route/vendor/github.com/zclconf/go-cty/cty/gocty/in.go

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2017-12-02 23:34:35 +00:00
package gocty
import (
"math/big"
"reflect"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/set"
)
// ToCtyValue produces a cty.Value from a Go value. The result will conform
// to the given type, or an error will be returned if this is not possible.
//
// The target type serves as a hint to resolve ambiguities in the mapping.
// For example, the Go type set.Set tells us that the value is a set but
// does not describe the set's element type. This also allows for convenient
// conversions, such as populating a set from a slice rather than having to
// first explicitly instantiate a set.Set.
//
// The audience of this function is assumed to be the developers of Go code
// that is integrating with cty, and thus the error messages it returns are
// presented from Go's perspective. These messages are thus not appropriate
// for display to end-users. An error returned from ToCtyValue represents a
// bug in the calling program, not user error.
func ToCtyValue(val interface{}, ty cty.Type) (cty.Value, error) {
// 'path' starts off as empty but will grow for each level of recursive
// call we make, so by the time toCtyValue returns it is likely to have
// unused capacity on the end of it, depending on how deeply-recursive
// the given Type is.
path := make(cty.Path, 0)
return toCtyValue(reflect.ValueOf(val), ty, path)
}
func toCtyValue(val reflect.Value, ty cty.Type, path cty.Path) (cty.Value, error) {
switch ty {
case cty.Bool:
return toCtyBool(val, path)
case cty.Number:
return toCtyNumber(val, path)
case cty.String:
return toCtyString(val, path)
case cty.DynamicPseudoType:
return toCtyDynamic(val, path)
}
switch {
case ty.IsListType():
return toCtyList(val, ty.ElementType(), path)
case ty.IsMapType():
return toCtyMap(val, ty.ElementType(), path)
case ty.IsSetType():
return toCtySet(val, ty.ElementType(), path)
case ty.IsObjectType():
return toCtyObject(val, ty.AttributeTypes(), path)
case ty.IsTupleType():
return toCtyTuple(val, ty.TupleElementTypes(), path)
case ty.IsCapsuleType():
return toCtyCapsule(val, ty, path)
}
// We should never fall out here
return cty.NilVal, path.NewErrorf("unsupported target type %#v", ty)
}
func toCtyBool(val reflect.Value, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(cty.Bool), nil
}
switch val.Kind() {
case reflect.Bool:
return cty.BoolVal(val.Bool()), nil
default:
return cty.NilVal, path.NewErrorf("can't convert Go %s to bool", val.Kind())
}
}
func toCtyNumber(val reflect.Value, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(cty.Number), nil
}
switch val.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return cty.NumberIntVal(val.Int()), nil
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
return cty.NumberUIntVal(val.Uint()), nil
case reflect.Float32, reflect.Float64:
return cty.NumberFloatVal(val.Float()), nil
case reflect.Struct:
if val.Type().AssignableTo(bigIntType) {
bigInt := val.Interface().(big.Int)
bigFloat := (&big.Float{}).SetInt(&bigInt)
val = reflect.ValueOf(*bigFloat)
}
if val.Type().AssignableTo(bigFloatType) {
bigFloat := val.Interface().(big.Float)
return cty.NumberVal(&bigFloat), nil
}
fallthrough
default:
return cty.NilVal, path.NewErrorf("can't convert Go %s to number", val.Kind())
}
}
func toCtyString(val reflect.Value, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(cty.String), nil
}
switch val.Kind() {
case reflect.String:
return cty.StringVal(val.String()), nil
default:
return cty.NilVal, path.NewErrorf("can't convert Go %s to string", val.Kind())
}
}
func toCtyList(val reflect.Value, ety cty.Type, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(cty.List(ety)), nil
}
switch val.Kind() {
case reflect.Slice:
if val.IsNil() {
return cty.NullVal(cty.List(ety)), nil
}
fallthrough
case reflect.Array:
if val.Len() == 0 {
return cty.ListValEmpty(ety), nil
}
// While we work on our elements we'll temporarily grow
// path to give us a place to put our index step.
path = append(path, cty.PathStep(nil))
vals := make([]cty.Value, val.Len())
for i := range vals {
var err error
path[len(path)-1] = cty.IndexStep{
Key: cty.NumberIntVal(int64(i)),
}
vals[i], err = toCtyValue(val.Index(i), ety, path)
if err != nil {
return cty.NilVal, err
}
}
// Discard our extra path segment, retaining it as extra capacity
// for future appending to the path.
