{"rsdb":{"rid":"377756","subhead":"","postdate":"0","aid":"264298","fid":"87","uid":"1","topic":"1","content":"
\n

\u5728\u5982 rails \u8fd9\u6837\u7684\u5f00\u6e90\u5e93\u4e2d\uff0c\u6211\u4eec\u5e38\u5e38\u89c1\u5230\u8fd9\u6837\u7684\u4e00\u7c7b\u5199\u6cd5\uff1a<\/p> \n 

class_eva l <<-RUBY, __FILE__, __LINE__ + 1\n  def xxx\n    # do something here\n  end\nRUBY\n<\/code><\/pre> \n 
\u4ee4\u4eba\u56f0\u60d1\u4e0d\u5df2\u3002<\/p> \n 
\u4e0d\u8fc7\u8fd9\u91cc\u7684\u77e5\u8bc6\u70b9\u975e\u5e38\u7b80\u5355\uff0c\u53ea\u8981\u638c\u63e1\u4e86 heredoc \u4e0e eva l \u7684\u7528\u6cd5\uff0c\u5c31\u5f88\u597d\u7406\u89e3\u8fd9\u91cc\u7684\u4ee3\u7801\u4e86\u3002<\/p> \n 
heredoc<\/h2> \n 
heredoc \u662f\u4e00\u79cd\u5b9a\u4e49\u591a\u884c\u5b57\u7b26\u4e32\u7684\u65b9\u6cd5\uff0c\u540c\u65f6\u4fdd\u6301\u539f\u59cb\u7f29\u8fdb\u548c\u683c\u5f0f\u3002\u76f8\u5f53\u4e8e java<\/a> script \u4e2d\u7684 ``\u3002<\/p> \n 
heredoc \u4ee5 <<-<\/code> \u5f00\u5934\uff0c\u8ddf\u4e0a\u4e00\u4e2a\u968f\u610f\u7684\u5355\u8bcd\uff0c\u6700\u540e\u518d\u4ee5\u8fd9\u4e2a\u5b57\u7b26\u4e32\u7ed3\u675f\uff1a<\/p> \n 
multi_str = <<-FOO\n1\n  2\n    3\nFOO\n\nputs multi_str\n<\/code><\/pre> \n 
\u591a\u884c\u5b57\u7b26\u4e32\u4f1a\u4fdd\u7559\u6240\u6709\u7684\u7f29\u8fdb\uff0c\u5e76\u4e14\u5728\u5c3e\u90e8\u4f1a\u5e26\u4e0a \\n<\/code> \u6362\u884c\u7b26\u3002<\/p> \n 
\u5bf9\u4e8e\u6362\u884c\u7b26\uff0c\u53ef\u4ee5\u4f7f\u7528 chomp<\/code> \u6765\u53bb\u9664\uff1a<<-FOO.chomp<\/code>\u3002<\/p> \n 
\u5982\u679c\u4f60\u5728\u7f29\u8fdb\u7684\u60c5\u51b5\u4e0b\u58f0\u660e heredoc\uff0c\u53ef\u80fd\u4f1a\u53d8\u6210\u8fd9\u6837\uff0c\u5341\u5206\u4e11\u964b\uff1a<\/p> \n 
    multi_str = <<-FOO\n1\n  2\n    3\n    FOO\n<\/code><\/pre> \n 
\u5982\u679c\u4fdd\u6301\u7f29\u8fdb\uff1a<\/p> \n 
    multi_str = <<-FOO\n    1\n      2\n        3\n    FOO\n<\/code><\/pre> \n 
\u6700\u540e\u7684\u8f93\u51fa\u7ed3\u679c\u4e5f\u4f1a\u5e26\u4e0a 1 \u6240\u6709\u7f29\u8fdb\uff0c\u8fd9\u91cc\u53ef\u4ee5\u4f7f\u7528 ~<\/code> \u4ee3\u66ff -<\/code>\uff0c\u6216\u662f\u4f7f\u7528 strip<\/code>\u3002<\/p> \n 
    multi_str = <<~FOO\n    1\n      2\n        3\n    FOO\n    multi_str = <<-FOO.strip\n    1\n      2\n        3\n    FOO\n<\/code><\/pre> \n 
\u8fd9\u4e24\u79cd\u65b9\u5f0f\u90fd\u4f1a\u4ee5\u7b2c\u4e00\u884c\u4e3a\u6807\u51c6\uff0c\u5728\u6240\u6709\u884c\u7684\u5f00\u5934\uff0c\u5220\u9664\u7a7a\u683c\u3002<\/p> \n 
eva l<\/h2> \n 
eva l \u5728\u5f88\u591a\u811a\u672c\u8bed\u8a00\u4e2d\u90fd\u5b58\u5728\uff0c\u5b83\u53ef\u4ee5\u8ba9\u6211\u4eec\u5c06\u5b57\u7b26\u4e32\u4f5c\u4e3a\u4ee3\u7801\u6267\u884c\u3002<\/p> \n 
ruby \u4e2d\u5b58\u5728\u591a\u4e2a eva l \u65b9\u6cd5\uff0c\u6bd4\u5982 eva l<\/code> class_eva l<\/code> module_eva l<\/code> instance_eva l<\/code> \u7b49\u3002<\/p> \n 
