[Grace-core] Comments

[Michael Homer]

The specification says:
    Comments are _not_ treated as white-
    space. Each comment is conceptually attached to the smallest immediately
    preceding syntactic unit, except that comments following a blank line are
    attached to the largest immediately following syntactic unit.

Which is the attachment syntactic unit for each of the following comments?
    // comment
    1 + 2 // comment
    1 + // comment
        2
    x.y(1 // comment
        , 2)
    x.y(1, // comment
        2)
    x.y(1, // comment
             // comment2
          2)
    x.y(1 // comment
        , // comment2
        2)
    x.y(1

        // comment
        , 2)
    x.y // comment
        ( // comment2
            1
        ) // comment3
    -x // comment
    - // comment
        x // comment2
    1 + x.y // comment
    1 + x.y {} // comment
  method x(a // comment
        : String) {}
    method x(a : // comment
        String) {}
    method x(a : String // comment
        ) {}
    method x(a : String) // comment
        {}
    method x(a) -> // comment
        String {}
    method x(a) -> String // comment
        {}
    method x(a) // comment
        -> // comment2
        String // comment3
        {} // comment4
    method // comment
        x // comment2
        (a) // comment3
        {}
    x.y // comment
        (1) z(2)
    x.y(1) // comment
        z(2)
    x.y "" // comment
    x.y "" // comment
        z(2)
    x.y // comment
        "" // comment2
        z // comment3
        (2) // comment4
    x // comment
        .y // comment2
    x // comment
        . // comment2
        y // comment3
    x.y.z // comment
    x.y.z "" // comment

    // comment
    // comment2

    var x := 1 // comment
    var x := 1; // comment
    var x := // comment
        1
    var x // comment
        := 1
    var // comment
        x := 1
    var // comment
        x // comment2
        := // comment3
        1 // comment4
    var x : // comment
        Number := 1
    var x : String | Number // comment
      := 1
    if ( // comment
        true) then { // comment2
    }
    if (true) then {

        // comment
    }
    for (1..10) do { i -> // comment
    }
    for (1..10) do {
        i // comment
          // comment2
        -> // comment3
    }
    return 1 + 2 // comment
    return // comment
        1 + 2 // comment2

    // comment

Are any of those invalid comment locations? Is the attachment unit for
any of them outside the passage?
-Michael