ios - Swift: calling failable initializer from throwing initializer? -


i have need extend struct having failable initializer throwing initializer calling failable initializer. , see no elegant or clear way in swift 3.1.

something this:

extension product: jsondecodable {      public enum error: swift.error {         case unabletoparsejson     }      init(decodefromjson json: json) throws {         guard let jsonobject = json as? jsonobject else {             throw error.unabletoparsejson         }          // meta-code         self.init(dictionary: jsonobject) ?? throw error.unabletoparsejson     } }

is there elegant , clean way that?

found semi-clean way while writing question:

extension product: jsondecodable {      public enum error: swift.error {         case unabletoparsejson     }      init(decodefromjson json: json) throws {         guard let jsonobject = json as? jsonobject,             let initialized = type(of: self).init(dictionary: jsonobject)         else {             throw error.unabletoparsejson         }          self = initialized     } }

Comments

Post a Comment

Popular posts from this blog

'hasOwnProperty' in javascript -

i use obj.hasownproperty judge whether object has property, when replaced obj[prop] !== undefined , not normal implementation, ask, why behind method can not use it? object.hasownproperty(prop); object[prop] !== undefined; obj[prop] !== undefined wrong 2 reasons: you can explicitly set property undefined , obj[prop] = undefined; . obj.hasownproperty(prop) return true in case. obj[prop] follow prototype chain, return property that's inherited. obj.hasownproperty(prop) returns true if property exists directly in object, returns false inherited properties.
Read more

python - ValueError: No axis named 1 for object type <class 'pandas.core.series.Series'> -

i´m new programming. i´m trying use scipy minimize, had several issues , gotten through of them. right code, i'm not understanding why i´m getting error. par_opt = so.minimize(fun=fun_obj, x0=par_ini, method='nelder-mead', args=[series_pt_cal, dt, series_caudal_cal]) not enough info given op, somewhere in code it's specified operate data frame column (axis=1) on object pandas series. if code typically works occasional gives errors, check degenerative cases data frame may have 1 row. pandas has nasty habit of guessing want -- may decide reduce 1-row data frame series (e.g., apply() function; can disable using reduce=false in there). add line of code check object isinstance(df, pd.dataframe) or else convert offending pandas series data frame, s.to_frame().t problems had deal with.
Read more

java - How to implement an entity bound odata action in olingo v4.3 -

similar post, i'm trying implement action bound entity how create bounded action in olingo v4 (java) but 500 no error logged when metadata document. in answer above linked question, there no mention of getactionimport() implementation described in olingo tutorial, , wonder if needs modified entity-bound action? how can olingo log error causing 500? getting debug output quite easy: handler.register(new defaultdebugsupport()); where handler odatahttphandler armed this, , after examination of olingo-server-core code, discovered: you don't need actionimport @ bound actions. the action name in url needs qualified namespace, https://issues.oasis-open.org/browse/odata-812 has not been implemented. when built client url using org.apache.olingo.client.api.uri.uribuilder , wrapped entity id in single quotes, , olingo server threw exception, reverted using stringbuilder
Read more