Upgrade hcl to v2

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

vendor/github.com/zclconf/go-cty/cty/helper.go

@@ -0,0 +1,99 @@
+package cty
+
+import (
+	"fmt"
+)
+
+// anyUnknown is a helper to easily check if a set of values contains any
+// unknowns, for operations that short-circuit to return unknown in that case.
+func anyUnknown(values ...Value) bool {
+	for _, val := range values {
+		if val.v == unknown {
+			return true
+		}
+	}
+	return false
+}
+
+// typeCheck tests whether all of the given values belong to the given type.
+// If the given types are a mixture of the given type and the dynamic
+// pseudo-type then a short-circuit dynamic value is returned. If the given
+// values are all of the correct type but at least one is unknown then
+// a short-circuit unknown value is returned. If any other types appear then
+// an error is returned. Otherwise (finally!) the result is nil, nil.
+func typeCheck(required Type, ret Type, values ...Value) (shortCircuit *Value, err error) {
+	hasDynamic := false
+	hasUnknown := false
+
+	for i, val := range values {
+		if val.ty == DynamicPseudoType {
+			hasDynamic = true
+			continue
+		}
+
+		if !val.Type().Equals(required) {
+			return nil, fmt.Errorf(
+				"type mismatch: want %s but value %d is %s",
+				required.FriendlyName(),
+				i, val.ty.FriendlyName(),
+			)
+		}
+
+		if val.v == unknown {
+			hasUnknown = true
+		}
+	}
+
+	if hasDynamic {
+		return &DynamicVal, nil
+	}
+
+	if hasUnknown {
+		ret := UnknownVal(ret)
+		return &ret, nil
+	}
+
+	return nil, nil
+}
+
+// mustTypeCheck is a wrapper around typeCheck that immediately panics if
+// any error is returned.
+func mustTypeCheck(required Type, ret Type, values ...Value) *Value {
+	shortCircuit, err := typeCheck(required, ret, values...)
+	if err != nil {
+		panic(err)
+	}
+	return shortCircuit
+}
+
+// shortCircuitForceType takes the return value from mustTypeCheck and
+// replaces it with an unknown of the given type if the original value was
+// DynamicVal.
+//
+// This is useful for operations that are specified to always return a
+// particular type, since then a dynamic result can safely be "upgrade" to
+// a strongly-typed unknown, which then allows subsequent operations to
+// be actually type-checked.
+//
+// It is safe to use this only if the operation in question is defined as
+// returning either a value of the given type or panicking, since we know
+// then that subsequent operations won't run if the operation panics.
+//
+// If the given short-circuit value is *not* DynamicVal then it must be
+// of the given type, or this function will panic.
+func forceShortCircuitType(shortCircuit *Value, ty Type) *Value {
+	if shortCircuit == nil {
+		return nil
+	}
+
+	if shortCircuit.ty == DynamicPseudoType {
+		ret := UnknownVal(ty)
+		return &ret
+	}
+
+	if !shortCircuit.ty.Equals(ty) {
+		panic("forceShortCircuitType got value of wrong type")
+	}
+
+	return shortCircuit
+}