Re: Nashorn comment nodes in the syntax tree

[Sundararajan Athijegannathan]

Hi,

Yes, comments are swallowed (by design). But, I initially though that
disturbs line & column number info. [i.e., position of various trees].
i.e., that was the bug you reported. That does not seem to be the case.

I wrote a simple sample and checked with jjs in jdk9 build. You can
check start and end line/column numbers of subtrees (function,
expression statement) are correct.

Also, please note that jdk.nashorn.internal.* packages are not APIs and
therefore please avoid using those. Please use nashorn parser API
defined by JEP 236 [ http://openjdk.java.net/jeps/236 ]

#-scripting needed

var Parser = Java.type("jdk.nashorn.api.tree.Parser")
var p = Parser.create();
var cu = p.parse("t.js", <<EOF
/* start script comment */

  function hello(){
 return 'world';
}

//some comment
    hello();
EOF, print);

var src = cu.sourceElements;
var itr = src.iterator();
var lm = cu.lineMap;
while (itr.hasNext()) {
   var tree = itr.next();
   var start = tree.startPosition;
   var end = tree.endPosition;
   print(tree.kind,
     lm.getLineNumber(start),
     lm.getColumnNumber(start),
     lm.getLineNumber(end),
     lm.getColumnNumber(end));
}


Output:

FUNCTION 3 2 5 1
EXPRESSION_STATEMENT 8 4 8 11

PS. please check line & column w.r.t beginning of test script parsed.
i.e., the heredoc starting point.

-Sundar