ant is an amazing build tool. I have been using ant for some time to build the java code that lives inside the src directories of my R packages, see this post for example.

The drawbacks of this approach are :

• that it assumes ant is available on the system that builds the package
• You cannot use R code within the ant build script

The ant package for R is developed to solve these two issues. The package is source-controlled in r-forge as part of the orchestra project

Once installed, you find an ant.R script in the exec directory of the package. This script is pretty similar to the usual shell script that starts ant, but it sets it so that it can use R with the following additional tasks

• <r-run> : to run arbitrary R code
• <r-set> : to set a property of the current project with the result of an R expression

Here is an example build file that demonstrate how to use these tasks

Here is what happens when we call the R special version of ant with this build script

$ `Rscript -e "cat( system.file( 'exec', 'ant.R', package = 'ant') )"`
Buildfile: build.xml

test:
     [echo] 
     [echo]     R home        : /usr/local/lib/R
     [echo]     R version     : R version 2.10.0 Under development (unstable) (2009-08-05 r49067)
     [echo]     rJava home    : /usr/local/lib/R/library/rJava
     [echo]     rJava version : 0.7-1
     [echo]  

BUILD SUCCESSFUL
Total time: 1 second