path = path[:len(path)-1]
return cty.ListVal(vals), nil
default:
return cty.NilVal, path.NewErrorf("can't convert Go %s to %#v", val.Kind(), cty.List(ety))
}
}
func toCtyMap(val reflect.Value, ety cty.Type, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(cty.Map(ety)), nil
}
switch val.Kind() {
case reflect.Map:
if val.IsNil() {
return cty.NullVal(cty.Map(ety)), nil
}
if val.Len() == 0 {
return cty.MapValEmpty(ety), nil
}
keyType := val.Type().Key()
if keyType.Kind() != reflect.String {
return cty.NilVal, path.NewErrorf("can't convert Go map with key type %s; key type must be string", keyType)
}
// While we work on our elements we'll temporarily grow
// path to give us a place to put our index step.
path = append(path, cty.PathStep(nil))
vals := make(map[string]cty.Value, val.Len())
for _, kv := range val.MapKeys() {
k := kv.String()
var err error
path[len(path)-1] = cty.IndexStep{
Key: cty.StringVal(k),
}
vals[k], err = toCtyValue(val.MapIndex(reflect.ValueOf(k)), ety, path)
if err != nil {
return cty.NilVal, err
}
}
// Discard our extra path segment, retaining it as extra capacity
// for future appending to the path.
path = path[:len(path)-1]
return cty.MapVal(vals), nil
default:
return cty.NilVal, path.NewErrorf("can't convert Go %s to %#v", val.Kind(), cty.Map(ety))
}
}
func toCtySet(val reflect.Value, ety cty.Type, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(cty.Set(ety)), nil
}
var vals []cty.Value
switch val.Kind() {
case reflect.Slice:
if val.IsNil() {
return cty.NullVal(cty.Set(ety)), nil
}
fallthrough
case reflect.Array:
if val.Len() == 0 {
return cty.SetValEmpty(ety), nil
}
vals = make([]cty.Value, val.Len())
for i := range vals {
var err error
vals[i], err = toCtyValue(val.Index(i), ety, path)
if err != nil {
return cty.NilVal, err
}
}
case reflect.Struct:
if !val.Type().AssignableTo(setType) {
return cty.NilVal, path.NewErrorf("can't convert Go %s to %#v", val.Type(), cty.Set(ety))
}
rawSet := val.Interface().(set.Set)
inVals := rawSet.Values()
if len(inVals) == 0 {
return cty.SetValEmpty(ety), nil
}
vals = make([]cty.Value, len(inVals))
for i := range inVals {
var err error
vals[i], err = toCtyValue(reflect.ValueOf(inVals[i]), ety, path)
if err != nil {
return cty.NilVal, err
}
}
default:
return cty.NilVal, path.NewErrorf("can't convert Go %s to %#v", val.Kind(), cty.Set(ety))
}
return cty.SetVal(vals), nil
}
func toCtyObject(val reflect.Value, attrTypes map[string]cty.Type, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(cty.Object(attrTypes)), nil
}
switch val.Kind() {
case reflect.Map:
if val.IsNil() {
return cty.NullVal(cty.Object(attrTypes)), nil
}
keyType := val.Type().Key()
if keyType.Kind() != reflect.String {
return cty.NilVal, path.NewErrorf("can't convert Go map with key type %s; key type must be string", keyType)
}
if len(attrTypes) == 0 {
return cty.EmptyObjectVal, nil
}
// While we work on our elements we'll temporarily grow
// path to give us a place to put our GetAttr step.
path = append(path, cty.PathStep(nil))
haveKeys := make(map[string]struct{}, val.Len())
for _, kv := range val.MapKeys() {
haveKeys[kv.String()] = struct{}{}
}
vals := make(map[string]cty.Value, len(attrTypes))
for k, at := range attrTypes {
var err error
path[len(path)-1] = cty.GetAttrStep{
Name: k,
}
if _, have := haveKeys[k]; !have {
vals[k] = cty.NullVal(at)
continue
}
vals[k], err = toCtyValue(val.MapIndex(reflect.ValueOf(k)), at, path)
if err != nil {
return cty.NilVal, err
}
}
// Discard our extra path segment, retaining it as extra capacity
// for future appending to the path.
path = path[:len(path)-1]
return cty.ObjectVal(vals), nil
case reflect.Struct:
if len(attrTypes) == 0 {
return cty.EmptyObjectVal, nil
}
// While we work on our elements we'll temporarily grow
// path to give us a place to put our GetAttr step.
path = append(path, cty.PathStep(nil))
attrFields := structTagIndices(val.Type())
vals := make(map[string]cty.Value, len(attrTypes))
for k, at := range attrTypes {
path[len(path)-1] = cty.GetAttrStep{
Name: k,
}
if fieldIdx, have := attrFields[k]; have {
var err error
vals[k], err = toCtyValue(val.Field(fieldIdx), at, path)
if err != nil {
return cty.NilVal, err
}
} else {
vals[k] = cty.NullVal(at)
}
}
// Discard our extra path segment, retaining it as extra capacity
// for future appending to the path.
