[Nashorn] 文字列とConsString

function assertEq(f,x) {var r=f();if(r!==x)throw new Error(f.toSource()+", expected=${x}, actual=${r}");}

var JString = Java.type("java.lang.String");

var ConsString = Java.type("jdk.nashorn.internal.runtime.ConsString");

var s = "a";

assertEq(function() ("a" + "b").getClass(), JString.class);

assertEq(function() (s + "b").getClass(), ConsString.class);

s += 10;

assertEq(function() s.getClass(), ConsString.class);

print("done.");

>jjs -scripting -fullversion consString.js

nashorn full version 1.8.0_66-b18

done.

>jjs -scripting -fullversion

nashorn full version 1.8.0_66-b18

jjs> var s = "a"; print(s.class);

class java.lang.String

jjs> print((s + "b").class);

class java.lang.String

jjs> s += 10; print(s.class);

class java.lang.String