terraform: clean up EvalNodes

terraform/eval.go

@@ -7,18 +7,10 @@ import (
 // EvalNode is the interface that must be implemented by graph nodes to
 // evaluate/execute.
 type EvalNode interface {
-	// Args returns the arguments for this node as well as the list of
-	// expected types. The expected types are only used for type checking
-	// and not used at runtime.
-	Args() ([]EvalNode, []EvalType)
-
 	// Eval evaluates this node with the given context. The second parameter
 	// are the argument values. These will match in order and 1-1 with the
 	// results of the Args() return value.
-	Eval(EvalContext, []interface{}) (interface{}, error)
+	Eval(EvalContext) (interface{}, error)
-
-	// Type returns the type that will be returned by this node.
-	Type() EvalType
 }
 
 // GraphNodeEvalable is the interface that graph nodes must implement
@@ -51,19 +43,8 @@ func Eval(n EvalNode, ctx EvalContext) (interface{}, error) {
 // EvalRaw is like Eval except that it returns all errors, even if they
 // signal something normal such as EvalEarlyExitError.
 func EvalRaw(n EvalNode, ctx EvalContext) (interface{}, error) {
-	argNodes, _ := n.Args()
-	args := make([]interface{}, len(argNodes))
-	for i, n := range argNodes {
-		v, err := EvalRaw(n, ctx)
-		if err != nil {
-			return nil, err
-		}
-
-		args[i] = v
-	}
-
 	log.Printf("[DEBUG] eval: %T", n)
-	output, err := n.Eval(ctx, args)
+	output, err := n.Eval(ctx)
 	if err != nil {
 		log.Printf("[ERROR] eval: %T, err: %s", n, err)
 	}

terraform/eval_apply.go

@@ -21,13 +21,8 @@ type EvalApply struct {
 	Error     *error
 }
 
-func (n *EvalApply) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalApply) Eval(
+func (n *EvalApply) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	diff := *n.Diff
 	provider := *n.Provider
 	state := *n.State
@@ -108,10 +103,6 @@ func (n *EvalApply) Eval(
 	return nil, nil
 }
 
-func (n *EvalApply) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalApplyPost is an EvalNode implementation that does the post-Apply work
 type EvalApplyPost struct {
 	Info  *InstanceInfo
@@ -119,13 +110,8 @@ type EvalApplyPost struct {
 	Error *error
 }
 
-func (n *EvalApplyPost) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalApplyPost) Eval(
+func (n *EvalApplyPost) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	state := *n.State
 
 	{
@@ -141,10 +127,6 @@ func (n *EvalApplyPost) Eval(
 	return nil, *n.Error
 }
 
-func (n *EvalApplyPost) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalApplyProvisioners is an EvalNode implementation that executes
 // the provisioners for a resource.
 //
@@ -160,13 +142,8 @@ type EvalApplyProvisioners struct {
 	Error          *error
 }
 
-func (n *EvalApplyProvisioners) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalApplyProvisioners) Eval(
+func (n *EvalApplyProvisioners) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	state := *n.State
 
 	if !*n.CreateNew {
@@ -226,10 +203,6 @@ func (n *EvalApplyProvisioners) Eval(
 	return nil, nil
 }
 
-func (n *EvalApplyProvisioners) Type() EvalType {
-	return EvalTypeNull
-}
-
 func (n *EvalApplyProvisioners) apply(ctx EvalContext) error {
 	state := *n.State
 

terraform/eval_count.go

@@ -11,13 +11,8 @@ type EvalCountFixZeroOneBoundary struct {
 	Resource *config.Resource
 }
 
-func (n *EvalCountFixZeroOneBoundary) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalCountFixZeroOneBoundary) Eval(
+func (n *EvalCountFixZeroOneBoundary) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	// Get the count, important for knowing whether we're supposed to
 	// be adding the zero, or trimming it.
 	count, err := n.Resource.Count()
@@ -53,7 +48,3 @@ func (n *EvalCountFixZeroOneBoundary) Eval(
 
 	return nil, nil
 }
-
-func (n *EvalCountFixZeroOneBoundary) Type() EvalType {
-	return EvalTypeNull
-}

terraform/eval_diff.go

@@ -12,13 +12,8 @@ type EvalCompareDiff struct {
 	One, Two **InstanceDiff
 }
 
-func (n *EvalCompareDiff) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalCompareDiff) Eval(
+func (n *EvalCompareDiff) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	one, two := *n.One, *n.Two
 
 	// If either are nil, let them be empty
@@ -55,37 +50,22 @@ func (n *EvalCompareDiff) Eval(
 	return nil, nil
 }
 
-func (n *EvalCompareDiff) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalDiff is an EvalNode implementation that does a refresh for
 // a resource.
 type EvalDiff struct {
 	Info        *InstanceInfo
-	Config      EvalNode
+	Config      **ResourceConfig
-	Provider    EvalNode
+	Provider    *ResourceProvider
-	State       EvalNode
+	State       **InstanceState
 	Output      **InstanceDiff
 	OutputState **InstanceState
 }
 
