{"id":208147,"date":"2025-07-08T15:59:04","date_gmt":"2025-07-08T07:59:04","guid":{"rendered":"https:\/\/server.hk\/cnblog\/208147\/"},"modified":"2025-07-08T15:59:04","modified_gmt":"2025-07-08T07:59:04","slug":"%e5%a0%86%e6%a0%88%e8%b7%9f%e8%b8%aa%e5%92%8c-golang-%e9%94%99%e8%af%af%e3%80%82unwrap","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/208147\/","title":{"rendered":"\u5806\u6808\u8ddf\u8e2a\u548c golang \u9519\u8bef\u3002Unwrap()"},"content":{"rendered":"

<\/b> <\/p>\n

\u5f53\u524d\u4f4d\u7f6e\uff1a ><\/span> ><\/span> ><\/span> ><\/span> \u5806\u6808\u8ddf\u8e2a\u548c golang \u9519\u8bef\u3002Unwrap()<\/span><\/p>\n

\u6765\u6e90\uff1astackoverflow<\/span>
\n2024-04-29 15:54:37<\/span>
\n<\/i>0\u6d4f\u89c8<\/span>
\n<\/i>\u6536\u85cf<\/span> <\/p>\n

\u5077\u5077\u52aa\u529b\uff0c\u6084\u65e0\u58f0\u606f\u5730\u53d8\u5f3a\uff0c\u7136\u540e\u60ca\u8273\u6240\u6709\u4eba\uff01\u54c8\u54c8\uff0c\u5c0f\u4f19\u4f34\u4eec\u53c8\u6765\u5b66\u4e60\u5566~\u4eca\u5929\u6211\u5c06\u7ed9\u5927\u5bb6\u4ecb\u7ecd\u300a\u5806\u6808\u8ddf\u8e2a\u548c golang \u9519\u8bef\u3002Unwrap()\u300b<\/span>\uff0c\u8fd9\u7bc7\u6587\u7ae0\u4e3b\u8981\u4f1a\u8bb2\u5230<\/span>\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u4e0d\u77e5\u9053\u5927\u5bb6\u5bf9\u5176\u90fd\u6709\u591a\u5c11\u4e86\u89e3\uff0c\u4e0b\u9762\u6211\u4eec\u5c31\u4e00\u8d77\u6765\u770b\u4e00\u5427\uff01\u5f53\u7136\uff0c\u975e\u5e38\u5e0c\u671b\u5927\u5bb6\u80fd\u591a\u591a\u8bc4\u8bba\uff0c\u7ed9\u51fa\u5408\u7406\u7684\u5efa\u8bae\uff0c\u6211\u4eec\u4e00\u8d77\u5b66\u4e60\uff0c\u4e00\u8d77\u8fdb\u6b65\uff01<\/p>\n

\u95ee\u9898\u5185\u5bb9
\n <\/p>\n

\u6211\u60f3\u6784\u5efa\u4e00\u4e2a\u5806\u6808\u8ddf\u8e2a\uff0c\u5176\u4e2d\u5305\u62ec\u4e00\u4e2a\u4f4e\u7ea7\u6570\u636e\u5e93\u9519\u8bef\u548c\u7b2c\u4e8c\u4e2a\u4eba\u7c7b\u53ef\u8bfb\u7684\u9519\u8bef\u3002<\/p>\n

golang 1.13 \u4e2d\u65b0\u7684 errors.unwrap()<\/code> \u51fd\u6570\u662f\u4e3a\u6b64\u76ee\u7684\u800c\u6784\u5efa\u7684\u5417\uff1f\u4e0d\u786e\u5b9a\u6211\u660e\u767d\u5982\u4f55\u4f7f\u7528\u5b83\u3002\u5bfb\u627e\u6709\u5173\u5982\u4f55\u6267\u884c\u6b64\u64cd\u4f5c\u7684\u793a\u4f8b\u3002<\/p>\n

