ruby-on-rails - 解析红宝石代码

Question

我需要帮助解决一个问题。我有一个表，其中的列包含一些 ruby​​ 代码，如下所示：self.org_premium = self.volume / 12 * 0.1492 self.billing_premium = self.subscriber_premium + self.org_premiumoremployment_level == 'P'或vol_life.save. 现在我想在这些字符串中查找方法，但是某些 Rails 方法，比如saveornil?必须被忽略。我使用了 Ripper，但他的方法slice只返回 1 个参数。也许你对此有一些想法？

Answer 1

当您使用Ripper进行切片时，例如：

$ irb
2.0.0p247 :001 > p Ripper.slice('def m(a) nil end', 'ident')

要查看可用的事件，只需评估它在文档中引用的常量：EVENTS 进一步分解为 PARSER_EVENTS 和 SCANNER_EVENTS。

$ irb
2.0.0p247 :001 > require 'ripper'
2.0.0p247 :002 > Ripper::EVENTS
 => [:BEGIN, :END, :alias, :alias_error, :aref, :aref_field, :arg_ambiguous, :arg_paren, :args_add, :args_add_block, :args_add_star, :args_new, :array, :assign, :assign_error, :assoc_new, :assoc_splat, :assoclist_from_args, :bare_assoc_hash, :begin, :binary, :block_var, :block_var_add_block, :block_var_add_star, :blockarg, :bodystmt, :brace_block, :break, :call, :case, :class, :class_name_error, :command, :command_call, :const_path_field, :const_path_ref, :const_ref, :def, :defined, :defs, :do_block, :dot2, :dot3, :dyna_symbol, :else, :elsif, :ensure, :excessed_comma, :fcall, :field, :for, :hash, :if, :if_mod, :ifop, :lambda, :magic_comment, :massign, :method_add_arg, :method_add_block, :mlhs_add, :mlhs_add_star, :mlhs_new, :mlhs_paren, :module, :mrhs_add, :mrhs_add_star, :mrhs_new, :mrhs_new_from_args, :next, :opassign, :operator_ambiguous, :param_error, :params, :paren, :parse_error, :program, :qsymbols_add, :qsymbols_new, :qwords_add, :qwords_new, :redo, :regexp_add, :regexp_literal, :regexp_new, :rescue, :rescue_mod, :rest_param, :retry, :return, :return0, :sclass, :stmts_add, :stmts_new, :string_add, :string_concat, :string_content, :string_dvar, :string_embexpr, :string_literal, :super, :symbol, :symbol_literal, :symbols_add, :symbols_new, :top_const_field, :top_const_ref, :unary, :undef, :unless, :unless_mod, :until, :until_mod, :var_alias, :var_field, :var_ref, :vcall, :void_stmt, :when, :while, :while_mod, :word_add, :word_new, :words_add, :words_new, :xstring_add, :xstring_literal, :xstring_new, :yield, :yield0, :zsuper, :CHAR, :__end__, :backref, :backtick, :comma, :comment, :const, :cvar, :embdoc, :embdoc_beg, :embdoc_end, :embexpr_beg, :embexpr_end, :embvar, :float, :gvar, :heredoc_beg, :heredoc_end, :ident, :ignored_nl, :int, :ivar, :kw, :label, :lbrace, :lbracket, :lparen, :nl, :op, :period, :qsymbols_beg, :qwords_beg, :rbrace, :rbracket, :regexp_beg, :regexp_end, :rparen, :semicolon, :sp, :symbeg, :symbols_beg, :tlambda, :tlambeg, :tstring_beg, :tstring_content, :tstring_end, :words_beg, :words_sep]
2.0.0p247 :009 > Ripper::PARSER_EVENTS
 => [:BEGIN, :END, :alias, :alias_error, :aref, :aref_field, :arg_ambiguous, :arg_paren, :args_add, :args_add_block, :args_add_star, :args_new, :array, :assign, :assign_error, :assoc_new, :assoc_splat, :assoclist_from_args, :bare_assoc_hash, :begin, :binary, :block_var, :block_var_add_block, :block_var_add_star, :blockarg, :bodystmt, :brace_block, :break, :call, :case, :class, :class_name_error, :command, :command_call, :const_path_field, :const_path_ref, :const_ref, :def, :defined, :defs, :do_block, :dot2, :dot3, :dyna_symbol, :else, :elsif, :ensure, :excessed_comma, :fcall, :field, :for, :hash, :if, :if_mod, :ifop, :lambda, :magic_comment, :massign, :method_add_arg, :method_add_block, :mlhs_add, :mlhs_add_star, :mlhs_new, :mlhs_paren, :module, :mrhs_add, :mrhs_add_star, :mrhs_new, :mrhs_new_from_args, :next, :opassign, :operator_ambiguous, :param_error, :params, :paren, :parse_error, :program, :qsymbols_add, :qsymbols_new, :qwords_add, :qwords_new, :redo, :regexp_add, :regexp_literal, :regexp_new, :rescue, :rescue_mod, :rest_param, :retry, :return, :return0, :sclass, :stmts_add, :stmts_new, :string_add, :string_concat, :string_content, :string_dvar, :string_embexpr, :string_literal, :super, :symbol, :symbol_literal, :symbols_add, :symbols_new, :top_const_field, :top_const_ref, :unary, :undef, :unless, :unless_mod, :until, :until_mod, :var_alias, :var_field, :var_ref, :vcall, :void_stmt, :when, :while, :while_mod, :word_add, :word_new, :words_add, :words_new, :xstring_add, :xstring_literal, :xstring_new, :yield, :yield0, :zsuper] 
2.0.0p247 :010 > Ripper::SCANNER_EVENTS
 => [:CHAR, :__end__, :backref, :backtick, :comma, :comment, :const, :cvar, :embdoc, :embdoc_beg, :embdoc_end, :embexpr_beg, :embexpr_end, :embvar, :float, :gvar, :heredoc_beg, :heredoc_end, :ident, :ignored_nl, :int, :ivar, :kw, :label, :lbrace, :lbracket, :lparen, :nl, :op, :period, :qsymbols_beg, :qwords_beg, :rbrace, :rbracket, :regexp_beg, :regexp_end, :rparen, :semicolon, :sp, :symbeg, :symbols_beg, :tlambda, :tlambeg, :tstring_beg, :tstring_content, :tstring_end, :words_beg, :words_sep] 

