Files
dolthub--doltgresql/server/analyzer/split.go
T
2026-07-13 12:32:25 +08:00

66 lines
2.1 KiB
Go

// 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 analyzer
import (
"github.com/dolthub/go-mysql-server/sql"
"github.com/dolthub/go-mysql-server/sql/expression"
pgexprs "github.com/dolthub/doltgresql/server/expression"
pgtypes "github.com/dolthub/doltgresql/server/types"
)
// splitConjunction breaks AND expressions into their left and right parts, recursively.
func splitConjunction(ctx *sql.Context, expr sql.Expression) []sql.Expression {
if expr == nil {
return nil
}
switch expr := expr.(type) {
case *expression.And:
return append(
splitConjunction(ctx, expr.LeftChild),
splitConjunction(ctx, expr.RightChild)...,
)
case *pgexprs.GMSCast:
// We should check to see if we need to preserve the cast on each child individually
split := splitConjunction(ctx, expr.Child())
for i := range split {
if _, ok := split[i].Type(ctx).(*pgtypes.DoltgresType); !ok {
split[i] = pgexprs.NewGMSCast(split[i])
}
}
return split
default:
return []sql.Expression{expr}
}
}
// LogicTreeWalker is a walker that removes GMSCast and other Doltgres specific expression nodes from
// logic expression trees. This allows the analyzer logic to correctly reason about expressions in filters
// to apply indexes.
type LogicTreeWalker struct{}
var _ sql.ExpressionTreeFilter = &LogicTreeWalker{}
// Next implements the sql.ExpressionTreeFilter interface.
func (l *LogicTreeWalker) Next(e sql.Expression) sql.Expression {
switch expr := e.(type) {
case *pgexprs.GMSCast:
return l.Next(expr.Child())
default:
return e
}
}