[GROOVY-6229] Some minor changes required regarding unary overloading operators and numbers

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: groovy-runtime
• Assignee: Unassigned
• Reporter: Paul King
• Created: 02/Jul/13 08:11
• Updated: 07/Apr/15 19:06

Description

There are some minor discrepancies in how Groovy is dealing with overloading for unaryMinus and unaryPlus with numbers. Here is one example:

class IntCat {
  static unaryPlus(Integer i) {"P"}
  static unaryMinus(Integer i) {"M"}
}
use (IntCat) {
  println 1.unaryPlus()   // => P
  println 1.unaryMinus()  // => M
  println (+1)            // => 1
  println (-1)            // => -1
}

We either need to not bypass operator overriding or document the reasons why we want a special case here.

And here is another:

println 1.unaryMinus()  // => -1
println 1.unaryPlus()   // => MME unaryPlus

We should provide the same hook for both (or potentially not provide this for either and provide documentation to justify why a special case would be needed).

Note also that it is a little strange for Strings too.

def foo = 'foo'
println (-foo)   // => MME negative
println (+foo)   // => MME positive