route/vendor/github.com/zclconf/go-cty/cty/convert/conversion_collection.go

187 lines
4.8 KiB
Go

package convert
import (
"github.com/zclconf/go-cty/cty"
)
// conversionCollectionToList returns a conversion that will apply the given
// conversion to all of the elements of a collection (something that supports
// ForEachElement and LengthInt) and then returns the result as a list.
//
// "conv" can be nil if the elements are expected to already be of the
// correct type and just need to be re-wrapped into a list. (For example,
// if we're converting from a set into a list of the same element type.)
func conversionCollectionToList(ety cty.Type, conv conversion) conversion {
return func(val cty.Value, path cty.Path) (cty.Value, error) {
elems := make([]cty.Value, 0, val.LengthInt())
i := int64(0)
path = append(path, nil)
it := val.ElementIterator()
for it.Next() {
_, val := it.Element()
var err error
path[len(path)-1] = cty.IndexStep{
Key: cty.NumberIntVal(i),
}
if conv != nil {
val, err = conv(val, path)
if err != nil {
return cty.NilVal, err
}
}
elems = append(elems, val)
i++
}
if len(elems) == 0 {
return cty.ListValEmpty(ety), nil
}
return cty.ListVal(elems), nil
}
}
// conversionTupleToList returns a conversion that will take a value of the
// given tuple type and return a list of the given element type.
//
// Will panic if the given tupleType isn't actually a tuple type.
func conversionTupleToList(tupleType cty.Type, listEty cty.Type, unsafe bool) conversion {
tupleEtys := tupleType.TupleElementTypes()
if len(tupleEtys) == 0 {
// Empty tuple short-circuit
return func(val cty.Value, path cty.Path) (cty.Value, error) {
return cty.ListValEmpty(listEty), nil
}
}
if listEty == cty.DynamicPseudoType {
// This is a special case where the caller wants us to find
// a suitable single type that all elements can convert to, if
// possible.
listEty, _ = unify(tupleEtys, unsafe)
if listEty == cty.NilType {
return nil
}
}
elemConvs := make([]conversion, len(tupleEtys))
for i, tupleEty := range tupleEtys {
if tupleEty.Equals(listEty) {
// no conversion required
continue
}
elemConvs[i] = getConversion(tupleEty, listEty, unsafe)
if elemConvs[i] == nil {
// If any of our element conversions are impossible, then the our
// whole conversion is impossible.
return nil
}
}
// If we fall out here then a conversion is possible, using the
// element conversions in elemConvs
return func(val cty.Value, path cty.Path) (cty.Value, error) {
elems := make([]cty.Value, 0, len(elemConvs))
path = append(path, nil)
i := int64(0)
it := val.ElementIterator()
for it.Next() {
_, val := it.Element()
var err error
path[len(path)-1] = cty.IndexStep{
Key: cty.NumberIntVal(i),
}
conv := elemConvs[i]
if conv != nil {
val, err = conv(val, path)
if err != nil {
return cty.NilVal, err
}
}
elems = append(elems, val)
i++
}
return cty.ListVal(elems), nil
}
}
// conversionObjectToMap returns a conversion that will take a value of the
// given object type and return a map of the given element type.
//
// Will panic if the given objectType isn't actually an object type.
func conversionObjectToMap(objectType cty.Type, mapEty cty.Type, unsafe bool) conversion {
objectAtys := objectType.AttributeTypes()
if len(objectAtys) == 0 {
// Empty object short-circuit
return func(val cty.Value, path cty.Path) (cty.Value, error) {
return cty.MapValEmpty(mapEty), nil
}
}
if mapEty == cty.DynamicPseudoType {
// This is a special case where the caller wants us to find
// a suitable single type that all elements can convert to, if
// possible.
objectAtysList := make([]cty.Type, 0, len(objectAtys))
for _, aty := range objectAtys {
objectAtysList = append(objectAtysList, aty)
}
mapEty, _ = unify(objectAtysList, unsafe)
if mapEty == cty.NilType {
return nil
}
}
elemConvs := make(map[string]conversion, len(objectAtys))
for name, objectAty := range objectAtys {
if objectAty.Equals(mapEty) {
// no conversion required
continue
}
elemConvs[name] = getConversion(objectAty, mapEty, unsafe)
if elemConvs[name] == nil {
// If any of our element conversions are impossible, then the our
// whole conversion is impossible.
return nil
}
}
// If we fall out here then a conversion is possible, using the
// element conversions in elemConvs
return func(val cty.Value, path cty.Path) (cty.Value, error) {
elems := make(map[string]cty.Value, len(elemConvs))
path = append(path, nil)
it := val.ElementIterator()
for it.Next() {
name, val := it.Element()
var err error
path[len(path)-1] = cty.IndexStep{
Key: name,
}
conv := elemConvs[name.AsString()]
if conv != nil {
val, err = conv(val, path)
if err != nil {
return cty.NilVal, err
}
}
elems[name.AsString()] = val
}
return cty.MapVal(elems), nil
}
}