-func (n *EvalDiff) Args() ([]EvalNode, []EvalType) {
-	return []EvalNode{n.Config, n.Provider, n.State},
-		[]EvalType{EvalTypeConfig, EvalTypeResourceProvider,
-			EvalTypeInstanceState}
-}
-
 // TODO: test
-func (n *EvalDiff) Eval(
+func (n *EvalDiff) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
+	state := *n.State
-	// Extract our arguments
+	config := *n.Config
-	var state *InstanceState
+	provider := *n.Provider
-	config := args[0].(*ResourceConfig)
-	provider := args[1].(ResourceProvider)
-	if args[2] != nil {
-		state = args[2].(*InstanceState)
-	}
 
 	// Call pre-diff hook
 	err := ctx.Hook(func(h Hook) (HookAction, error) {
@@ -154,33 +134,20 @@ func (n *EvalDiff) Eval(
 		}
 	}
 
-	return state, nil
+	return nil, nil
-}
-
-func (n *EvalDiff) Type() EvalType {
-	return EvalTypeInstanceState
 }
 
 // EvalDiffDestroy is an EvalNode implementation that returns a plain
 // destroy diff.
 type EvalDiffDestroy struct {
 	Info   *InstanceInfo
-	State  EvalNode
+	State  **InstanceState
 	Output **InstanceDiff
 }
 
-func (n *EvalDiffDestroy) Args() ([]EvalNode, []EvalType) {
-	return []EvalNode{n.State}, []EvalType{EvalTypeInstanceState}
-}
-
 // TODO: test
-func (n *EvalDiffDestroy) Eval(
+func (n *EvalDiffDestroy) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
+	state := *n.State
-	// Extract our arguments
-	var state *InstanceState
-	if args[0] != nil {
-		state = args[0].(*InstanceState)
-	}
 
 	// If there is no state or we don't have an ID, we're already destroyed
 	if state == nil || state.ID == "" {
@@ -212,23 +179,14 @@ func (n *EvalDiffDestroy) Eval(
 	return nil, nil
 }
 
-func (n *EvalDiffDestroy) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalDiffDestroyModule is an EvalNode implementation that writes the diff to
 // the full diff.
 type EvalDiffDestroyModule struct {
 	Path []string
 }
 
-func (n *EvalDiffDestroyModule) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalDiffDestroyModule) Eval(
+func (n *EvalDiffDestroyModule) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	diff, lock := ctx.Diff()
 
 	// Acquire the lock so that we can do this safely concurrently
@@ -245,10 +203,6 @@ func (n *EvalDiffDestroyModule) Eval(
 	return nil, nil
 }
 
-func (n *EvalDiffDestroyModule) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalDiffTainted is an EvalNode implementation that writes the diff to
 // the full diff.
 type EvalDiffTainted struct {
@@ -256,13 +210,8 @@ type EvalDiffTainted struct {
 	Diff **InstanceDiff
 }
 
-func (n *EvalDiffTainted) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalDiffTainted) Eval(
+func (n *EvalDiffTainted) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	state, lock := ctx.State()
 
 	// Get a read lock so we can access this instance
@@ -289,10 +238,6 @@ func (n *EvalDiffTainted) Eval(
 	return nil, nil
 }
 
-func (n *EvalDiffTainted) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalReadDiff is an EvalNode implementation that writes the diff to
 // the full diff.
 type EvalReadDiff struct {
@@ -300,13 +245,7 @@ type EvalReadDiff struct {
 	Diff **InstanceDiff
 }
 
-func (n *EvalReadDiff) Args() ([]EvalNode, []EvalType) {
+func (n *EvalReadDiff) Eval(ctx EvalContext) (interface{}, error) {
-	return nil, nil
-}
-
-// TODO: test
-func (n *EvalReadDiff) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	diff, lock := ctx.Diff()
 
 	// Acquire the lock so that we can do this safely concurrently
@@ -324,10 +263,6 @@ func (n *EvalReadDiff) Eval(
 	return nil, nil
 }
 
-func (n *EvalReadDiff) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalWriteDiff is an EvalNode implementation that writes the diff to
 // the full diff.
 type EvalWriteDiff struct {
@@ -335,13 +270,8 @@ type EvalWriteDiff struct {
 	Diff **InstanceDiff
 }
 
-func (n *EvalWriteDiff) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalWriteDiff) Eval(
+func (n *EvalWriteDiff) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	diff, lock := ctx.Diff()
 
