Upgrade hcl to v2

Signed-off-by: Patrick Van Stee <patrick@vanstee.me>

vendor/github.com/zclconf/go-cty/cty/convert/public.go

@@ -0,0 +1,83 @@
+package convert
+
+import (
+	"errors"
+
+	"github.com/zclconf/go-cty/cty"
+)
+
+// This file contains the public interface of this package, which is intended
+// to be a small, convenient interface designed for easy integration into
+// a hypothetical language type checker and interpreter.
+
+// Conversion is a named function type representing a conversion from a
+// value of one type to a value of another type.
+//
+// The source type for a conversion is always the source type given to
+// the function that returned the Conversion, but there is no way to recover
+// that from a Conversion value itself. If a Conversion is given a value
+// that is not of its expected type (with the exception of DynamicPseudoType,
+// which is always supported) then the function may panic or produce undefined
+// results.
+type Conversion func(in cty.Value) (out cty.Value, err error)
+
+// GetConversion returns a Conversion between the given in and out Types if
+// a safe one is available, or returns nil otherwise.
+func GetConversion(in cty.Type, out cty.Type) Conversion {
+	return retConversion(getConversion(in, out, false))
+}
+
+// GetConversionUnsafe returns a Conversion between the given in and out Types
+// if either a safe or unsafe one is available, or returns nil otherwise.
+func GetConversionUnsafe(in cty.Type, out cty.Type) Conversion {
+	return retConversion(getConversion(in, out, true))
+}
+
+// Convert returns the result of converting the given value to the given type
+// if an safe or unsafe conversion is available, or returns an error if such a
+// conversion is impossible.
+//
+// This is a convenience wrapper around calling GetConversionUnsafe and then
+// immediately passing the given value to the resulting function.
+func Convert(in cty.Value, want cty.Type) (cty.Value, error) {
+	if in.Type().Equals(want) {
+		return in, nil
+	}
+
+	conv := GetConversionUnsafe(in.Type(), want)
+	if conv == nil {
+		return cty.NilVal, errors.New(MismatchMessage(in.Type(), want))
+	}
+	return conv(in)
+}
+
+// Unify attempts to find the most general type that can be converted from
+// all of the given types. If this is possible, that type is returned along
+// with a slice of necessary conversions for some of the given types.
+//
+// If no common supertype can be found, this function returns cty.NilType and
+// a nil slice.
+//
+// If a common supertype *can* be found, the returned slice will always be
+// non-nil and will contain a non-nil conversion for each given type that
+// needs to be converted, with indices corresponding to the input slice.
+// Any given type that does *not* need conversion (because it is already of
+// the appropriate type) will have a nil Conversion.
+//
+// cty.DynamicPseudoType is, as usual, a special case. If the given type list
+// contains a mixture of dynamic and non-dynamic types, the dynamic types are
+// disregarded for type selection and a conversion is returned for them that
+// will attempt a late conversion of the given value to the target type,
+// failing with a conversion error if the eventual concrete type is not
+// compatible. If *all* given types are DynamicPseudoType, or in the
+// degenerate case of an empty slice of types, the returned type is itself
+// cty.DynamicPseudoType and no conversions are attempted.
+func Unify(types []cty.Type) (cty.Type, []Conversion) {
+	return unify(types, false)
+}
+
+// UnifyUnsafe is the same as Unify except that it may return unsafe
+// conversions in situations where a safe conversion isn't also available.
+func UnifyUnsafe(types []cty.Type) (cty.Type, []Conversion) {
+	return unify(types, true)
+}