interfaces: refactor

interfaces/05-log-parser/refactor-notes/refactor-03-deprecated/changes.md

@@ -0,0 +1,14 @@
+### PROBLEM
++ `parser.go/parse()` also does updating. back to square one.
+  + we need to extract the reusable behavior: scanning.
+
++ inflexible:
+  + adding a filter is hard. needs to change the `scan()` code.
+  + adding a grouper is also hard. domain grouping is hardcoded.
+
+## SOLUTION
++ 
+
+## IDEAS:
+
++ make domain filter accept variadic args