From bd281ff21b798b42aa8e4a56997e7d8b01781e15 Mon Sep 17 00:00:00 2001
From: Denis Arh <denis.arh@gmail.com>
Date: Fri, 18 Oct 2019 17:44:20 +0200
Subject: [PATCH] Improve ql to support <ident>.<ident> syntax

---
 pkg/ql/ast_parser.go      | 13 ++++++++++++-
 pkg/ql/ast_parser_test.go |  8 ++++++++
 pkg/ql/lexer.go           |  1 +
 pkg/ql/token_codes.go     |  1 +
 4 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/pkg/ql/ast_parser.go b/pkg/ql/ast_parser.go
index 4d177d457..5c1e8f244 100644
--- a/pkg/ql/ast_parser.go
+++ b/pkg/ql/ast_parser.go
@@ -217,7 +217,18 @@ func (p *Parser) parseIdent(t Token) (list ASTNode, err error) {
 		}
 	}
 
-	return p.OnIdent(Ident{Value: t.literal})
+	i := Ident{Value: t.literal}
+
+	if p.peekToken(1).Is(DOT) {
+		p.nextToken()
+		i.Value += "."
+		l2 := p.nextToken()
+		if l2.Is(IDENT) {
+			i.Value += l2.literal
+		}
+	}
+
+	return p.OnIdent(i)
 }
 
 func (p *Parser) parseSet() (list ASTSet, err error) {
diff --git a/pkg/ql/ast_parser_test.go b/pkg/ql/ast_parser_test.go
index 71007aaa7..2b2e0188f 100644
--- a/pkg/ql/ast_parser_test.go
+++ b/pkg/ql/ast_parser_test.go
@@ -269,6 +269,14 @@ func TestAstParser_ColumnParser(t *testing.T) {
 				},
 			},
 		},
+		{
+			in: `a.b`,
+			cols: Columns{
+				Column{
+					Expr: ASTNodes{Ident{Value: "a.b"}},
+				},
+			},
+		},
 		{
 			in: `DATE_FORMAT(some_date, '%Y-%m-01')`,
 			cols: Columns{
diff --git a/pkg/ql/lexer.go b/pkg/ql/lexer.go
index 10f757166..876afa828 100644
--- a/pkg/ql/lexer.go
+++ b/pkg/ql/lexer.go
@@ -44,6 +44,7 @@ func NewLexer(r io.Reader) *Lexer {
 			// @todo ensure operator order (eg != is valid, =! is not)
 			&TokenConsumerGeneric{token: OPERATOR, whitelist: CHAR_WHITELIST_OPERATORS},
 			&TokenConsumerGeneric{token: COMMA, whitelist: ",", maxLength: 1},
+			&TokenConsumerGeneric{token: DOT, whitelist: ".", maxLength: 1},
 			&TokenConsumerGeneric{token: PARENTHESIS_OPEN, whitelist: "(", maxLength: 1},
 			&TokenConsumerGeneric{token: PARENTHESIS_CLOSE, whitelist: ")", maxLength: 1},
 			&TokenConsumerString{},
diff --git a/pkg/ql/token_codes.go b/pkg/ql/token_codes.go
index 8ea28b1da..bd2fd9f64 100644
--- a/pkg/ql/token_codes.go
+++ b/pkg/ql/token_codes.go
@@ -19,6 +19,7 @@ const (
 	NUMBER // 4
 	STRING
 	COMMA    // ,
+	DOT      // .
 	OPERATOR // + - / *
 	PARENTHESIS_OPEN
 	PARENTHESIS_CLOSE