Top-level expressions cannot be parsed

[keynmol]

Commit of tree-sitter-scala you tested this on

HEAD

A code sample showing the error

test-plugins.sbt

addSbtPlugin("com.indoorvivants.vcpkg" % "sbt-vcpkg-native" % "0.0.11")
// hello

Show the error node

Run with npm exec -- tree-sitter parse test-plugins.sbt

(compilation_unit [0, 0] - [2, 0]
  (ERROR [0, 0] - [2, 0]
    (comment [1, 0] - [1, 8])))
test-plugins.sbt        0 ms    (ERROR [0, 0] - [2, 0])

What do you expect the tree to look like

Correctly parsed

Where are you experiencing this error?

No response

---

Notes

This is technically not valid Scala, you can't have top level expressions:

val x = 25
println(x)

@main def hello = ???

Compiling project (Scala 3.2.0, JVM)
[error] ./test.scala:2:1: Illegal start of toplevel definition
[error] println(x)
[error] ^^^^^^^
Error compiling project (Scala 3.2.0, JVM)
Compilation failed

But it's valid in the context of SBT.

@olafurpg patched it in Sourcegraph's fork, but that breaks most tests: sourcegraph@6cd3cb6 so we will likely need to rejig other parts of the grammar.

The question of whether we allow it unconditionally is open, but for the purposes of syntax highlighting IMO we should.

[bishabosha]

I think given scala script files with scala-cli are now SIP approved, this is certainly more critical

[susliko]

I took a look at the test suite errors arising from including $.expression into $._top_level_definition. It seems, that roughly a half of them are related to the left-associativity of class/object/trait definition (introduced in #102 in order to miminize memory usage). For example

class Foo() {}

is parsed as

(compilation_unit [0, 0] - [2, 0]
  (class_definition [0, 0] - [0, 11]
    name: (identifier [0, 6] - [0, 9])
    class_parameters: (class_parameters [0, 9] - [0, 11]))
  (block [0, 12] - [0, 14]))

(Now $.block is a valid top-level node as a part of $._simple_expression)

@eed3si9n fyi