diff --git a/cmd/install/install.go b/cmd/install/install.go
index cef11f0..8f8ce9f 100644
--- a/cmd/install/install.go
+++ b/cmd/install/install.go
@@ -10,6 +10,10 @@ type installer interface {
 	Uninstall(cmd, bin string) error
 }
 
+// Install complete command given:
+// cmd: is the command name
+// asRoot: if true the completion will be installed in /etc/bash_complete.d
+// otherwise the complete command will be added to the ~/.bashrc file.
 func Install(cmd string, asRoot bool) error {
 	bin, err := getBinaryPath()
 	if err != nil {
@@ -18,6 +22,10 @@ func Install(cmd string, asRoot bool) error {
 	return getInstaller(asRoot).Install(cmd, bin)
 }
 
+// Uninstall complete command given:
+// cmd: is the command name
+// asRoot: if true the completion will be removed from /etc/bash_complete.d
+// otherwise the complete command will be removed from the ~/.bashrc file.
 func Uninstall(cmd string, asRoot bool) error {
 	bin, err := getBinaryPath()
 	if err != nil {
diff --git a/match.go b/match.go
index 7593d65..8da8f2c 100644
--- a/match.go
+++ b/match.go
@@ -20,6 +20,7 @@ func (a MatchPrefix) String() string {
 	return string(a)
 }
 
+// Match returns true if a has the prefix as prefix
 func (a MatchPrefix) Match(prefix string) bool {
 	return strings.HasPrefix(string(a), prefix)
 }
@@ -32,6 +33,7 @@ func (a MatchFileName) String() string {
 	return string(a)
 }
 
+// Match returns true if prefix's abs path prefixes a's abs path
 func (a MatchFileName) Match(prefix string) bool {
 	full, err := filepath.Abs(string(a))
 	if err != nil {
diff --git a/predicate.go b/predicate.go
index a6746be..e377429 100644
--- a/predicate.go
+++ b/predicate.go
@@ -27,9 +27,9 @@ func (p Predicate) predict(last string) []Matcher {
 }
 
 // PredictNothing does not expect anything after.
-var PredictNothing Predicate = nil
+var PredictNothing Predicate
 
-// PredictNothing expects something, but nothing particular, such as a number
+// PredictAnything expects something, but nothing particular, such as a number
 // or arbitrary name.
 func PredictAnything(last string) []Matcher { return nil }