\u4ed6\u4eec\u5206\u522b\u53ef\u4ee5\u5b9e\u73b0\u4e0d\u540c\u7684 eva l \u529f\u80fd\u3002<\/p> \n 
\u4ee5 class_eva l<\/code> \u4e3a\u4f8b\uff1a<\/p> \n 
class Foo\n  STR = <<-RUBY\n    def say\n      p 'I am Foo'\n    end\n  RUBY\n\n  Module.class_eva l STR\nend\n\nFoo.say\n<\/code><\/pre> \n 
\u6211\u4eec\u53ef\u4ee5\u8f7b\u677e\u5c06\u5b57\u7b26\u4e32\u53d8\u6210\u65b9\u6cd5\u3002<\/p> \n 
\u4ee3\u7801\u5206\u6790<\/h2> \n 
\u73b0\u5728\u6211\u4eec\u7ec8\u4e8e\u53ef\u4ee5\u770b\u61c2\u8fd9\u6bb5\u4ee3\u7801\u4e86\uff0c\u5b83\u5176\u5b9e\u5c31\u662f\u4f7f\u7528\u4e86 heredoc \u591a\u884c\u5b57\u7b26\u4e32\uff0c\u5c06\u5b57\u7b26\u4e32\u91cc\u53d8\u6210\u4e86\u4e00\u4e2a\u771f\u6b63\u7684 ruby \u65b9\u6cd5\u3002<\/p> \n 
class_eva l <<-RUBY, __FILE__, __LINE__ + 1\n  def xxx\n    # do something here\n  end\nRUBY\n<\/code><\/pre> \n 
\u90a3\u4e48\u540e\u9762\u7684 __FILE__, __LINE__ + 1<\/code> \u6709\u4ec0\u4e48\u7528\u5462\uff1f<\/p> \n 
\u5176\u5b9e\u6211\u4eec\u5b8c\u5168\u53ef\u4ee5\u4e0d\u4f20\u8fd9\u4e24\u4e2a\u53c2\u6570\u3002<\/p> \n 
\u4f46\u662f\u52a0\u5165\u6211\u4eec\u5b57\u7b26\u4e32\u751f\u6210\u7684\u65b9\u6cd5\u62a5\u4e86\u9519\u8be5\u600e\u4e48\u529e\u5462\uff1f\u4e00\u822c\u6211\u4eec\u7684\u65b9\u6cd5\u62a5\u9519\u90fd\u4f1a\u6709\u6587\u4ef6\u540d\u3001\u884c\u53f7\u3002<\/p> \n 
eva l \u4f7f\u7528\u5b57\u7b26\u4e32\u751f\u6210\u65b9\u6cd5\uff0c\u81ea\u7136\u6ca1\u6709\u8fd9\u4e9b\u4e1c\u897f\uff0c\u6240\u4ee5\u6211\u4eec\u4f20\u5165\u5f53\u524d\u6587\u4ef6\u7684\u6587\u4ef6\u540d\uff0c\u548c\u5f53\u524d\u884c\u7684\u884c\u53f7+1\uff0c\u6765\u5e2e\u52a9 Ruby \u751f\u6210\u66f4\u597d\u7684\u62a5\u9519\u4fe1\u606f\u3002<\/p> \n 
\uff08\u5b8c\uff09<\/p> \n<\/div>","orderid":"0","title":"Ruby \u7684 heredoc \u4e0e eva l","smalltitle":"","mid":"0","fname":"Ruby","special_id":"0","bak_id":"0","info":"0","hits":"292","pages":"1","comments":"0","posttime":"2023-07-23 13:24:51","list":"1690089891","username":"admin","author":"","copyfrom":"","copyfromurl":"","titlecolor":"","fonttype":"0","titleicon":"0","picurl":"https:\/\/www.cppentry.com\/upload_files\/","ispic":"0","yz":"1","yzer":"","yztime":"0","levels":"0","levelstime":"0","keywords":"Ruby<\/A> heredoc<\/A> eva<\/A>","jumpurl":"","iframeurl":"","style":"","template":"a:3:{s:4:\"head\";s:0:\"\";s:4:\"foot\";s:0:\"\";s:8:\"bencandy\";s:0:\"\";}","target":"0","ip":"119.59.235.169","lastfid":"0","money":"0","buyuser":"","passwd":"","allowdown":"","allowview":"","editer":"","edittime":"0","begintime":"0","endtime":"0","description":"Ruby \u7684 heredoc \u4e0e eva l","lastview":"1716082044","digg_num":"0","digg_time":"0","forbidcomment":"0","ifvote":"0","heart":"","htmlname":"","city_id":"0"},"page":"1"}