nashorn JS: execute AST string?

Given a string that represents a Nashorn AST, can that string then be executed

In JDK 8, an AST can be obtained by calling parse(String) using load("nashorn:parser.js"), how would one do the reverse: AST to execution?

Solution

You've to write your own AST to pretty printer converter for AST returned by JDK8's parser.js.

Note that there is a Java Parser API in jdk9 (https://docs.oracle.com/javase/9/docs/api/jdk/nashorn/api/tree/class-use/Parser.html). For the AST from this parser, there is a "pretty printer" sample script here: