1 files changed, 49 insertions, 0 deletions
diff --git a/cmd/filter.go b/cmd/filter.go
new file mode 100644
index 0000000..9d8ccac
--- /dev/null
+++ b/cmd/filter.go
@@ -0,0 +1,49 @@
+package cmd
+
+import (
+	"fmt"
+)
+
+type Filter struct {
+	name       string
+	action     func(string) string
+	subfilters []Filter
+}
+
+type Greeter interface {
+	Greet()
+}
+
+type Filterer interface {
+	Greeter
+	Filter(string) string
+}
+
+func (f Filter) Greet() {
+	subfilterCount := len(f.subfilters)
+
+	fmt.Printf("I am a filter and my name is %v\n", f.name)
+	if subfilterCount > 0 {
+		fmt.Println("My subfilters are:")
+
+		for _, subfilter := range f.subfilters {
+			fmt.Printf("- %v\n", subfilter.name)
+		}
+	}
+}
+
+func (f Filter) Filter(token string) (modifiedToken string) {
+	subfilterCount := len(f.subfilters)
+	modifiedToken = token
+
+	if subfilterCount > 0 {
+		for _, subfilter := range f.subfilters {
+			modifiedToken = subfilter.action(modifiedToken)
+		}
+
+		return modifiedToken
+	}
+
+	modifiedToken = f.action(token)
+	return modifiedToken
+}