Yeah, but whereas git and other version control systems are great with lines of code - and diff works well on that - for text we need a diff that works on lexic

Yeah, but whereas git and other version control systems are great with lines of code - and diff works well on that - for text we need a diff that works on lexical units within a (much longer) line or structure. I know git can be configured to use an arbritary programme for diff - just not sure where to find one...