CRISPR performs pattern matching on the DNA sequence immediately preceding the cut location where new sequences are added. While we have had CTRL-X and CTRL-V for awhile (in the other gene modification techniques you alluded to) CRISPR provides a cursor that allows us to precisely control where the CTRL-V takes place.
As for updating "live" code...that's a flawed, but not completely wrong analogy. Other techniques do rely on modifying the genome before "production", and in that sense CRISPR does enable us to edit DNA in cases that would have been impractical before, but it still basically requires performing the modification on each cell individually -- so there are still practical limits on deploying the technique.
As for updating "live" code...that's a flawed, but not completely wrong analogy. Other techniques do rely on modifying the genome before "production", and in that sense CRISPR does enable us to edit DNA in cases that would have been impractical before, but it still basically requires performing the modification on each cell individually -- so there are still practical limits on deploying the technique.