Reduce visit recursion for large binary expressions?

[dsherret]

Describe the feature

In certain transforms, it might be good to not use recursion. For example, it's fairly common for people to write code like the following:

const data = "AAEAAAASAQAABAAgR0RFRrRCsIIAAir4AAACYkdQT1Or8IZpAAItXAAAZS5H" +
  "U1VCeoGFdwACkowAABWQT1MvMpl2sYAAAhh4AAAAYGNtYXDG7lFtAAId8AAA" +
  "....etc for many many lines...";

It might be good for transforms like the resolver to special case these scenarios in its transformers and instead of visiting the expressions recursively it could visit them one by one in a loop so that it doesn't overflow the stack.

Babel plugin or link to the feature description

No response

Additional context

https://github.com/denoland/deno/issues/24325#issuecomment-2203867362

[kdy1]

Are you fine with a solution based on stacker? (Dynamically sized stacks) It's a general solution so it can be applied to any visitor quickly, but it may not work on some platforms.

Also, can you list the SWC passes used by Deno? IIRC, I added an in-tree testing for transforms used by a team, but I'm not sure if it was Deno or Parcel. I'll add one more in-tree test suite for it and for stack size.

[mischnic]

An older issue for the same problem: https://github.com/swc-project/swc/issues/1627

[dsherret]

Also, can you list the SWC passes used by Deno? IIRC, I added an in-tree testing for transforms used by a team, but I'm not sure if it was Deno or Parcel. I'll add one more in-tree test suite for it and for stack size.

Nope, wasn't us.

Are you fine with a solution based on stacker? (Dynamically sized stacks) It's a general solution so it can be applied to any visitor quickly, but it may not work on some platforms.

I think it's good to use stacker generally, but I feel like scenarios like this could be optimized to not use so much stack? It will probably run a lot faster.

Also, can you list the SWC passes used by Deno?

let mut passes = chain!(
    resolver(unresolved_mark, top_level_mark, true),
    proposal::decorator_2022_03::decorator_2022_03(),
    proposal::explicit_resource_management::explicit_resource_management(),
    helpers::inject_helpers(top_level_mark),
    typescript::typescript(typescript::Config {
      verbatim_module_syntax: false,
      import_not_used_as_values: typescript::ImportsNotUsedAsValues::Remove,
      no_empty_export: true,
      import_export_assign_config: typescript::TsImportExportAssignConfig::Preserve,
      ts_enum_is_mutable: true,
    }, top_level_mark),
    fixer(Some(comments)),
    hygiene(),
);

[kdy1]

Did you enable swc_ecma_utils/stacker? All of those passes should already have dynamic stack size support.

[kdy1]

Deno isn't using it. https://github.com/denoland/deno/blob/147411e64b22fe74cb258125acab83f9182c9f81/Cargo.lock#L6544-L6561

It should have stacker entry if it's enabled.