add TokenizeColumns function

src/utils/lineFileUtilities/lineFileUtilities.h

@@ -46,5 +46,40 @@ void Tokenize(const string &str, vector<int> &elems, char delimiter = '\t')
     }
 }
 
+// tokenize a column string into a list of integers.
+inline
+void TokenizeColumns(const string &str, vector<int> &elems) 
+{
+
+    // http://stackoverflow.com/questions/236129/how-to-split-a-string-in-c/236803#236803
+    // NOTE: this approach intentionally allows consecutive delimiters
+    vector<string> col_sets;
+    Tokenize(str, col_sets, ',');
+
+    for( size_t i = 0; i < col_sets.size(); i++ ) {
+        string col_set = col_sets[i];
+        if( string::npos == col_set.find("-") ){
+            elems.push_back(atoi(col_set.c_str()));
+        }
+        else {
+            vector<string> ends;
+            Tokenize(col_set, ends, '-');
+            int start = atoi(ends[0].c_str());
+            int end = atoi(ends[1].c_str());
+            if(start <= end){
+                for(int i = start; i <= end; i++){
+                    elems.push_back(i);
+                }
+            }
+            else {
+                for(int i = start; i >= end; i--){
+                    elems.push_back(i);
+                }
+            } 
+        }
+    }
+}
+
+
 #endif /* LINEFILEUTILITIES_H */