CODEWITHSUNDEEP
rascal
josh
josh

Reputation: 1554

Rascal slow at importing modules

I am running Rascal from the REPL and it seems like it takes a pretty long time to import some modules. For example import lang::java::\syntax::Java15; takes seconds to run.

I've also noticed cases where modules that depend on other modules don't appear to be reloaded if they are changed. For example:

program 1:

module A::A
....

program 2:

module B::B
import A::A;
...

REPL:

import A::A;
import B::B;

Now I've made some changes to A and B and I import B again. I would imagine the changes to A would get propagated to the new version of B (since it is importing A) but this doesn't seem to happen.

  1. Why is importing this slow and is there a way to speed this up?
  2. How does importing packages with dependencies in the REPL work?

Thanks!

Upvotes: 0

Views: 103

Answers (1)

Jurgen Vinju
Jurgen Vinju

Reputation: 6696

We recently changed quite a bit about this part of the implementation. So could you tell us which version you are using?

Importing is slow right now because we have a bottleneck in the parsing infrastructure, as far as I can remember. Speeding it up; you can do by not using a console in Debug mode (i.e. use Run As...), using more memory for Eclipse also helps (I use 1.8Gb heap and an 80mb stack).

The REPL works in Eclipse by monitoring which modules have changed since running the previous command on the REPL. When a new command is entered, such as an import command, first all modules which have changed and the modules they depend on are purged, this produces an initial worklist for reloading, which is then executed in a fixpoint fashion to load the new modules (each module only once), then finally the command is executed.

Upvotes: 1

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