Error on Parser::parse when a file doesn't have expressions (max 3 lines)

[DrSensor]

Given this file then execute scrap code $file -f xstate:

3 lines empty.scl

will produce:

ERROR: can't parse
---
 --> examples/test.scl:3:1
  |
3 | 
  | ^---
  |
  = expected expression
---

3 lines with comment.scl

// A -> B @ Click
// A <-> B @ Toggle
// ->> B @ Click

will produce:

ERROR: can't parse
---
 --> examples/test.scl:3:17
  |
3 | // ->> B @ Click
  |                 ^---
  |
  = expected expression
---

end with with comment.scl

// A -> B @ Click

// ->> B @ Click

will produce:

ERROR: can't parse
---
 --> examples/test.scl:3:17
  |
3 | // ->> B @ Click
  |                 ^---
  |
  = expected expression
---

end with with empty line.scl

// A -> B @ Click
// ->> B @ Click

will produce:

ERROR: can't parse
---
 --> examples/test.scl:3:1
  |
3 | 
  | ^---
  |
  = expected expression
---