[Wilfred]

FWIW VCS for Smalltalk basically does this.

The challenge for a tool like difftastic is that I can't guarantee that syntax is well-formed. You might be using new syntax that my parser doesn't support, you might have merge conflicts, or you might have a plain syntax error in your code.

Tree-sitter handles parse errors gracefully, so difftastic handles syntax errors pretty well in my experience.