Improved documentation

src/compiler/Scan.go

@@ -12,7 +12,7 @@ import (
 
 // Scan scans the directory.
 func Scan(path string) (<-chan *Function, <-chan error) {
-	functions := make(chan *Function, 16)
+	functions := make(chan *Function)
 	errors := make(chan error)
 
 	go func() {

src/errors/InvalidDirectory.go

@@ -7,6 +7,7 @@ type InvalidDirectory struct {
 	Path string
 }
 
+// Error implements the text representation.
 func (err *InvalidDirectory) Error() string {
 	if err.Path == "" {
 		return "Invalid directory"