fix golint issues in core/stringx (#516)

core/stringx/trie.go

@@ -5,8 +5,10 @@ import "github.com/tal-tech/go-zero/core/lang"
 const defaultMask = '*'
 
 type (
+	// TrieOption defines the method to customize a Trie.
 	TrieOption func(trie *trieNode)
 
+	// A Trie is a tree implementation that used to find elements rapidly.
 	Trie interface {
 		Filter(text string) (string, []string, bool)
 		FindKeywords(text string) []string
@@ -23,6 +25,7 @@ type (
 	}
 )
 
+// NewTrie returns a Trie.
 func NewTrie(words []string, opts ...TrieOption) Trie {
 	n := new(trieNode)
 
@@ -130,6 +133,7 @@ func (n *trieNode) replaceWithAsterisk(chars []rune, start, stop int) {
 	}
 }
 
+// WithMask customizes a Trie with keywords masked as given mask char.
 func WithMask(mask rune) TrieOption {
 	return func(n *trieNode) {
 		n.mask = mask