 	// The diff to write, if its empty it should write nil
@@ -367,7 +297,3 @@ func (n *EvalWriteDiff) Eval(
 
 	return nil, nil
 }
-
-func (n *EvalWriteDiff) Type() EvalType {
-	return EvalTypeNull
-}

terraform/eval_filter_operation.go

@@ -32,18 +32,9 @@ type EvalOpFilter struct {
 	Node EvalNode
 }
 
-func (n *EvalOpFilter) Args() ([]EvalNode, []EvalType) {
-	return []EvalNode{n.Node}, []EvalType{n.Node.Type()}
-}
-
 // TODO: test
-func (n *EvalOpFilter) Eval(
+func (n *EvalOpFilter) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
+	return EvalRaw(n.Node, ctx)
-	return args[0], nil
-}
-
-func (n *EvalOpFilter) Type() EvalType {
-	return n.Node.Type()
 }
 
 // EvalNodeOpFilterable impl.

terraform/eval_if.go

@@ -6,13 +6,8 @@ type EvalIf struct {
 	Node EvalNode
 }
 
-func (n *EvalIf) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalIf) Eval(
+func (n *EvalIf) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	yes, err := n.If(ctx)
 	if err != nil {
 		return nil, err
@@ -24,7 +19,3 @@ func (n *EvalIf) Eval(
 
 	return nil, nil
 }
-
-func (n *EvalIf) Type() EvalType {
-	return EvalTypeNull
-}

terraform/eval_interpolate.go

@@ -9,17 +9,18 @@ import (
 type EvalInterpolate struct {
 	Config   *config.RawConfig
 	Resource *Resource
+	Output   **ResourceConfig
+}
+
+func (n *EvalInterpolate) Eval(ctx EvalContext) (interface{}, error) {
+	rc, err := ctx.Interpolate(n.Config, n.Resource)
+	if err != nil {
+		return nil, err
+	}
+
+	if n.Output != nil {
+		*n.Output = rc
 	}
 
-func (n *EvalInterpolate) Args() ([]EvalNode, []EvalType) {
 	return nil, nil
 }
-
-func (n *EvalInterpolate) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
-	return ctx.Interpolate(n.Config, n.Resource)
-}
-
-func (n *EvalInterpolate) Type() EvalType {
-	return EvalTypeConfig
-}

terraform/eval_interpolate_test.go

@@ -17,12 +17,14 @@ func TestEvalInterpolate(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 
-	n := &EvalInterpolate{Config: config}
+	var actual *ResourceConfig
+	n := &EvalInterpolate{Config: config, Output: &actual}
 	result := testResourceConfig(t, map[string]interface{}{})
 	ctx := &MockEvalContext{InterpolateConfigResult: result}
-	if actual, err := n.Eval(ctx, nil); err != nil {
+	if _, err := n.Eval(ctx); err != nil {
 		t.Fatalf("err: %s", err)
-	} else if actual != result {
+	}
+	if actual != result {
 		t.Fatalf("bad: %#v", actual)
 	}
 

terraform/eval_literal.go

@@ -1,20 +0,0 @@
-package terraform
-
-// EvalLiteral is an EvalNode implementation that returns a literal
-// value. This is very useful for testing as well as in practice.
-type EvalLiteral struct {
-	Value     interface{}
-	ValueType EvalType
-}
-
-func (n *EvalLiteral) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
-func (n *EvalLiteral) Eval(EvalContext, []interface{}) (interface{}, error) {
-	return n.Value, nil
-}
-
-func (n *EvalLiteral) Type() EvalType {
-	return n.ValueType
-}

terraform/eval_literal_test.go

@@ -1,27 +0,0 @@
-package terraform
-
-import (
-	"testing"
-)
-
-func TestEvalLiteral_impl(t *testing.T) {
-	var _ EvalNode = new(EvalLiteral)
-}
-
-func TestEvalLiteralEval(t *testing.T) {
-	n := &EvalLiteral{Value: 42}
-	actual, err := n.Eval(nil, nil)
-	if err != nil {
-		t.Fatalf("err: %s", err)
-	}
-	if actual != 42 {
-		t.Fatalf("bad: %#v", actual)
-	}
-}
-
-func TestEvalLiteralType(t *testing.T) {
-	n := &EvalLiteral{Value: 42, ValueType: EvalTypeConfig}
-	if actual := n.Type(); actual != EvalTypeConfig {
-		t.Fatalf("bad: %#v", actual)
-	}
-}

terraform/eval_noop.go

@@ -3,8 +3,6 @@ package terraform
 // EvalNoop is an EvalNode that does nothing.
 type EvalNoop struct{}
 
-func (EvalNoop) Args() ([]EvalNode, []EvalType) { return nil, nil }
+func (EvalNoop) Eval(EvalContext) (interface{}, error) {
-func (EvalNoop) Eval(EvalContext, []interface{}) (interface{}, error) {
 	return nil, nil
 }
-func (EvalNoop) Type() EvalType { return EvalTypeNull }

terraform/eval_output.go

@@ -13,13 +13,8 @@ type EvalWriteOutput struct {
 	Value *config.RawConfig
 }
 
-func (n *EvalWriteOutput) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalWriteOutput) Eval(
+func (n *EvalWriteOutput) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	cfg, err := ctx.Interpolate(n.Value, nil)
 	if err != nil {
 		// Ignore it
@@ -66,7 +61,3 @@ func (n *EvalWriteOutput) Eval(
 
 	return nil, nil
 }
-
-func (n *EvalWriteOutput) Type() EvalType {
-	return EvalTypeNull
-}

terraform/eval_provider.go

@@ -10,16 +10,11 @@ import (
 // a provider that is already initialized and retrieved.
 type EvalConfigProvider struct {
 	Provider string
-	Config   EvalNode
+	Config   **ResourceConfig
 }
 
