replace generic set implemetation with plain set (unstable in go1.19)

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

go.mod

@@ -31,7 +31,6 @@ require (
 	github.com/wagoodman/go-partybus v0.0.0-20200526224238-eb215533f07d
 	github.com/wagoodman/go-progress v0.0.0-20200621122631-1a2120f0695a
 	golang.org/x/crypto v0.0.0-20220315160706-3147a52a75dd
-	golang.org/x/exp v0.0.0-20230202163644-54bba9f4231b
 )
 
 require (

go.sum

@@ -866,8 +866,6 @@ golang.org/x/exp v0.0.0-20191227195350-da58074b4299/go.mod h1:2RIsYlXP63K8oxa1u0
 golang.org/x/exp v0.0.0-20200119233911-0405dc783f0a/go.mod h1:2RIsYlXP63K8oxa1u096TMicItID8zy7Y6sNkU49FU4=
 golang.org/x/exp v0.0.0-20200207192155-f17229e696bd/go.mod h1:J/WKrq2StrnmMY6+EHIKF9dgMWnmCNThgcyBT1FY9mM=
 golang.org/x/exp v0.0.0-20200224162631-6cc2880d07d6/go.mod h1:3jZMyOhIsHpP37uCMkUooju7aAi5cS1Q23tOzKc+0MU=
-golang.org/x/exp v0.0.0-20230202163644-54bba9f4231b h1:EqBVA+nNsObCwQoBEHy4wLU0pi7i8a4AL3pbItPdPkE=
-golang.org/x/exp v0.0.0-20230202163644-54bba9f4231b/go.mod h1:CxIveKay+FTh1D0yPZemJVgC/95VzuuOLq5Qi4xnoYc=
 golang.org/x/image v0.0.0-20190227222117-0694c2d4d067/go.mod h1:kZ7UVZpmo3dzQBMxlp+ypCbDeSB+sBbTgSJuh5dn5js=
 golang.org/x/image v0.0.0-20190802002840-cff245a6509b/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=

internal/string_set.go

@@ -0,0 +1,76 @@
+package internal
+
+import (
+	"sort"
+)
+
+type StringSet map[string]struct{}
+
+func NewStringSet(is ...string) StringSet {
+	// TODO: replace with single generic implementation that also incorporates other set implementations
+	s := make(StringSet)
+	s.Add(is...)
+	return s
+}
+
+func (s StringSet) Size() int {
+	return len(s)
+}
+
+func (s StringSet) Merge(other StringSet) {
+	for _, i := range other.List() {
+		s.Add(i)
+	}
+}
+
+func (s StringSet) Add(ids ...string) {
+	for _, i := range ids {
+		s[i] = struct{}{}
+	}
+}
+
+func (s StringSet) Remove(ids ...string) {
+	for _, i := range ids {
+		delete(s, i)
+	}
+}
+
+func (s StringSet) Contains(i string) bool {
+	_, ok := s[i]
+	return ok
+}
+
+func (s StringSet) Clear() {
+	// TODO: replace this with the new 'clear' keyword when it's available in go 1.20 or 1.21
+	for i := range s {
+		delete(s, i)
+	}
+}
+
+func (s StringSet) List() []string {
+	ret := make([]string, 0, len(s))
+	for i := range s {
+		ret = append(ret, i)
+	}
+	return ret
+}
+
+func (s StringSet) Sorted() []string {
+	ids := s.List()
+
+	sort.Slice(ids, func(i, j int) bool {
+		return ids[i] < ids[j]
+	})
+
+	return ids
+}
+
+func (s StringSet) ContainsAny(ids ...string) bool {
+	for _, i := range ids {
+		_, ok := s[i]
+		if ok {
+			return true
+		}
+	}
+	return false
+}