Support ql between/not between operator

For number type, IE (Field1 BETWEEN X X) or (Field1 NOT BETWEEN X X)

server/pkg/ql/ast_nodes.go

@@ -319,15 +319,30 @@ func (nn parserNodes) ToAST() (out *ASTNode) {
 		// Have the op consume what it needs.
 		arg := auxArgs[bestOpIx]
 		if !isUnary(arg.Ref) {
-			arg.Args = append(arg.Args, auxArgs[bestOpIx-1], auxArgs[bestOpIx+1])
+			for i, auxArg := range auxArgs {
+				if isOperator(auxArg.Ref) {
+					break
+				}
+
+				if i == bestOpIx {
+					continue
+				}
+
+				arg.Args = append(arg.Args, auxArg)
+			}
+
 			// this is not needed anymore so we can remove it
 			arg.pMeta = nil
 
 			// Remove the consumed bits and replace it with the new bit
 			aux := auxArgs[0 : bestOpIx-1]
 			aux = append(aux, arg)
-			// +1 for right side, +1 because the left index is inclusive
-			aux = append(aux, auxArgs[bestOpIx+2:]...)
+			// +X for right side, +1 because the left index is inclusive
+			skip := 2
+			if len(arg.Args) > 2 {
+				skip = len(arg.Args)
+			}
+			aux = append(aux, auxArgs[bestOpIx+skip:]...)
 			auxArgs = aux
 		} else {
 			arg.Args = append(arg.Args, auxArgs[bestOpIx+1])

server/pkg/ql/parser_nodes.go

@@ -95,6 +95,10 @@ var (
 		// str comp.
 		`LIKE`:     {name: `like`, weight: 40},
 		`NOT LIKE`: {name: `nlike`, weight: 40},
+
+		// range comp.
+		`BETWEEN`:     {name: `between`, weight: 40},
+		`NOT BETWEEN`: {name: `nbetween`, weight: 40},
 	}
 )
 
@@ -102,6 +106,10 @@ func isUnary(s string) bool {
 	return s == "!" || s == "not"
 }
 
+func isOperator(s string) bool {
+	return s == "and" || s == "or" || s == "xor"
+}
+
 func getOp(op string) *opDef {
 	o, ok := ops[strings.ToUpper(op)]
 	if !ok {

server/pkg/ql/token_consumers.go

@@ -89,7 +89,7 @@ func (TokenConsumerIdent) Consume(s RuneReader) Token {
 		return Token{code: LNULL}
 	case "TRUE", "FALSE":
 		return Token{code: LBOOL, literal: lit}
-	case "IS", "LIKE", "NOT", "AND", "OR", "XOR", "IN":
+	case "IS", "LIKE", "NOT", "AND", "OR", "XOR", "IN", "BETWEEN":
 		return Token{code: OPERATOR, literal: lit}
 	case "DESC", "ASC", "INTERVAL":
 		return Token{code: KEYWORD, literal: lit}

server/store/adapters/rdbms/ql/ref.go

@@ -13,8 +13,9 @@ type (
 	ExprHandlerMap map[string]*ExprHandler
 
 	ExprHandler struct {
-		Handler  func(...exp.Expression) exp.Expression
-		HandlerE func(...exp.Expression) (exp.Expression, error)
+		Handler      func(...exp.Expression) exp.Expression
+		HandlerE     func(...exp.Expression) (exp.Expression, error)
+		RangeHandler func(exp.Expression, exp.RangeVal) exp.Expression
 	}
 )
 
@@ -181,6 +182,18 @@ var (
 			},
 		},
 
+		// range operation
+		"between": {
+			Handler: func(args ...exp.Expression) exp.Expression {
+				return exp.NewRangeExpression(exp.BetweenOp, args[0], exp.NewRangeVal(args[1], args[2]))
+			},
+		},
+		"nbetween": {
+			Handler: func(args ...exp.Expression) exp.Expression {
+				return exp.NewRangeExpression(exp.NotBetweenOp, args[0], exp.NewRangeVal(args[1], args[2]))
+			},
+		},
+
 		"is": {
 			Handler: func(args ...exp.Expression) exp.Expression {
 				return exp.NewBooleanExpression(exp.IsOp, args[0], args[1])