code: function escapeToJs(ctx, jsescform, replacements) {
    var result;
    // note:  currently ~(js...) is the only thing supported with ~(...)
    if (Array.isArray(jsescform) && jsescform.length > 1 && jsescform[0].value === "js") {
      var jscodestr = sl.valueOfStr(jsescform[1]);
      // returns in the javascript code cause "Unexpected token ILLEGAL"
      jscodestr = jscodestr.replace(/\\n/g, "");
  
      // allow Function to work without error when CSP e.g. in Atom Preview
      // consider merging or replacing the below with one of the ctx.eval* calls
      if(ctx.options.transpile.csp) {
        require('loophole').allowUnsafeNewFunction(function() {
          var f = new Function("$args", "sl", "'use strict'; " + jscodestr);
          // note the evaluated javascript can see the replacements as normal variables
          result = f.call(replacements, replacements, sl);
        });
      }
      else {
        var f = new Function("$args", "sl", "'use strict'; " + jscodestr);
        // note the evaluated javascript can see the replacements as normal variables
        result = f.call(replacements, replacements, sl);
      }
    }
    return result;
  }
docs: Escape out and run some javascript at macro expansion time
  You embed the javascript in ~(js "<javascript code here>") in the macro body
  note:  this was added prior to the addition of template strings.  That and/or
  the addition of quasiquote may make this feature unnecessary in the future.