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

Gerald Bauer wrote:
> Challenge #11 - Blockchain Contracts - Disassemble & Assemble Ethereum
Virtual Machine (EVM) Opcodes / Bytecodes

$ ruby -v lib/011.rb
ruby 2.6.0p0 (2018-12-25 revision 66547) [x86_64-linux]
Run options: --seed 51739
# Running:
...
Finished in 0.009713s, 308.8672 runs/s, 308.8672 assertions/s.
3 runs, 3 assertions, 0 failures, 0 errors, 0 skips

$ cat lib/011.rb
# frozen_string_literal: true
require_relative '../011/test.rb'

class RubyQuizTest
  @@op2hex = Ethereum::Opcodes::TABLE
             .transform_values{|v| v.to_s.freeze}

  @@hex2op = Ethereum::Opcodes::TABLE.invert
             .transform_values{|v| v.to_s(16).rjust(2, '0').freeze}

  def disassemble(hex)
    n = 0
    hex.chars.each_slice(2).map{|a,b|
      if n == 0
        c = "#{a}#{b}".to_i(16)
        t = (0x60..0x7f).include?(c) ? "#{n = c - 0x5f; ' 0x'}" : ''
        "\r\n#{@@op2hex[c]}#{t}"
      else
        n -= 1
        "#{a}#{b}"
      end
    }.join[8..]
  end

  def assemble(code)
    code.scan(/^(\w+)(?: 0x(\w+))?\r?$/).map{|a,b|
      "#{@@hex2op[a.intern]}#{b}"
    }.join.prepend('0x')
  end
end

Dir.chdir("#{__dir__}/../011")
RubyQuizTest.new('fjc')



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