interfaces: refactor

interfaces/05-log-parser/refactor-notes/refactor-02/changes.md

@@ -0,0 +1,20 @@
+### PROBLEM
++ `summarize()` knows a lot about the internals of the `parser`.
+  + coupled to the `parser`.
+
+## SOLUTION
++ remove: `parser.go` `sum` and `domains` fields
+  + remove: `parser.go/newParser()`
+  + change: `parser.go/parse(p *parser) error` -> `parse() ([]result, error)`
+  + initialize: `sum` inside `parse()`
+  + remove: `update()`
+  + call: `sum` update in the `parse()`
+  + collect the grouped results and return them from `parser()`
+
++ `summarize(p *parser)` -> `summarize([]result)`
++ in `summarize()`
+  + `sort.Slice`
+  + range over `[]result`
+
++ `main.go`
+  + just: `res, err := parse()`