Question

How would you get the dreamed DRY ideal in this sample, in the language of your choice:

drawLine(Point(0, 0), Point(w, 0)); int curRowY = 0; for(int row=0; row<rowHeights.size(); row++) {     curRowY += rowHeights[row];     drawLine(Point(0, curRowY), Point(w, curRowY)); }  drawLine(Point(0, 0), Point(0, h)); int curColX = 0; for(int col=0; col<colWidths.size(); col++) {     curColX += colWidths[col];     drawLine(Point(curColX, 0), Point(curColX, h)); } 

Note: A multitude of ad-hoc preprocessor macros is likely to be extremely less readable&writable so that’s out.

Answer 1

The answer is simple: vectors. E.g.

repeatLines(Point start, Point end, Vector direction, int[] gaps)     {     drawLine(start, end);     for (int i = 0; i < gaps.Length; i++)         {         Vector vector = direction * gaps[i];         start += vector;         end += vector;         drawLine(start, end);         }     }  repeatLines(Point(0, 0), Point(0, w), Vector(1, 0), rowHeights); repeatLines(Point(0, 0), Point(h, 0), Vector(0, 1), colWidths);