Add refactored filter

filter/filter.go

@@ -1,31 +1,11 @@
-// Copyright 2022 Robert S. Muhlestein.
-// SPDX-License-Identifier: Apache-2.0
-
 package filter
 
 import (
-	"fmt"
-	"sort"
 	"strings"
 )
 
-// Number combines the primitives generally considered numbers by JSON
-// and other high-level structure data representations.
-type Number interface {
-	int16 | int32 | int64 | float32 | float64
-}
-
-// Text combines byte slice and string.
 type Text interface {
-	[]byte | string
-}
-
-// P is for "principle" in this case. These are the types that have
-// representations in JSON and other high-level structured data
-// representations.
-type P interface {
-	int16 | int32 | int64 | float32 | float64 |
-		[]byte | string | bool
+	string | []byte
 }
 
 // HasPrefix filters the Text input set and returns only those elements
@@ -39,48 +19,3 @@ func HasPrefix[T Text](set []T, pre string) []T {
 	}
 	return m
 }
-
-// Minus performs a set "minus" operation by returning a new set with
-// the elements of the second set removed from it.
-func Minus[T Text, M Text](set []T, min []M) []T {
-	m := []T{}
-	for _, i := range set {
-		var seen bool
-		for _, n := range min {
-			if string(n) == string(i) {
-				seen = true
-				break
-			}
-		}
-		if !seen {
-			m = append(m, i)
-		}
-	}
-	return m
-}
-
-// Println prints ever element of the set.
-func Println[T P](set []T) {
-	for _, i := range set {
-		fmt.Println(i)
-	}
-}
-
-// Keys returns the keys in lexicographically sorted order.
-func Keys[T any](m map[string]T) []string {
-	keys := []string{}
-	for k, _ := range m {
-		keys = append(keys, k)
-		sort.Strings(keys)
-	}
-	return keys
-}
-
-// Prefix returns a new slice with prefix added to each string.
-func Prefix(in []string, pre string) []string {
-	list := []string{}
-	for _, i := range in {
-		list = append(list, pre+i)
-	}
-	return list
-}

filter/filter_test.go

@@ -17,42 +17,3 @@ func ExampleHasPrefix() {
 	// Output:
 	// [two three]
 }
-
-func ExampleMinus() {
-	set := []string{
-		"one", "two", "three", "four", "five", "six", "seven",
-	}
-	fmt.Println(filter.Minus(set, []string{"two", "four", "six"}))
-	// Output:
-	// [one three five seven]
-}
-
-func ExamplePrintln() {
-	set := []string{"doe", "ray", "mi"}
-	filter.Println(set)
-	bools := []bool{false, true, true}
-	filter.Println(bools)
-	// Output:
-	// doe
-	// ray
-	// mi
-	// false
-	// true
-	// true
-}
-
-func ExampleKeys() {
-	m1 := map[string]int{"two": 2, "three": 3, "one": 1}
-	m2 := map[string]string{"two": "two", "three": "three", "one": "one"}
-	fmt.Println(filter.Keys(m1))
-	fmt.Println(filter.Keys(m2))
-	// Output:
-	// [one three two]
-	// [one three two]
-}
-
-func ExamplePrefix() {
-	fmt.Println(filter.Prefix([]string{"foo", "bar"}, "my"))
-	// Output:
-	// [myfoo mybar]
-}