heyo I pushed it a bit further last two evenings and got bas

Question

heyo I pushed it a bit further last two evenings and got basic support for sealed classes working in <https github com arrow kt arrow meta pull 707|this PR> for now only it supports data class with one parameter because I need to pass the info about index of parameter to IR level somehow Problem for tomorrow I also had to rewrite some parts of analysis Now we go through contents of all files and check when expressions directly instead of relying on diagnostics to detect them And the last change we also have a `todo` property in the prelude which serves as a placeholder to complete calls in PSI also merged master so sorry for a bit messy changeset

shikasd · Answer

< mattmoore> pinging you as usual slightly smiling face

mattmoore · Answer

Nice I ll take a look soon slightly smiling face

mattmoore · Answer

< shikasd> Just updated upstream pattern matching branch with master Can you try rebasing on upstream pattern matching branch

shikasd · Answer

thanks just did this seems like tests got merged a bit weirdly will fix this now

shikasd · Answer

seems alright now

mattmoore · Answer

thumbsup

mattmoore · Answer

< shikasd> This is really neat I didn t know you could create your own slice with custom types ```val PATTERN EXPRESSION = Slices createSimpleSlice lt KtWhenEntry PatternExpression gt val PATTERN EXPRESSION CAPTURED PARAMS = Slices createCollectiveSetSlice lt KtNameReferenceExpression gt val PATTERN EXPRESSION BODY PARAMS = Slices createCollectiveSetSlice lt KtSimpleNameExpression gt ```

shikasd · Answer

Yeah I learned it from kotlinx serialiaztion long time ago

shikasd · Answer

Unfortunately toString doesn t work well with those

shikasd · Answer

< mattmoore> Updated my PR now all tests pass No need for a todo property anymore I decided to create them on the fly kinda like compose does so I could keep track of which `component` function to call Also it now supports other expressions as captured params so test const strings work correctly as well To achieve that I have written a simple transform which basically converts `case Person Matt Moore ` into `subject is Person amp amp subject component1 == Matt amp amp subject component2 == Moore `

mattmoore · Answer

This looks great I merged your PR

raulraja · Answer

awesome stuff < shikasd> clap

raulraja · Answer

Some of those component methods are unsafe in the std lib and would cause the pattern to blow up

raulraja · Answer

like destructuring a list

raulraja · Answer

that is empty We need to ensure the desugaring is safe in those cases because a user always expect the match to be a partial function This is why unapply in Scala returns an Option tupled

raulraja · Answer

that is if any of those result in the match results on an exception by invoking componentN it needs to go towards false in the desugar in such a way that it does not blow up

raulraja · Answer

ideally it detects if it s a data class then it s safe to not try catch

raulraja · Answer

but any component1 declared in interfaces have to be safe wrapped and non fatal exceptions coerced to false or the cases won t form partial functions

shikasd · Answer

For now I check if the call is constructor for class I think ideally I would check if parameters of constructor have a corresponding property so probably we could extend support to more than just data classes But in general I think supporting only them is fine