path = path[:len(path)-1]
return cty.ObjectVal(vals), nil
default:
return cty.NilVal, path.NewErrorf("can't convert Go %s to %#v", val.Kind(), cty.Object(attrTypes))
}
}
func toCtyTuple(val reflect.Value, elemTypes []cty.Type, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(cty.Tuple(elemTypes)), nil
}
switch val.Kind() {
case reflect.Slice:
if val.IsNil() {
return cty.NullVal(cty.Tuple(elemTypes)), nil
}
if val.Len() != len(elemTypes) {
return cty.NilVal, path.NewErrorf("wrong number of elements %d; need %d", val.Len(), len(elemTypes))
}
if len(elemTypes) == 0 {
return cty.EmptyTupleVal, nil
}
// While we work on our elements we'll temporarily grow
// path to give us a place to put our Index step.
path = append(path, cty.PathStep(nil))
vals := make([]cty.Value, len(elemTypes))
for i, ety := range elemTypes {
var err error
path[len(path)-1] = cty.IndexStep{
Key: cty.NumberIntVal(int64(i)),
}
vals[i], err = toCtyValue(val.Index(i), ety, path)
if err != nil {
return cty.NilVal, err
}
}
// Discard our extra path segment, retaining it as extra capacity
// for future appending to the path.
path = path[:len(path)-1]
return cty.TupleVal(vals), nil
case reflect.Struct:
fieldCount := val.Type().NumField()
if fieldCount != len(elemTypes) {
return cty.NilVal, path.NewErrorf("wrong number of struct fields %d; need %d", fieldCount, len(elemTypes))
}
if len(elemTypes) == 0 {
return cty.EmptyTupleVal, nil
}
// While we work on our elements we'll temporarily grow
// path to give us a place to put our Index step.
path = append(path, cty.PathStep(nil))
vals := make([]cty.Value, len(elemTypes))
for i, ety := range elemTypes {
var err error
path[len(path)-1] = cty.IndexStep{
Key: cty.NumberIntVal(int64(i)),
}
vals[i], err = toCtyValue(val.Field(i), ety, path)
if err != nil {
return cty.NilVal, err
}
}
// Discard our extra path segment, retaining it as extra capacity
// for future appending to the path.
path = path[:len(path)-1]
return cty.TupleVal(vals), nil
default:
return cty.NilVal, path.NewErrorf("can't convert Go %s to %#v", val.Kind(), cty.Tuple(elemTypes))
}
}
func toCtyCapsule(val reflect.Value, capsuleType cty.Type, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(capsuleType), nil
}
if val.Kind() != reflect.Ptr {
if !val.CanAddr() {
return cty.NilVal, path.NewErrorf("source value for capsule %#v must be addressable", capsuleType)
}
val = val.Addr()
}
if !val.Type().Elem().AssignableTo(capsuleType.EncapsulatedType()) {
return cty.NilVal, path.NewErrorf("value of type %T not compatible with capsule %#v", val.Interface(), capsuleType)
}
return cty.CapsuleVal(capsuleType, val.Interface()), nil
}
func toCtyDynamic(val reflect.Value, path cty.Path) (cty.Value, error) {
if val = toCtyUnwrapPointer(val); !val.IsValid() {
return cty.NullVal(cty.DynamicPseudoType), nil
}
switch val.Kind() {
case reflect.Struct:
if !val.Type().AssignableTo(valueType) {
return cty.NilVal, path.NewErrorf("can't convert Go %s dynamically; only cty.Value allowed", val.Type())
}
return val.Interface().(cty.Value), nil
default:
return cty.NilVal, path.NewErrorf("can't convert Go %s dynamically; only cty.Value allowed", val.Kind())
}
}
// toCtyUnwrapPointer is a helper for dealing with Go pointers. It has three
// possible outcomes:
//
// - Given value isn't a pointer, so it's just returned as-is.
// - Given value is a non-nil pointer, in which case it is dereferenced
// and the result returned.
// - Given value is a nil pointer, in which case an invalid value is returned.
//
// For nested pointer types, like **int, they are all dereferenced in turn
// until a non-pointer value is found, or until a nil pointer is encountered.
func toCtyUnwrapPointer(val reflect.Value) reflect.Value {
for val.Kind() == reflect.Ptr || val.Kind() == reflect.Interface {
if val.IsNil() {
return reflect.Value{}
}
val = val.Elem()
}
return val
}