-func (n *EvalConfigProvider) Args() ([]EvalNode, []EvalType) {
+func (n *EvalConfigProvider) Eval(ctx EvalContext) (interface{}, error) {
-	return []EvalNode{n.Config}, []EvalType{EvalTypeConfig}
+	cfg := *n.Config
-}
-
-func (n *EvalConfigProvider) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
-	cfg := args[0].(*ResourceConfig)
 
 	// If we have a configuration set, then use that
 	if input := ctx.ProviderInput(n.Provider); input != nil {
@@ -41,10 +36,6 @@ func (n *EvalConfigProvider) Eval(
 	return nil, ctx.ConfigureProvider(n.Provider, cfg)
 }
 
-func (n *EvalConfigProvider) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalInitProvider is an EvalNode implementation that initializes a provider
 // and returns nothing. The provider can be retrieved again with the
 // EvalGetProvider node.
@@ -52,19 +43,10 @@ type EvalInitProvider struct {
 	Name string
 }
 
-func (n *EvalInitProvider) Args() ([]EvalNode, []EvalType) {
+func (n *EvalInitProvider) Eval(ctx EvalContext) (interface{}, error) {
-	return nil, nil
-}
-
-func (n *EvalInitProvider) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	return ctx.InitProvider(n.Name)
 }
 
-func (n *EvalInitProvider) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalGetProvider is an EvalNode implementation that retrieves an already
 // initialized provider instance for the given name.
 type EvalGetProvider struct {
@@ -72,12 +54,7 @@ type EvalGetProvider struct {
 	Output *ResourceProvider
 }
 
-func (n *EvalGetProvider) Args() ([]EvalNode, []EvalType) {
+func (n *EvalGetProvider) Eval(ctx EvalContext) (interface{}, error) {
-	return nil, nil
-}
-
-func (n *EvalGetProvider) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	result := ctx.Provider(n.Name)
 	if result == nil {
 		return nil, fmt.Errorf("provider %s not initialized", n.Name)
@@ -87,11 +64,7 @@ func (n *EvalGetProvider) Eval(
 		*n.Output = result
 	}
 
-	return result, nil
+	return nil, nil
-}
-
-func (n *EvalGetProvider) Type() EvalType {
-	return EvalTypeResourceProvider
 }
 
 // EvalInputProvider is an EvalNode implementation that asks for input
@@ -102,12 +75,7 @@ type EvalInputProvider struct {
 	Config   *config.RawConfig
 }
 
-func (n *EvalInputProvider) Args() ([]EvalNode, []EvalType) {
+func (n *EvalInputProvider) Eval(ctx EvalContext) (interface{}, error) {
-	return nil, nil
-}
-
-func (n *EvalInputProvider) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	// If we already configured this provider, then don't do this again
 	if v := ctx.ProviderInput(n.Name); v != nil {
 		return nil, nil
@@ -138,7 +106,3 @@ func (n *EvalInputProvider) Eval(
 
 	return nil, nil
 }
-
-func (n *EvalInputProvider) Type() EvalType {
-	return EvalTypeNull
-}

terraform/eval_provider_test.go

@@ -12,14 +12,11 @@ func TestEvalConfigProvider_impl(t *testing.T) {
 func TestEvalConfigProvider(t *testing.T) {
 	config := testResourceConfig(t, map[string]interface{}{})
 	provider := &MockResourceProvider{}
-	n := &EvalConfigProvider{}
+	n := &EvalConfigProvider{Config: &config}
 
 	ctx := &MockEvalContext{ProviderProvider: provider}
-	args := []interface{}{config}
+	if _, err := n.Eval(ctx); err != nil {
-	if actual, err := n.Eval(ctx, args); err != nil {
 		t.Fatalf("err: %s", err)
-	} else if actual != nil {
-		t.Fatalf("bad: %#v", actual)
 	}
 
 	if !ctx.ConfigureProviderCalled {
@@ -30,22 +27,6 @@ func TestEvalConfigProvider(t *testing.T) {
 	}
 }
 
