terraform/configs/configschema/empty_value.go

63 lines
1.9 KiB
Go

package configschema
import (
"github.com/zclconf/go-cty/cty"
)
// EmptyValue returns the "empty value" for the recieving block, which for
// a block type is a non-null object where all of the attribute values are
// the empty values of the block's attributes and nested block types.
//
// In other words, it returns the value that would be returned if an empty
// block were decoded against the recieving schema, assuming that no required
// attribute or block constraints were honored.
func (b *Block) EmptyValue() cty.Value {
vals := make(map[string]cty.Value)
for name, attrS := range b.Attributes {
vals[name] = attrS.EmptyValue()
}
for name, blockS := range b.BlockTypes {
vals[name] = blockS.EmptyValue()
}
return cty.ObjectVal(vals)
}
// EmptyValue returns the "empty value" for the receiving attribute, which is
// the value that would be returned if there were no definition of the attribute
// at all, ignoring any required constraint.
func (a *Attribute) EmptyValue() cty.Value {
if a.NestedType != nil {
return cty.NullVal(a.NestedType.ImpliedType())
}
return cty.NullVal(a.Type)
}
// EmptyValue returns the "empty value" for when there are zero nested blocks
// present of the receiving type.
func (b *NestedBlock) EmptyValue() cty.Value {
switch b.Nesting {
case NestingSingle:
return cty.NullVal(b.Block.ImpliedType())
case NestingGroup:
return b.Block.EmptyValue()
case NestingList:
if ty := b.Block.ImpliedType(); ty.HasDynamicTypes() {
return cty.EmptyTupleVal
} else {
return cty.ListValEmpty(ty)
}
case NestingMap:
if ty := b.Block.ImpliedType(); ty.HasDynamicTypes() {
return cty.EmptyObjectVal
} else {
return cty.MapValEmpty(ty)
}
case NestingSet:
return cty.SetValEmpty(b.Block.ImpliedType())
default:
// Should never get here because the above is intended to be exhaustive,
// but we'll be robust and return a result nonetheless.
return cty.NullVal(cty.DynamicPseudoType)
}
}