Add REVOKE and DENY statement parsing support (#48)

Author: kyleconroy

ast/deny_statement.go

@@ -0,0 +1,12 @@
+package ast
+
+// DenyStatement represents a DENY statement
+type DenyStatement struct {
+	Permissions          []*Permission
+	Principals           []*SecurityPrincipal
+	CascadeOption        bool
+	SecurityTargetObject *SecurityTargetObject
+}
+
+func (s *DenyStatement) node()      {}
+func (s *DenyStatement) statement() {}

ast/revoke_statement.go

@@ -0,0 +1,13 @@
+package ast
+
+// RevokeStatement represents a REVOKE statement
+type RevokeStatement struct {
+	Permissions          []*Permission
+	Principals           []*SecurityPrincipal
+	GrantOptionFor       bool
+	CascadeOption        bool
+	SecurityTargetObject *SecurityTargetObject
+}
+
+func (s *RevokeStatement) node()      {}
+func (s *RevokeStatement) statement() {}

parser/lexer.go

@@ -155,6 +155,7 @@ const (
 	// Security keywords
 	TokenGrant
 	TokenRevoke
+	TokenDeny
 	TokenTo
 	TokenPublic
 
@@ -816,6 +817,7 @@ var keywords = map[string]TokenType{
 	"MAXDOP":        TokenMaxdop,
 	"GRANT":         TokenGrant,
 	"REVOKE":        TokenRevoke,
+	"DENY":          TokenDeny,
 	"TO":            TokenTo,
 	"PUBLIC":        TokenPublic,
 	"COMMIT":        TokenCommit,