-func TestEvalConfigProvider_args(t *testing.T) {
-	config := testResourceConfig(t, map[string]interface{}{})
-	configNode := &EvalLiteral{Value: config}
-	n := &EvalConfigProvider{Provider: "foo", Config: configNode}
-
-	args, types := n.Args()
-	expectedArgs := []EvalNode{configNode}
-	expectedTypes := []EvalType{EvalTypeConfig}
-	if !reflect.DeepEqual(args, expectedArgs) {
-		t.Fatalf("bad: %#v", args)
-	}
-	if !reflect.DeepEqual(types, expectedTypes) {
-		t.Fatalf("bad: %#v", args)
-	}
-}
-
 func TestEvalInitProvider_impl(t *testing.T) {
 	var _ EvalNode = new(EvalInitProvider)
 }
@@ -54,10 +35,8 @@ func TestEvalInitProvider(t *testing.T) {
 	n := &EvalInitProvider{Name: "foo"}
 	provider := &MockResourceProvider{}
 	ctx := &MockEvalContext{InitProviderProvider: provider}
-	if actual, err := n.Eval(ctx, nil); err != nil {
+	if _, err := n.Eval(ctx); err != nil {
 		t.Fatalf("err: %s", err)
-	} else if actual != provider {
-		t.Fatalf("bad: %#v", actual)
 	}
 
 	if !ctx.InitProviderCalled {
@@ -73,12 +52,14 @@ func TestEvalGetProvider_impl(t *testing.T) {
 }
 
 func TestEvalGetProvider(t *testing.T) {
-	n := &EvalGetProvider{Name: "foo"}
+	var actual ResourceProvider
+	n := &EvalGetProvider{Name: "foo", Output: &actual}
 	provider := &MockResourceProvider{}
 	ctx := &MockEvalContext{ProviderProvider: provider}
-	if actual, err := n.Eval(ctx, nil); err != nil {
+	if _, err := n.Eval(ctx); err != nil {
 		t.Fatalf("err: %s", err)
-	} else if actual != provider {
+	}
+	if actual != provider {
 		t.Fatalf("bad: %#v", actual)
 	}
 

terraform/eval_provisioner.go

@@ -11,39 +11,26 @@ type EvalInitProvisioner struct {
 	Name string
 }
 
-func (n *EvalInitProvisioner) Args() ([]EvalNode, []EvalType) {
+func (n *EvalInitProvisioner) Eval(ctx EvalContext) (interface{}, error) {
-	return nil, nil
-}
-
-func (n *EvalInitProvisioner) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	return ctx.InitProvisioner(n.Name)
 }
 
-func (n *EvalInitProvisioner) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalGetProvisioner is an EvalNode implementation that retrieves an already
 // initialized provisioner instance for the given name.
 type EvalGetProvisioner struct {
 	Name   string
+	Output *ResourceProvisioner
 }
 
-func (n *EvalGetProvisioner) Args() ([]EvalNode, []EvalType) {
+func (n *EvalGetProvisioner) Eval(ctx EvalContext) (interface{}, error) {
-	return nil, nil
-}
-
-func (n *EvalGetProvisioner) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	result := ctx.Provisioner(n.Name)
 	if result == nil {
 		return nil, fmt.Errorf("provisioner %s not initialized", n.Name)
 	}
 
-	return result, nil
+	if n.Output != nil {
+		*n.Output = result
 	}
 
-func (n *EvalGetProvisioner) Type() EvalType {
+	return result, nil
-	return EvalTypeResourceProvisioner
 }

terraform/eval_provisioner_test.go

@@ -12,10 +12,8 @@ func TestEvalInitProvisioner(t *testing.T) {
 	n := &EvalInitProvisioner{Name: "foo"}
 	provisioner := &MockResourceProvisioner{}
 	ctx := &MockEvalContext{InitProvisionerProvisioner: provisioner}
-	if actual, err := n.Eval(ctx, nil); err != nil {
+	if _, err := n.Eval(ctx); err != nil {
 		t.Fatalf("err: %s", err)
-	} else if actual != provisioner {
-		t.Fatalf("bad: %#v", actual)
 	}
 
 	if !ctx.InitProvisionerCalled {
@@ -31,12 +29,14 @@ func TestEvalGetProvisioner_impl(t *testing.T) {
 }
 
 func TestEvalGetProvisioner(t *testing.T) {
-	n := &EvalGetProvisioner{Name: "foo"}
+	var actual ResourceProvisioner
+	n := &EvalGetProvisioner{Name: "foo", Output: &actual}
 	provisioner := &MockResourceProvisioner{}
 	ctx := &MockEvalContext{ProvisionerProvisioner: provisioner}
-	if actual, err := n.Eval(ctx, nil); err != nil {
+	if _, err := n.Eval(ctx); err != nil {
 		t.Fatalf("err: %s", err)
-	} else if actual != provisioner {
+	}
+	if actual != provisioner {
 		t.Fatalf("bad: %#v", actual)
 	}
 

terraform/eval_refresh.go

@@ -7,20 +7,15 @@ import (
 // EvalRefresh is an EvalNode implementation that does a refresh for
 // a resource.
 type EvalRefresh struct {
-	Provider EvalNode
+	Provider *ResourceProvider
 	State    **InstanceState
 	Info     *InstanceInfo
 	Output   **InstanceState
 }
 
