expand variable lists with prefix/suffix elements

lib/rscons/environment.rb

@@ -55,7 +55,16 @@ module Rscons
             expand_varref.call(ent)
           end
         else
-          if varref[0] == '$'
+          if varref =~ /^(.*)\$\[(\w+)\](.*)$/
+            # expand array with given prefix, suffix
+            prefix, varname, suffix = $1, $2, $3
+            varval = merged_variables[varname]
+            unless varval.is_a?(Array)
+              raise "Array expected for $#{varname}"
+            end
+            varval.map {|e| "#{prefix}#{e}#{suffix}"}
+          elsif varref[0] == '$'
+            # expand a single variable reference
             varname = varref[1, varref.size]
             varval = merged_variables[varname]
             if varval