1 files changed, 39 insertions, 7 deletions
diff --git a/error.go b/error.go
index b5302ad..519309f 100644
--- a/error.go
+++ b/error.go
@@ -1,20 +1,52 @@
 package bolt
 
 var (
-	InvalidError               = &Error{"Invalid database", nil}
-	VersionMismatchError       = &Error{"version mismatch", nil}
-	DatabaseNotOpenError       = &Error{"db is not open", nil}
-	DatabaseAlreadyOpenedError = &Error{"db already open", nil}
-	TransactionInProgressError = &Error{"writable transaction is already in progress", nil}
-	InvalidTransactionError    = &Error{"txn is invalid", nil}
-	BucketAlreadyExistsError   = &Error{"bucket already exists", nil}
+	// InvalidError is returned when a data file is not a Bolt-formatted database.
+	InvalidError = &Error{"Invalid database", nil}
+
+	// VersionMismatchError is returned when the data file was created with a 
+	// different version of Bolt.
+	VersionMismatchError = &Error{"version mismatch", nil}
+
+	// DatabaseNotOpenError is returned when a DB instance is accessed before it
+	// is opened or after it is closed.
+	DatabaseNotOpenError = &Error{"database not open", nil}
+
+	// DatabaseOpenError is returned when opening a database that is
+	// already open.
+	DatabaseOpenError = &Error{"database already open", nil}
+
+	// BucketNotFoundError is returned when trying to access a bucket that has
+	// not been created yet.
+	BucketNotFoundError = &Error{"bucket not found", nil}
+
+	// BucketExistsError is returned when creating a bucket that already exists.
+	BucketExistsError = &Error{"bucket already exists", nil}
+
+	// BucketNameRequiredError is returned when creating a bucket with a blank name.
+	BucketNameRequiredError = &Error{"bucket name required", nil}
+
+	// BucketNameTooLargeError is returned when creating a bucket with a name
+	// that is longer than MaxBucketNameSize.
+	BucketNameTooLargeError = &Error{"bucket name too large", nil}
+
+	// KeyRequiredError is returned when inserting a zero-length key.
+	KeyRequiredError = &Error{"key required", nil}
+
+	// KeyTooLargeError is returned when inserting a key that is larger than MaxKeySize.
+	KeyTooLargeError = &Error{"key too large", nil}
+
+	// ValueTooLargeError is returned when inserting a value that is larger than MaxValueSize.
+	ValueTooLargeError = &Error{"value too large", nil}
 )
 
+// Error represents an error condition caused by Bolt.
 type Error struct {
 	message string
 	cause   error
 }
 
+// Error returns a string representation of the error.
 func (e *Error) Error() string {
 	if e.cause != nil {
 		return e.message + ": " + e.cause.Error()