Description Jurgen Vinju 2011-03-17 08:22:35 EDT

Created attachment 191407 [details]
A patch for imp.runtime, relative to the project.

The following patch introduces a new IMP language service: "annotator". 
  * An annotator is an ast processor that may quickly modify an ast. 
  * Annotators are run just after parsing, but before the other editor services are run. This allows these services to use information provided by the annotator.
  * Annotators are given an IMessageHandler so as to be able to put error markers in an editor

The last point is the critical functionality. Normal editor services are not able to do this due to race conditions. The explanation is that ParserSchedular is run as an asyncronous job. Eclipse does not guarantee that each call to run() is executed in order, so a language service can NOT by itself manage editor annotations (a previous run may throw away the markers that the next run is just adding).

The second point is interesting, but can currently not be implemented safely. The reason is that the ast reference is stored in the parse controller. The client is therefore responsible for managing the state of the ast. The functionality of passing the result of annotating to other language services can not be implemented safely by IMP. I recommend changing this, but I'll file another report.

This patch also includes a number of clean up operations in ParserSchedular. Out-of-date comments where removed as well as some superfluous comments. Also, some dead code was removed regarding the "level" of analysis that is needed. More simplification is possible here. We should design real system for staging language services and remove the current code.