chore: import upstream snapshot with attribution

server/expression/not.go

@@ -0,0 +1,120 @@
+// Copyright 2024 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expression
+
+import (
+	"context"
+
+	"github.com/cockroachdb/errors"
+	"github.com/dolthub/go-mysql-server/sql"
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// Not represents a NOT expression.
+type Not struct {
+	child sql.Expression
+}
+
+var _ vitess.Injectable = (*Not)(nil)
+var _ sql.Expression = (*Not)(nil)
+
+// NewNot returns a new *Not.
+func NewNot() *Not {
+	return &Not{
+		child: nil,
+	}
+}
+
+var _ sql.IndexComparisonExpression = (*Not)(nil)
+
+// Children implements the sql.Expression interface.
+func (n *Not) Children() []sql.Expression {
+	return []sql.Expression{n.child}
+}
+
+// Eval implements the sql.Expression interface.
+func (n *Not) Eval(ctx *sql.Context, row sql.Row) (any, error) {
+	val, err := n.child.Eval(ctx, row)
+	if err != nil {
+		return nil, err
+	}
+	if val == nil {
+		return nil, nil
+	}
+	boolVal, ok := val.(bool)
+	if !ok {
+		return nil, errors.Errorf("NOT only applies to boolean values")
+	}
+	return !boolVal, nil
+}
+
+// IsNullable implements the sql.Expression interface.
+func (n *Not) IsNullable(ctx *sql.Context) bool {
+	return true
+}
+
+// Resolved implements the sql.Expression interface.
+func (n *Not) Resolved() bool {
+	return n.child != nil && n.child.Resolved()
+}
+
+// String implements the sql.Expression interface.
+func (n *Not) String() string {
+	if n.child == nil {
+		return "NOT ?"
+	}
+	return "NOT " + n.child.String()
+}
+
+// Type implements the sql.Expression interface.
+func (n *Not) Type(ctx *sql.Context) sql.Type {
+	return pgtypes.Bool
+}
+
+// WithChildren implements the sql.Expression interface.
+func (n *Not) WithChildren(ctx *sql.Context, children ...sql.Expression) (sql.Expression, error) {
+	if len(children) != 1 {
+		return nil, sql.ErrInvalidChildrenNumber.New(n, len(children), 1)
+	}
+	return &Not{
+		child: children[0],
+	}, nil
+}
+
+// WithResolvedChildren implements the vitess.InjectableExpression interface.
+func (n *Not) WithResolvedChildren(ctx context.Context, children []any) (any, error) {
+	if len(children) != 1 {
+		return nil, errors.Errorf("invalid vitess child count, expected `1` but got `%d`", len(children))
+	}
+	child, ok := children[0].(sql.Expression)
+	if !ok {
+		return nil, errors.Errorf("expected vitess child to be an expression but has type `%T`", children[0])
+	}
+	return &Not{
+		child: child,
+	}, nil
+}
+
+// IndexScanOperation implements the sql.IndexComparisonExpression interface.
+func (n *Not) IndexScanOperation() (sql.IndexScanOp, sql.Expression, sql.Expression, bool) {
+	it, ok := n.child.(*InTuple)
+	if !ok {
+		return 0, nil, nil, false
+	}
+
+	return sql.IndexScanOpNotInSet, it.Left(), it.Right(), true
+}