{"id":365,"date":"2012-04-14T22:03:05","date_gmt":"2012-04-14T20:03:05","guid":{"rendered":"http:\/\/misto.ch\/?p=365"},"modified":"2012-04-14T22:03:05","modified_gmt":"2012-04-14T20:03:05","slug":"expand-case-class-bindings-in-pattern-matching","status":"publish","type":"post","link":"https:\/\/misto.ch\/de\/2012\/04\/14\/expand-case-class-bindings-in-pattern-matching\/","title":{"rendered":"Quickfix to Expand Case-Class Bindings in Pattern Matching"},"content":{"rendered":"

When writing Scala code that involves pattern matching I often work with (nested) case classes and sequences of case classes. I usually start with a simple binding like this<\/p>\n

\ncase class Person(firstName: String, lastName: String)\n\nList(Person("Mirko", "Stocker")) match {\n  case person :: Nil =>; ...\n}\n<\/pre>\n
and then when I need to access members of the matched class convert it to use the extractor:<\/p>\n
\nList(Person("Mirko", "Stocker")) match {\n  case Person(firstName, lastName) :: Nil => ...\n}\n<\/pre>\n
What’s tedious about that step is that one needs to know how many arguments there are and name all the bindings. But not for much longer! I wrote a quick-fix for the Scala IDE that does this for you:<\/p>\n
\"\"<\/a><\/p>\n
Ctrl+1 brings up the available quick fixes:<\/p>\n
\"\"<\/a><\/p>\n
\"\"<\/a><\/p>\n
And this is what happens when the binding you’re expanding is used in the pattern’s body:<\/p>\n
\"\"<\/a><\/p>\n
It also works if you use a typed pattern where the type is a case class:<\/p>\n
\"\"<\/a><\/p>\n
\"\"<\/a><\/p>\n
This feature isn’t in the recently released Milestone 1<\/a>, but it should be part of the next one (or one of the upcoming nightly builds<\/a>). Suggestions for a better wording – expand case class binding – are welcome \ud83d\ude42<\/p>\n","protected":false},"excerpt":{"rendered":"
When writing Scala code that involves pattern matching I often work with (nested) case classes and sequences of case classes. I usually start with a simple binding like this case class Person(firstName: String, lastName: String) List(Person("Mirko", "Stocker")) match { case person :: Nil =>; … } and then when I need to access members of […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[27],"tags":[37,38],"class_list":["post-365","post","type-post","status-publish","format-standard","hentry","category-scala","tag-refactoring","tag-scala"],"_links":{"self":[{"href":"https:\/\/misto.ch\/de\/wp-json\/wp\/v2\/posts\/365","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/misto.ch\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/misto.ch\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/misto.ch\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/misto.ch\/de\/wp-json\/wp\/v2\/comments?post=365"}],"version-history":[{"count":0,"href":"https:\/\/misto.ch\/de\/wp-json\/wp\/v2\/posts\/365\/revisions"}],"wp:attachment":[{"href":"https:\/\/misto.ch\/de\/wp-json\/wp\/v2\/media?parent=365"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/misto.ch\/de\/wp-json\/wp\/v2\/categories?post=365"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/misto.ch\/de\/wp-json\/wp\/v2\/tags?post=365"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}