Debugging Nu Programs

Here are a few tips that can make it easier to find and fix problems in Nu programs.

  • First, it's a good idea when working with any dynamic language to write in small bits and test frequently.
  • Use the embedded console to explore and interact with objects. You can also use it to reload code into a running application. This allows you to build and test your code incrementally.
  • Use nush from the terminal to explore.
  • Debug crashes with gdb. From the gdb console, you can say things like po [object stringValue] to see a string representation of a Nu object. You can use that to see the Nu code that is being evaluated. You can also send other Objective-C messages from within gdb. For example, to see the contents of an NSDictionary, use po [dictionary description].