-func (n *EvalRefresh) Args() ([]EvalNode, []EvalType) {
-	return []EvalNode{n.Provider}, []EvalType{EvalTypeResourceProvider}
-}
-
 // TODO: test
-func (n *EvalRefresh) Eval(
+func (n *EvalRefresh) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
+	provider := *n.Provider
-	provider := args[0].(ResourceProvider)
 	state := *n.State
 
 	// If we have no state, we don't do any refreshing
@@ -54,9 +49,6 @@ func (n *EvalRefresh) Eval(
 	if n.Output != nil {
 		*n.Output = state
 	}
-	return state, nil
-}
 
-func (n *EvalRefresh) Type() EvalType {
+	return nil, nil
-	return EvalTypeInstanceState
 }

terraform/eval_resource.go

@@ -6,17 +6,8 @@ type EvalInstanceInfo struct {
 	Info *InstanceInfo
 }
 
-func (n *EvalInstanceInfo) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalInstanceInfo) Eval(
+func (n *EvalInstanceInfo) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	n.Info.ModulePath = ctx.Path()
 	return nil, nil
 }
-
-func (n *EvalInstanceInfo) Type() EvalType {
-	return EvalTypeNull
-}

terraform/eval_sequence.go

@@ -5,33 +5,16 @@ type EvalSequence struct {
 	Nodes []EvalNode
 }
 
-func (n *EvalSequence) Args() ([]EvalNode, []EvalType) {
+func (n *EvalSequence) Eval(ctx EvalContext) (interface{}, error) {
-	types := make([]EvalType, len(n.Nodes))
+	for _, n := range n.Nodes {
-	for i, n := range n.Nodes {
+		if _, err := EvalRaw(n, ctx); err != nil {
-		types[i] = n.Type()
+			return nil, err
+		}
 	}
 
-	return n.Nodes, types
-}
-
-func (n *EvalSequence) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
-	// TODO: test
-	if len(args) == 0 {
 	return nil, nil
 }
 
-	return args[len(args)-1], nil
-}
-
-func (n *EvalSequence) Type() EvalType {
-	if len(n.Nodes) == 0 {
-		return EvalTypeNull
-	}
-
-	return n.Nodes[len(n.Nodes)-1].Type()
-}
-
 // EvalNodeFilterable impl.
 func (n *EvalSequence) Filter(fn EvalNodeFilterFunc) {
 	for i, node := range n.Nodes {

terraform/eval_state.go

@@ -13,13 +13,8 @@ type EvalReadState struct {
 	Output       **InstanceState
 }
 
-func (n *EvalReadState) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalReadState) Eval(
+func (n *EvalReadState) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	state, lock := ctx.State()
 
 	// Get a read lock so we can access this instance
@@ -63,10 +58,6 @@ func (n *EvalReadState) Eval(
 	return result, nil
 }
 
-func (n *EvalReadState) Type() EvalType {
-	return EvalTypeInstanceState
-}
-
 // EvalWriteState is an EvalNode implementation that reads the
 // InstanceState for a specific resource out of the state.
 type EvalWriteState struct {
@@ -79,13 +70,8 @@ type EvalWriteState struct {
 	TaintedClearPrimary bool
 }
 
-func (n *EvalWriteState) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalWriteState) Eval(
+func (n *EvalWriteState) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	state, lock := ctx.State()
 	if state == nil {
 		return nil, fmt.Errorf("cannot write state to nil state")
@@ -130,10 +116,6 @@ func (n *EvalWriteState) Eval(
 	return nil, nil
 }
 
-func (n *EvalWriteState) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalDeposeState is an EvalNode implementation that takes the primary
 // out of a state and makes it tainted. This is done at the beggining of
 // create-before-destroy calls so that the create can create while preserving
@@ -142,13 +124,8 @@ type EvalDeposeState struct {
 	Name string
 }
 
-func (n *EvalDeposeState) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalDeposeState) Eval(
+func (n *EvalDeposeState) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	state, lock := ctx.State()
 
 	// Get a read lock so we can access this instance
@@ -179,23 +156,14 @@ func (n *EvalDeposeState) Eval(
 	return nil, nil
 }
 
-func (n *EvalDeposeState) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalUndeposeState is an EvalNode implementation that reads the
 // InstanceState for a specific resource out of the state.
 type EvalUndeposeState struct {
 	Name string
 }
 
-func (n *EvalUndeposeState) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalUndeposeState) Eval(
+func (n *EvalUndeposeState) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	state, lock := ctx.State()
 
