title: Do any R IDEs support conditional breakpoints?
body: <p>Which, if any, R IDEs (e.g. StatET, Revolution R, RStudio, ESS, NppToR, others) support conditional breakpoints?</p>
  
  <p>This is available via <code>bp</code> in the <code>debug</code> package, or via an additional bit of code that invokes <code>browser()</code> based on a condition.  However, it can be more efficient to be able to toggle a particular line # and quickly enter a conditional breakpoint for that particular line, without having additional code or console activities.</p>
  
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  <p>Note 1.  I've searched a bit for these, and it seems that conditional breakpoints are not available in RStudio, and I think the same may be true for StatET.  There appears to be support in ESS (see <a href="http://code.google.com/p/ess-tracebug/#Conditional_Breakpoints" rel="noreferrer">this page</a>), though I'm not yet familiar with ess-tracebug and whether it's easy to use.  It also seems that this works only for older versions of ESS; I'm not yet familiar with functionality for more recent versions.</p>
  
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  <p>Update 1. I'm selecting an answer (the only one - Andrie's).  The question was answerable regarding whether <em>any</em> IDE supports conditional breakpoints, and, fortunately, Andrie has demonstrated that there exists a solution.  I remain interested in any other IDEs that support this, though Eclipse is good enough for now.  (At the moment, I prefer Rstudio, but this is already in their feature request list.)  If anyone has expertise in ESS and can demonstrate that functionality, I'm sure it will benefit others who happen upon this question.</p>