在这种情况下，'ident' 是方法名称定义的事件，并且该事件实际上并不等同于代码中调用的方法。

我不确定 Ripper 是否是解析所使用的方法名称的最简单方法。此外，Ruby 处理由 处理的调用的能力method_missing确实使得很难看到可以解释的内容。

就像我在评论中所说的那样，还有其他几种方法可以解析您可能会研究的方法。

你甚至可以用字符串操作/检查可用方法来做类似的事情，例如

class A
  IGNORE = %w{save nil?}

  def find_possible_methods(s)
    s.split(/[\-\ ,\.\(\)\{\}\[\]]/).reject{|c| c =~ /[0-9\*\-\/\+\%\=\~].*/ || c.empty? || IGNORE.include?(c)}
  end

  def find_implemented_methods(s)
    (s.split(/[\-\ ,\.\(\)\{\}\[\]]/) & (methods + private_methods).collect(&:to_s)).reject{|c| IGNORE.include?(c)}
  end
end

用法：

a = A.new
 => #<A:0x007facb9a94be8> 
a.find_possible_methods 'self.org_premium = self.volume / 12 * 0.1492 self.billing_premium = self.subscriber_premium + self.org_premium'
 => ["self", "org_premium", "self", "volume", "self", "billing_premium", "self", "subscriber_premium", "self", "org_premium"]