/
param_marker.go
62 lines (54 loc) · 1.64 KB
/
param_marker.go
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//
//
// 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package expressions
import (
"github.com/Dong-Chan/alloydb/context"
"github.com/Dong-Chan/alloydb/expression"
)
var _ expression.Expression = (*ParamMarker)(nil)
// ParamMarker expresion holds a place for another expression.
// Used in parsing prepare statement.
type ParamMarker struct {
// Expr is the expression to be evaluated in this place holder.
Expr expression.Expression
}
// Clone implements the Expression Clone interface.
func (pm *ParamMarker) Clone() (expression.Expression, error) {
np := &ParamMarker{}
if pm.Expr != nil {
var err error
np.Expr, err = pm.Expr.Clone()
if err != nil {
return nil, err
}
}
return np, nil
}
// Eval implements the Expression Eval interface.
func (pm *ParamMarker) Eval(ctx context.Context, args map[interface{}]interface{}) (v interface{}, err error) {
if pm.Expr != nil {
return pm.Expr.Eval(ctx, args)
}
return nil, nil
}
// IsStatic implements the Expression IsStatic interface, always returns false.
func (pm *ParamMarker) IsStatic() bool {
return false
}
// String implements the Expression String interface.
func (pm *ParamMarker) String() string {
if pm.Expr != nil {
return pm.Expr.String()
}
return "?"
}