Perform parser optimizations in production mode

[msujew]

Closes #1687

Improves the production mode setting for the langium CLI. It's now generated into the language meta data and is used to skip validations and ignore ambiguity issues in the parser if activated.

This should improve the startup time of all grammars and is quite noticeable on larger grammars.

[aabounegm]

Looks good, but as I understand, this needs to be explicitly configured in langium-config.json, right?
Perhaps it is possible to add a default value in loadConfig like so?

config.mode ??= process.env.NODE_ENV ?? 'development';

Such that warnings would be present in dev mode (running with npm run langium:watch), but not in the production build

[msujew]

@aabounegm Thanks for taking a look!

Looks good, but as I understand, this needs to be explicitly configured in langium-config.json, right?

You can also use the --mode=production CLI argument to switch between development and production mode. I'm not a big fan of using env variables for that.

[aabounegm]

Ok that makes sense, I wasn't aware of the CLI option. In that case, maybe there should be an explicit --mode=production in the langium:generate scripts?

[msujew]

There already is:

langium/packages/langium/package.json

Line 62 in 335f9a9

"langium:generate:production": "langium generate --mode=production",

It's invoked before publishing the Langium artifacts.

[aabounegm]

Sorry, I meant in the template so that new projects would make use of it

[spoenemann]

How would we handle this when we publish the npm packages and vscode extension? Shall we re-generate the grammar language with production mode before publishing?

[spoenemann]

Oh I see, that's what we already do:

langium/.github/workflows/publish.yml

Line 28 in 335f9a9

npm run langium:generate:production --workspace=langium

It's a bit strange to change a generated file that is also in version control during the release process, but this is likely the most pragmatic solution for now.

[cdietrich]

@msujew will there a preview/alpha available for this feature

[msujew]

@cdietrich I can release one after tomorrow's dev meeting. I'll let you know.