code.split
  words.each do |word|
    if word =~ /^0x/
      hex << word[2..-1]
    else  # assume instruction / opcode mnemonic
      opcode = Ethereum::Opcodes::REVERSE_TABLE[word.to_sym]
      hex << ('%02x' % opcode)
    end
  end
  hex

end


  Anyone else? You're (more than) welcome to post your code snippets /
version :-).

  Cheers. Prost.

PS: Find the collected code snippets / solutions [1] at the ruby quiz repo.

[1] https://github.com/planetruby/quiz/blob/master/011/solution.rb

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