\/\/ model\/book.go\npackage model\n\ntype Book struct {\n    Id     uint32  `json:\"id\"     db:\"id\"`\n    Title  string  `json:\"title\"  db:\"title\"`\n    Author string  `json:\"author\" db:\"author\"`\n    Price  float32 `json:\"price\"  db:\"price\"`\n}\n\nfunc (b *Book) Tablename() string {\n    return \"books\"\n}\n\n\n\/\/ main.go\npackage main\n\nfunc main() {\n    bk := model.Book{\n        Title:  \"oliver twist\",\n        Author: \"charles dickens\",\n        Price:  10.99,\n    }\n\n    err:= Create(&bk)\n    if err !=nil {\n        \/\/ how to use Unwrap?\n    }\n\n}\nfunc Create(book *model.Book) error {\n    insertSQL := \"INSERT INTO ....\"\n    \/\/ code to insert\n    if err != nil {\n        return err\n    }\n    book.Id = uint32(lastID)\n    return nil\n}<\/pre>\n
 <\/p>\n
\u89e3\u51b3\u65b9\u6848<\/h2>\n
 <\/p>\n
errors.unwrap<\/code> \u7528\u4e8e\u5265\u79bb\u5df2\u5305\u88c5\u7684\u9519\u8bef\u5c42\u3002<\/p>\n
\/\/ error 1 wrapped by 2 wrapped by 3\nerr1 := errors.new(\"error 1\")\nerr2 := fmt.errorf(\"error 2: %w\", err1)\nerr3 := fmt.errorf(\"error 3: %w\", err2)\n\nfmt.println(err1) \/\/ \"error 1\"\nfmt.println(err2) \/\/ \"error 2: error 1\"\nfmt.println(err3) \/\/ \"error 3: error 2: error 1\"\n\n\/\/ unwrap peels a layer off\nfmt.println(errors.unwrap(err3)) \/\/ \"error 2: error 1\"\nfmt.println(errors.unwrap(errors.unwrap(err3))) \/\/ \"error 1\"\n<\/pre>\n
\u60a8\u53ef\u4ee5\u9012\u5f52\u5730\u5c55\u5f00\u4ee5\u627e\u5230\u6700\u5185\u90e8\u7684\u9519\u8bef\uff1a<\/p>\n
currenterr := err3\nfor errors.unwrap(currenterr) != nil {\n  currenterr = errors.unwrap(currenterr)\n}\n\nfmt.println(currenterr) \/\/ \"error 1\"\n<\/pre>\n
\u5bf9\u4e8e\u540c\u65f6\u5305\u542b\u4f4e\u7ea7\u9519\u8bef\u548c\u4eba\u7c7b\u53ef\u8bfb\u9519\u8bef\u7684\u9519\u8bef\uff0c\u60a8\u53ef\u4ee5\u5b9e\u73b0\u81ea\u5b9a\u4e49\u9519\u8bef\u3002<\/p>\n
type error struct {\n  lowlevel error\n  humanreadable string\n}\n\nfunc (e error) error() string {\n  return e.humanreadable\n}\n\nfunc (e error) unwrap() error {\n  return e.lowlevel\n}\n\n\/\/ helper\nfunc newerror(inner error, outer string) *error {\n  return &error{\n    lowlevel: inner, \n    humanreadable: outer,\n  }\n}\n<\/pre>\n
\u5728\u60a8\u8c03\u7528\u7684\u51fd\u6570\u4e2d\uff1a<\/p>\n
func create(book *model.book) error {\n  ...\n\n  if err != nil {\n     return newerror(err, \"failed to create book\")\n  }\n\n  ...\n}\n<\/pre>\n
\u5728\u4f60\u7684\u6765\u7535\u8005\u4e2d\uff1a<\/p>\n
func main() {\n  ...\n  err := Create(&bk)\n  if err != nil {\n    log.Print(errors.Unwrap(err)) \/\/ internally log low-level error\n    fmt.Print(err) \/\/ present human-readable error to user\n  }\n  ...\n}\n<\/pre>\n
\u597d\u4e86\uff0c\u672c\u6587\u5230\u6b64\u7ed3\u675f\uff0c\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u300a\u5806\u6808\u8ddf\u8e2a\u548c golang \u9519\u8bef\u3002Unwrap()\u300b\uff0c\u5e0c\u671b\u672c\u6587\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff01\u5173\u6ce8\u516c\u4f17\u53f7\uff0c\u7ed9\u5927\u5bb6\u5206\u4eab\u66f4\u591aGolang\u77e5\u8bc6\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5f53\u524d\u4f4d\u7f6e\uff1a > > ...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4925],"tags":[],"class_list":["post-208147","post","type-post","status-publish","format-standard","hentry","category-4925"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/208147","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=208147"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/208147\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=208147"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=208147"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=208147"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}