Parens: ${(…; …)} & multiline expr handling

[brianrourkeboll]

Another followup to #16079.

Description

• Keep parens around sequential exprs in interpolated strings.

  Source

  $"{((); ())}"

  Before

  $"{(); ()}"// error FS0010: Unexpected symbol ';' in interaction. Expected interpolated string (final part), interpolated string (part) or other token.

  After

  $"{((); ())}"

• Handle more multiline parenthesization scenarios.

  The snipping tool is not working for me right now for some reason, but here is an example of the kind of multiline parenthesized expression that is now handled correctly:

  Source

  let_=letx=3(lety=99
  y - x
  )

  Before

  let_=letx=3lety=99
  y - x
  // error FS0010: Unexpected keyword 'let' or 'use' in binding. Expected incomplete structured construct at or before this point or other token.

  After

  let_=letx=3lety=99
  y - x

  I also introduced some new logic to handle scenarios like the following, where removing the parentheses would result in outer bindings being shadowed, e.g.:

  let_=letx=1lety=2(lety=-2
  printfn $"{y}")
  x + y // y is 2 here; it would become -2 if we removed the parens, so we must keep them.

• Trim extra whitespace between the parens and the inner constructs, e.g.:

  let_=(3)

  →

  let_=3

Checklist

• Test cases added.
• Release notes entry updated.

Notes

@nojaf I moved the innards of the ParsedInput module from #16462 into a SyntaxNodes module, exposed only internally for now. The ParsedInput module now simply delegates to that.

bba8e2a shows an example of the "composability" that I was trying to gesture at before.

[github-actions]

❗ Release notes required

---

✅ Found changes and release notes in following paths:

Change path	Release notes path	Description
src/Compiler	docs/release-notes/.FSharp.Compiler.Service/8.0.300.md
vsintegration/src	docs/release-notes/.VisualStudio/17.10.md

[T-Gro]

For an internal module, this is exceptionally well detailed API description, thank you

Does this issue actually repro?

[abonie]

Hey, how do I repro this? Tried the code and it does not cause any issues?

[brianrourkeboll]

@abonie

Hey, how do I repro this? Tried the code and it does not cause any issues?

With an extension built from the current main (and probably also in the latest VS preview), if you have the unnecessary parentheses code fix enabled, it should offer to remove the parens in these examples:

$"{((); ())}"

let_=letx=3(lety=99
y - x
)

but the resulting code will be invalid.

[brianrourkeboll]

@T-Gro

For an internal module, this is exceptionally well detailed API description, thank you

It's just a copy of the docs for the public ParsedInput module, which is now essentially just a wrapper for the SyntaxNodes one :)

[abonie]

My bad, didn't have it enabled, thanks for explaining :)

[psfinaki]

Great stuff, as usual :)