deprecate all useless tag methods, implement Find() and friends.

tags.go

@@ -9,18 +9,8 @@ import (
 
 type Tag []string
 
-// StartsWith checks if a tag contains a prefix.
-// for example,
-//
-//	["p", "abcdef...", "wss://relay.com"]
-//
-// would match against
-//
-//	["p", "abcdef..."]
-//
-// or even
-//
-//	["p", "abcdef...", "wss://"]
+// Deprecated: this is too cumbersome for no reason when what we actually want is
+// the simpler logic present in Find and FindWithValue.
 func (tag Tag) StartsWith(prefix []string) bool {
 	prefixLen := len(prefix)
 
@@ -37,6 +27,7 @@ func (tag Tag) StartsWith(prefix []string) bool {
 	return strings.HasPrefix(tag[prefixLen-1], prefix[prefixLen-1])
 }
 
+// Deprecated: write these inline instead
 func (tag Tag) Key() string {
 	if len(tag) > 0 {
 		return tag[0]
@@ -44,6 +35,7 @@ func (tag Tag) Key() string {
 	return ""
 }
 
+// Deprecated: write these inline instead
 func (tag Tag) Value() string {
 	if len(tag) > 1 {
 		return tag[1]
@@ -51,6 +43,7 @@ func (tag Tag) Value() string {
 	return ""
 }
 
+// Deprecated: write these inline instead
 func (tag Tag) Relay() string {
 	if len(tag) > 2 && (tag[0] == "e" || tag[0] == "p") {
 		return NormalizeURL(tag[2])
@@ -70,7 +63,7 @@ func (tags Tags) GetD() string {
 	return ""
 }
 
-// GetFirst gets the first tag in tags that matches the prefix, see [Tag.StartsWith]
+// Deprecated: use Find or FindWithValue instead
 func (tags Tags) GetFirst(tagPrefix []string) *Tag {
 	for _, v := range tags {
 		if v.StartsWith(tagPrefix) {
@@ -80,7 +73,7 @@ func (tags Tags) GetFirst(tagPrefix []string) *Tag {
 	return nil
 }
 
-// GetLast gets the last tag in tags that matches the prefix, see [Tag.StartsWith]
+// Deprecated: use FindLast or FindLastWithValue instead
 func (tags Tags) GetLast(tagPrefix []string) *Tag {
 	for i := len(tags) - 1; i >= 0; i-- {
 		v := tags[i]
@@ -91,7 +84,7 @@ func (tags Tags) GetLast(tagPrefix []string) *Tag {
 	return nil
 }
 
-// GetAll gets all the tags that match the prefix, see [Tag.StartsWith]
+// Deprecated: use FindAll instead
 func (tags Tags) GetAll(tagPrefix []string) Tags {
 	result := make(Tags, 0, len(tags))
 	for _, v := range tags {
@@ -102,7 +95,7 @@ func (tags Tags) GetAll(tagPrefix []string) Tags {
 	return result
 }
 
-// All returns an iterator for all the tags that match the prefix, see [Tag.StartsWith]
+// Deprecated: use FindAll instead
 func (tags Tags) All(tagPrefix []string) iter.Seq2[int, Tag] {
 	return func(yield func(int, Tag) bool) {
 		for i, v := range tags {
@@ -115,7 +108,7 @@ func (tags Tags) All(tagPrefix []string) iter.Seq2[int, Tag] {
 	}
 }
 
-// FilterOut returns a new slice with only the elements that match the prefix, see [Tag.StartsWith]
+// Deprecated: this is useless, write your own
 func (tags Tags) FilterOut(tagPrefix []string) Tags {
 	filtered := make(Tags, 0, len(tags))
 	for _, v := range tags {
@@ -126,7 +119,7 @@ func (tags Tags) FilterOut(tagPrefix []string) Tags {
 	return filtered
 }
 
-// FilterOutInPlace removes all tags that match the prefix, but potentially reorders the tags in unpredictable ways, see [Tag.StartsWith]
+// Deprecated: this is useless, write your own
 func (tags *Tags) FilterOutInPlace(tagPrefix []string) {
 	for i := 0; i < len(*tags); i++ {
 		tag := (*tags)[i]
@@ -140,8 +133,7 @@ func (tags *Tags) FilterOutInPlace(tagPrefix []string) {
 	}
 }
 
-// AppendUnique appends a tag if it doesn't exist yet, otherwise does nothing.
-// the uniqueness comparison is done based only on the first 2 elements of the tag.
+// Deprecated: write your own instead with Find() and append()
 func (tags Tags) AppendUnique(tag Tag) Tags {
 	n := len(tag)
 	if n > 2 {
@@ -154,6 +146,49 @@ func (tags Tags) AppendUnique(tag Tag) Tags {
 	return tags
 }
 
+// Find returns the first tag with the given key/tagName that also has one value (i.e. at least 2 items)
+func (tags Tags) Find(key string) Tag {
+	for _, v := range tags {
+		if len(v) >= 2 && v[0] == key {
+			return v
+		}
+	}
+	return nil
+}
+
+// FindWithValue is like Find, but also checks if the value (the second item) matches
+func (tags Tags) FindWithValue(key, value string) Tag {
+	for _, v := range tags {
+		if len(v) >= 2 && v[1] == value && v[0] == key {
+			return v
+		}
+	}
+	return nil
+}
+
+// FindLast is like Find, but starts at the end
+func (tags Tags) FindLast(key string) Tag {
+	for i := len(tags) - 1; i >= 0; i-- {
+		v := tags[i]
+		if len(v) >= 2 && v[0] == key {
+			return v
+		}
+	}
+	return nil
+}
+
+// FindLastWithValue is like FindLast, but starts at the end
+func (tags Tags) FindLastWithValue(key, value string) Tag {
+	for i := len(tags) - 1; i >= 0; i-- {
+		v := tags[i]
+		if len(v) >= 2 && v[1] == value && v[0] == key {
+			return v
+		}
+	}
+	return nil
+}
+
+// this exists to satisfy Postgres and stuff and should probably be removed in the future since it's too specific
 func (t *Tags) Scan(src any) error {
 	var jtags []byte
 
@@ -187,30 +222,3 @@ func (tags Tags) ContainsAny(tagName string, values []string) bool {
 
 	return false
 }
-
-// Marshal Tag. Used for Serialization so string escaping should be as in RFC8259.
-func (tag Tag) marshalTo(dst []byte) []byte {
-	dst = append(dst, '[')
-	for i, s := range tag {
-		if i > 0 {
-			dst = append(dst, ',')
-		}
-		dst = escapeString(dst, s)
-	}
-	dst = append(dst, ']')
-	return dst
-}
-
-// MarshalTo appends the JSON encoded byte of Tags as [][]string to dst.
-// String escaping is as described in RFC8259.
-func (tags Tags) marshalTo(dst []byte) []byte {
-	dst = append(dst, '[')
-	for i, tag := range tags {
-		if i > 0 {
-			dst = append(dst, ',')
-		}
-		dst = tag.marshalTo(dst)
-	}
-	dst = append(dst, ']')
-	return dst
-}