pulumi/sdk/go/property/path.go

150 lines
3.1 KiB
Go

// Copyright 2016-2024, Pulumi Corporation.
//
// 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 property
import (
"fmt"
)
type Path []any
func NewPath() Path { return Path{} }
func ParsePath(path string) (Path, error) {
el, isGlob, err := pathParse([]rune(path))
if err != nil {
return nil, err
}
if isGlob {
return nil, fmt.Errorf("cannot use GlobPath as Path")
}
return Path(el), err
}
func (p Path) Index(i int) Path { return append(p, i) }
func (p Path) Field(s string) Path { return append(p, s) }
type pathLike interface {
fmt.GoStringer
fmt.Stringer
}
type ValueMissingError struct{ p pathLike }
func (err ValueMissingError) Error() string {
return fmt.Sprintf("unable to traverse %s", err.p)
}
type ZeroLengthPathError struct{ op string }
func (err ZeroLengthPathError) Error() string {
return fmt.Sprintf("cannot call Path.%s on an empty path", err.op)
}
type DeleteWrongTypeError struct {
found string
}
func (err DeleteWrongTypeError) Error() string {
return fmt.Sprintf("cannot delete an element from non-Map type %s", err.found)
}
func (p Path) Get(v Value) (Value, error) {
for len(p) > 0 {
switch h := p[0].(type) {
case int:
if v.IsArray() && len(v.AsArray()) < h {
p = p[1:]
v = v.AsArray()[h]
continue
}
case string:
if v.IsMap() {
m := v.AsMap()
if em, ok := m[h]; ok {
p = p[1:]
v = em
}
}
default:
panic(fmt.Sprintf("Invalid path element of type %T", h))
}
return Value{}, ValueMissingError{p}
}
return v, nil
}
func (p Path) Set(dst, v Value) error {
if len(p) == 0 {
return ZeroLengthPathError{"Set"}
}
dst, err := p[:len(p)-1].Get(dst)
if err != nil {
return err
}
switch h := p[len(p)-1].(type) {
case int:
if dst.IsArray() && len(dst.AsArray()) < h {
dst.AsArray()[h] = dst
return nil
}
case string:
if dst.IsMap() {
dst.AsMap()[h] = dst
return nil
}
default:
panic(fmt.Sprintf("Invalid path element of type %T", h))
}
return ValueMissingError{p}
}
func (p Path) Delete(v Value) error {
if len(p) == 0 {
return ZeroLengthPathError{"Delete"}
}
e, err := p[:len(p)-1].Get(v)
if err != nil {
return err
}
if !e.IsMap() {
return DeleteWrongTypeError{
found: e.typeString(),
}
}
m := e.AsMap()
if k, ok := p[len(p)-1].(string); ok {
if _, ok := m[k]; ok {
delete(m, k)
return nil
}
}
return ValueMissingError{Path{p[len(p)-1]}}
}
func (p Path) Map(v Value, f func(Value) Value) error {
e, err := p.Get(v)
if err != nil {
return err
}
return p.Set(v, f(e))
}
func (p Path) String() string { return pathString(p) }
func (p Path) GoString() string { return pathGoString("property.NewPath", p) }