lib/compiler/compiler.js
function ConcatStringList(outputs) {
  return outputs.length ? outputs.reduce(
    (prev, next) => t.binaryExpression('+', prev, next)
  ) : t.stringLiteral('');
}
function ConcatStringList(outputs) {
  return outputs.length ? outputs.reduce(
    (prev, next) => t.binaryExpression('+', prev, next)
  ) : t.stringLiteral('');
}
function ConcatStringList ( outputs ) { return outputs . length ? outputs . reduce ( ( prev , next ) => t . binaryExpression ( '+' , prev , next ) ) : t . stringLiteral ( '' ) ; }
take an array of string expressions and convert it to direct concatenation like this a + b + c + d
take an array of string expressions and convert it to direct concatenation like this a + b + c + d