wip - change AndExpr to contain arbitrary many predicates

Signed-off-by: Andres Taylor <[email protected]>

go/vt/sqlparser/analyzer_test.go

@@ -209,10 +209,10 @@ func TestAndExpressions(t *testing.T) {
 				equalExpr,
 				equalExpr,
 			},
-			expectedOutput: &AndExpr{
-				Left:  greaterThanExpr,
-				Right: equalExpr,
-			},
+			expectedOutput: &AndExpr{Predicates: Exprs{
+				greaterThanExpr,
+				equalExpr,
+			}},
 		},
 		{
 			name: "two equal inputs",

go/vt/sqlparser/ast.go

@@ -2263,9 +2263,7 @@ type (
 	}
 
 	// AndExpr represents an AND expression.
-	AndExpr struct {
-		Left, Right Expr
-	}
+	AndExpr struct{ Predicates []Expr }
 
 	// OrExpr represents an OR expression.
 	OrExpr struct {

go/vt/sqlparser/ast_format.go

@@ -1297,7 +1297,13 @@ func (node Exprs) Format(buf *TrackedBuffer) {
 
 // Format formats the node.
 func (node *AndExpr) Format(buf *TrackedBuffer) {
-	buf.astPrintf(node, "%l and %r", node.Left, node.Right)
+	for idx, expr := range node.Predicates {
+		if idx == len(node.Predicates)-1 {
+			buf.astPrintf(node, "%r", expr)
+			continue
+		}
+		buf.astPrintf(node, "%l and ", expr)
+	}
 }
 
 // Format formats the node.

go/vt/sqlparser/ast_funcs.go

@@ -66,6 +66,27 @@ func Append(buf *strings.Builder, node SQLNode) {
 	node.FormatFast(tbuf)
 }
 
+func createAndExpr(exprL, exprR Expr) *AndExpr {
+	leftAnd, isLeftAnd := exprL.(*AndExpr)
+	rightAnd, isRightAnd := exprR.(*AndExpr)
+	if isLeftAnd && isRightAnd {
+		return &AndExpr{
+			Predicates: append(leftAnd.Predicates, rightAnd.Predicates...),
+		}
+	}
+	if isLeftAnd {
+		leftAnd.Predicates = append(leftAnd.Predicates, exprR)
+		return leftAnd
+	}
+	if isRightAnd {
+		rightAnd.Predicates = append([]Expr{exprL}, rightAnd.Predicates...)
+		return rightAnd
+	}
+	return &AndExpr{
+		Predicates: Exprs{exprL, exprR},
+	}
+}
+
 // IndexColumn describes a column or expression in an index definition with optional length (for column)
 type IndexColumn struct {
 	// Only one of Column or Expression can be specified
@@ -1239,10 +1260,8 @@ func addPredicate(where *Where, pred Expr) *Where {
 			Expr: pred,
 		}
 	}
-	where.Expr = &AndExpr{
-		Left:  where.Expr,
-		Right: pred,
-	}
+
+	where.Expr = createAndExpr(where.Expr, pred)
 	return where
 }
 
@@ -2336,8 +2355,7 @@ func SplitAndExpression(filters []Expr, node Expr) []Expr {
 	}
 	switch node := node.(type) {
 	case *AndExpr:
-		filters = SplitAndExpression(filters, node.Left)
-		return SplitAndExpression(filters, node.Right)
+		return append(filters, node.Predicates...)
 	}
 	return append(filters, node)
 }
@@ -2350,26 +2368,30 @@ func AndExpressions(exprs ...Expr) Expr {
 	case 1:
 		return exprs[0]
 	default:
-		result := (Expr)(nil)
-	outer:
+		var unique Exprs
 		// we'll loop and remove any duplicates
-		for i, expr := range exprs {
-			if expr == nil {
-				continue
-			}
-			if result == nil {
-				result = expr
-				continue outer
+		uniqueAdd := func(e Expr) {
+			for _, existing := range unique {
+				if Equals.Expr(e, existing) {
+					return
+				}
 			}
+			unique = append(unique, e)
+		}
 
-			for j := 0; j < i; j++ {
-				if Equals.Expr(expr, exprs[j]) {
-					continue outer
+		for _, expr := range exprs {
+			switch expr := expr.(type) {
+			case *AndExpr:
+				for _, p := range expr.Predicates {
+					uniqueAdd(p)
 				}
+			case nil:
+				continue
+			default:
+				uniqueAdd(expr)
 			}
-			result = &AndExpr{Left: result, Right: expr}
 		}
-		return result
+		return &AndExpr{Predicates: unique}
 	}
 }
 

go/vt/sqlparser/precedence_test.go

@@ -18,18 +18,24 @@ package sqlparser
 
 import (
 	"fmt"
+	"strings"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/require"
+
+	"vitess.io/vitess/go/slice"
 )
 
 func readable(node Expr) string {
 	switch node := node.(type) {
 	case *OrExpr:
 		return fmt.Sprintf("(%s or %s)", readable(node.Left), readable(node.Right))
 	case *AndExpr:
-		return fmt.Sprintf("(%s and %s)", readable(node.Left), readable(node.Right))
+		predicates := slice.Map(node.Predicates, func(from Expr) string {
+			return readable(from)
+		})
+		return fmt.Sprintf("(%s)", strings.Join(predicates, " and "))
 	case *XorExpr:
 		return fmt.Sprintf("(%s xor %s)", readable(node.Left), readable(node.Right))
 	case *BinaryExpr:
@@ -153,7 +159,7 @@ func TestParens(t *testing.T) {
 		{in: "((((((1000))))))", expected: "1000"},
 		{in: "100 - (50 + 10)", expected: "100 - (50 + 10)"},
 		{in: "100 - 50 + 10", expected: "100 - 50 + 10"},
-		{in: "true and (true and true)", expected: "true and (true and true)"},
+		{in: "true and (true and true)", expected: "true and true and true"},
 		{in: "10 - 2 - 1", expected: "10 - 2 - 1"},
 		{in: "(10 - 2) - 1", expected: "10 - 2 - 1"},
 		{in: "10 - (2 - 1)", expected: "10 - (2 - 1)"},
@@ -193,6 +199,6 @@ func TestRandom(t *testing.T) {
 
 		// Then the unparsing should be the same as the input query
 		outputOfParseResult := String(parsedInput)
-		require.Equal(t, outputOfParseResult, inputQ)
+		require.Equal(t, inputQ, outputOfParseResult)
 	}
 }