1 files changed, 17 insertions, 0 deletions
diff --git a/pkg/query/errors.go b/pkg/query/errors.go
index 0a9664f..35f8c19 100644
--- a/pkg/query/errors.go
+++ b/pkg/query/errors.go
@@ -8,12 +8,25 @@ import (
 var ErrQueryFormat = errors.New("Incorrect query format")
 var ErrDatetimeTokenParse = errors.New("Unrecognized format for datetime token")
 
+// output errors
+var ErrUnrecognizedOutputToken = errors.New("Unrecognized output token")
+var ErrExpectedMoreStringTokens = errors.New("Expected more string tokens")
+
+// optimizer errors
+var ErrUnexpectedValueType = errors.New("Unexpected value type")
+var ErrEmptyResult = errors.New("Queries are contradictory, will lead to an empty result")
+
+
 type TokenError struct {
 	got      Token
 	gotPrev  Token
 	wantPrev string
 }
 
+type CompileError struct {
+	s string
+}
+
 func (e *TokenError) Error() string {
 	if e.wantPrev != "" {
 		return fmt.Sprintf("Unexpected token: got %s, got previous %s want previous %s", e.got, e.gotPrev, e.wantPrev)
@@ -21,3 +34,7 @@ func (e *TokenError) Error() string {
 
 	return fmt.Sprintf("Unexpected token: got %s, got previous %s", e.got, e.gotPrev)
 }
+
+func (e *CompileError) Error() string {
+	return fmt.Sprintf("Compile error: %s", e.s)
+}