 	// Get a read lock so we can access this instance
@@ -226,7 +194,3 @@ func (n *EvalUndeposeState) Eval(
 
 	return nil, nil
 }
-
-func (n *EvalUndeposeState) Type() EvalType {
-	return EvalTypeNull
-}

terraform/eval_test.go

@@ -9,15 +9,13 @@ func TestMockEvalContext_impl(t *testing.T) {
 }
 
 func TestEval(t *testing.T) {
+	var result int
 	n := &testEvalAdd{
-		Items: []EvalNode{
+		Items:  []int{10, 32},
-			&EvalLiteral{Value: 10},
+		Result: &result,
-			&EvalLiteral{Value: 32},
-		},
 	}
 
-	result, err := Eval(n, nil)
+	if _, err := Eval(n, nil); err != nil {
-	if err != nil {
 		t.Fatalf("err: %s", err)
 	}
 
@@ -27,28 +25,16 @@ func TestEval(t *testing.T) {
 }
 
 type testEvalAdd struct {
-	Items []EvalNode
+	Items  []int
+	Result *int
 }
 
-func (n *testEvalAdd) Args() ([]EvalNode, []EvalType) {
+func (n *testEvalAdd) Eval(ctx EvalContext) (interface{}, error) {
-	types := make([]EvalType, len(n.Items))
-	for i, _ := range n.Items {
-		types[i] = EvalTypeInvalid
-	}
-
-	return n.Items, types
-}
-
-func (n *testEvalAdd) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	result := 0
-	for _, arg := range args {
+	for _, item := range n.Items {
-		result += arg.(int)
+		result += item
 	}
 
-	return result, nil
+	*n.Result = result
-}
+	return nil, nil
-
-func (n *testEvalAdd) Type() EvalType {
-	return EvalTypeInvalid
 }

terraform/eval_validate.go

@@ -23,13 +23,8 @@ type EvalValidateCount struct {
 	Resource *config.Resource
 }
 
-func (n *EvalValidateCount) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalValidateCount) Eval(
+func (n *EvalValidateCount) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	var count int
 	var errs []error
 	var err error
@@ -59,27 +54,17 @@ RETURN:
 	}
 }
 
-func (n *EvalValidateCount) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalValidateProvider is an EvalNode implementation that validates
 // the configuration of a resource.
 type EvalValidateProvider struct {
 	ProviderName string
-	Provider     EvalNode
+	Provider     *ResourceProvider
-	Config       EvalNode
+	Config       **ResourceConfig
 }
 
-func (n *EvalValidateProvider) Args() ([]EvalNode, []EvalType) {
+func (n *EvalValidateProvider) Eval(ctx EvalContext) (interface{}, error) {
-	return []EvalNode{n.Provider, n.Config},
+	provider := *n.Provider
-		[]EvalType{EvalTypeResourceProvider, EvalTypeConfig}
+	config := *n.Config
-}
-
-func (n *EvalValidateProvider) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
-	provider := args[0].(ResourceProvider)
-	config := args[1].(*ResourceConfig)
 
 	// Get the parent configuration if there is one
 	if parent := ctx.ParentProviderConfig(n.ProviderName); parent != nil {
@@ -98,27 +83,17 @@ func (n *EvalValidateProvider) Eval(
 	}
 }
 
-func (n *EvalValidateProvider) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalValidateProvisioner is an EvalNode implementation that validates
 // the configuration of a resource.
 type EvalValidateProvisioner struct {
-	Provisioner EvalNode
+	Provisioner *ResourceProvisioner
-	Config      EvalNode
+	Config      **ResourceConfig
 }
 
-func (n *EvalValidateProvisioner) Args() ([]EvalNode, []EvalType) {
+func (n *EvalValidateProvisioner) Eval(ctx EvalContext) (interface{}, error) {
-	return []EvalNode{n.Provisioner, n.Config},
+	provisioner := *n.Provisioner
-		[]EvalType{EvalTypeResourceProvisioner, EvalTypeConfig}
+	config := *n.Config
-}
+	warns, errs := provisioner.Validate(config)
-
-func (n *EvalValidateProvisioner) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
-	provider := args[0].(ResourceProvisioner)
-	config := args[1].(*ResourceConfig)
-	warns, errs := provider.Validate(config)
 	if len(warns) == 0 && len(errs) == 0 {
 		return nil, nil
 	}
@@ -129,30 +104,20 @@ func (n *EvalValidateProvisioner) Eval(
 	}
 }
 
-func (n *EvalValidateProvisioner) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalValidateResource is an EvalNode implementation that validates
 // the configuration of a resource.
 type EvalValidateResource struct {
-	Provider     EvalNode
+	Provider     *ResourceProvider
-	Config       EvalNode
+	Config       **ResourceConfig
 	ResourceName string
 	ResourceType string
 }
 
-func (n *EvalValidateResource) Args() ([]EvalNode, []EvalType) {
+func (n *EvalValidateResource) Eval(ctx EvalContext) (interface{}, error) {
-	return []EvalNode{n.Provider, n.Config},
-		[]EvalType{EvalTypeResourceProvider, EvalTypeConfig}
-}
-
-func (n *EvalValidateResource) Eval(
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	// TODO: test
 
