CAT-scan a code-base

Structure101 v2 goes beta today. With it you can walk through the code-base in slices from the class-level, to the package-level and up through the design levels, spotting tangles and seeing how far they have spread.

This is a snag of the Slice perspective with the slice selector highlighted:

You can now see dependency graphs as matrices, which tend to be better for very large graphs (like slices). A value in a cell indicates a dependency from the column item to the row item. Here’s the equivallent of the tangle shown as a diagram above – as a matrix (highlighted) it now fits in on the screen:

And here is a much bigger slice of all the classes in the code-base grouped by parent package (the orange areas).

Even zoomed way out, it is possible to pick out some patterns on the matrix. The rows and columns are ordered so that as far as possible items only use items below or to the right, so any dots (dependencies) above the diagonal indicate cyclic dependencies. Horizontal lines indicate heavily used items, vertical lines indicate items that use a lot of other items.

Version 2 lets you “tag” (mark) code-level items (like methods and classes), and any higher-level item (like a package) that contains tagged items is shown as tagged. This lets you tag items in one slice and then see how it maps to other slices and hierarchies. For example, you could tag a big class-level tangle in the Slice perspective and then go to the Composition perspective to see how the tangle is distributed across the package design – it would look like this: