Typing is slow when worksheet contains huge mixin composition

scala-ide / scala-worksheet

A Scala IDE plugin for a multi-line REPL (called worksheet)

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Typing is slow when worksheet contains huge mixin composition #186

Open Blaisorblade opened 10 years ago

Blaisorblade commented 10 years ago

Typing in the worksheet (with Scala-IDE 3.0.3) is painfully slow for me — as in, slower than typing over SSH. It was not like this, but I can't pin down when this changed. Might be related to #112, but I can't really tell.

Blaisorblade commented 10 years ago

Aaah, figured it out! The worksheet in question contains a line composing almost all mixins for my whole project together.

Moving that line to a method in a separate trait (EDIT: done in inc-lc/ilc-scala@10beab849b5fec3a04b17bea87ed2fa31c147021) makes things much faster — both typing and evaluation of subsequent lines.

It seems more plausible that #112 is involved.

dragos commented 10 years ago

This is most likely a performance problem in the type-checker, and your workaround is a good solution. Another few options:

add an explicit type to val v =. I believe the type-checker builds a complicated refinement type for that val, every time you type
upgrade to Scala 2.11.1+, where we have several improvements to the type-checker.