The rendering is actually produced by InvokerHelper: https://github.com/apache/groovy/blob/master/src/main/org/codehaus/groovy/runtime/InvokerHelper.java#L123 <https://github.com/apache/groovy/blob/master/src/main/org/codehaus/groovy/runtime/InvokerHelper.java#L123>
I tried overriding it with a category and also via the metaClass, but neither worked. I recall some kind of trick that’s needed when using the metaClass with some classes, to get it to take, but I don’t remember the details. :( > On May 26, 2016, at 2:06 PM, Paolo Di Tommaso <[email protected]> > wrote: > > Dear all, > > I have a use case in which I need to override the `toString` method of a > custom List class and use it when interpolating that list object in a > GString. > > It turns out the Groovy uses its own formatting methods for List and other > structures, so the my custom `toString` is simply ignored. > > To explain it better take in consideration this example: > > class MyList extends ArrayList { > > String toString() { > this.join('-') > } > > } > > > def x = new MyList() > x << 1 << 2 << 3 > > assert x.toString() == '1-2-3' > assert "$x" == '1-2-3' > > Assertion failed: > assert "$x" == '1-2-3' > | | > | false > [1, 2, 3] > > The second assertion fails for the reason said above. Now I'm wondering it > there's any way to override somehow the GString default rendering mechanism > in such a way I can inject my own formatting rule for my custom class. > > Any suggestion is appreciated. > > > > Cheers, > Paolo > > >
