pub fn build_fragmap(commit_diffs: &[CommitDiff], deduplicate: bool) -> FragMapExpand description
Build a fragmap from a collection of commits and their diffs.
Implements the Span Propagation Graph (SPG) algorithm from the original fragmap tool. For each file, a DAG is built where active nodes (hunks) and inactive nodes (propagated surviving spans) are connected by overlap edges. Columns correspond to unique paths through the DAG, with each path’s active nodes determining which commits have CHANGE in that column. Build a fragmap from a list of commit diffs.
When deduplicate is true (the normal view), columns whose set of touching
commits is identical are merged into one, producing a compact matrix. Pass
false to keep every raw hunk cluster as its own column, which is useful
for debugging the cluster layout.