-	provider := args[0].(ResourceProvider)
+	provider := *n.Provider
-	cfg := args[1].(*ResourceConfig)
+	cfg := *n.Config
 	warns, errs := provider.ValidateResource(n.ResourceType, cfg)
 
 	// If the resouce name doesn't match the name regular
@@ -174,7 +139,3 @@ func (n *EvalValidateResource) Eval(
 		Errors:   errs,
 	}
 }
-
-func (n *EvalValidateResource) Type() EvalType {
-	return EvalTypeNull
-}

terraform/eval_variable.go

@@ -10,43 +10,29 @@ type EvalSetVariables struct {
 	Variables map[string]string
 }
 
-func (n *EvalSetVariables) Args() ([]EvalNode, []EvalType) {
-	return nil, nil
-}
-
 // TODO: test
-func (n *EvalSetVariables) Eval(
+func (n *EvalSetVariables) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	ctx.SetVariables(n.Variables)
 	return nil, nil
 }
 
-func (n *EvalSetVariables) Type() EvalType {
-	return EvalTypeNull
-}
-
 // EvalVariableBlock is an EvalNode implementation that evaluates the
 // given configuration, and uses the final values as a way to set the
 // mapping.
 type EvalVariableBlock struct {
-	Config    EvalNode
+	Config    **ResourceConfig
 	Variables map[string]string
 }
 
-func (n *EvalVariableBlock) Args() ([]EvalNode, []EvalType) {
-	return []EvalNode{n.Config}, []EvalType{EvalTypeConfig}
-}
-
 // TODO: test
-func (n *EvalVariableBlock) Eval(
+func (n *EvalVariableBlock) Eval(ctx EvalContext) (interface{}, error) {
-	ctx EvalContext, args []interface{}) (interface{}, error) {
 	// Clear out the existing mapping
 	for k, _ := range n.Variables {
 		delete(n.Variables, k)
 	}
 
 	// Get our configuration
-	rc := args[0].(*ResourceConfig)
+	rc := *n.Config
 	for k, v := range rc.Config {
 		n.Variables[k] = v.(string)
 	}
@@ -58,7 +44,3 @@ func (n *EvalVariableBlock) Eval(
 
 	return nil, nil
 }
-
-func (n *EvalVariableBlock) Type() EvalType {
-	return EvalTypeNull
-}

terraform/evaltree_provider.go

@@ -7,11 +7,13 @@ import (
 // ProviderEvalTree returns the evaluation tree for initializing and
 // configuring providers.
 func ProviderEvalTree(n string, config *config.RawConfig) EvalNode {
+	var provider ResourceProvider
+	var resourceConfig *ResourceConfig
+
 	seq := make([]EvalNode, 0, 5)
 	seq = append(seq, &EvalInitProvider{Name: n})
 
 	// Input stuff
-	var provider ResourceProvider
 	seq = append(seq, &EvalOpFilter{
 		Ops: []walkOperation{walkInput},
 		Node: &EvalSequence{
@@ -34,14 +36,22 @@ func ProviderEvalTree(n string, config *config.RawConfig) EvalNode {
 		Ops: []walkOperation{walkValidate, walkRefresh, walkPlan, walkApply},
 		Node: &EvalSequence{
 			Nodes: []EvalNode{
+				&EvalGetProvider{
+					Name:   n,
+					Output: &provider,
+				},
+				&EvalInterpolate{
+					Config: config,
+					Output: &resourceConfig,
+				},
 				&EvalValidateProvider{
 					ProviderName: n,
-					Provider:     &EvalGetProvider{Name: n},
+					Provider:     &provider,
-					Config:       &EvalInterpolate{Config: config},
+					Config:       &resourceConfig,
 				},
 				&EvalConfigProvider{
 					Provider: n,
-					Config:   &EvalInterpolate{Config: config},
+					Config:   &resourceConfig,
 				},
 			},
 		},

terraform/graph_config_node.go

@@ -359,10 +359,16 @@ func (n *graphNodeModuleExpanded) Name() string {
 
 // GraphNodeEvalable impl.
 func (n *graphNodeModuleExpanded) EvalTree() EvalNode {
+	var resourceConfig *ResourceConfig
 	return &EvalSequence{
 		Nodes: []EvalNode{
+			&EvalInterpolate{
+				Config: n.InputConfig,
+				Output: &resourceConfig,
+			},
+
 			&EvalVariableBlock{
-				Config:    &EvalInterpolate{Config: n.InputConfig},
+				Config:    &resourceConfig,
 				Variables: n.Variables,
 			},
 

terraform/transform_orphan.go

@@ -171,6 +171,7 @@ func (n *graphNodeOrphanResource) ProvidedBy() []string {
 
 // GraphNodeEvalable impl.
 func (n *graphNodeOrphanResource) EvalTree() EvalNode {
+	var provider ResourceProvider
 	var state *InstanceState
 
 	seq := &EvalSequence{Nodes: make([]EvalNode, 0, 5)}
@@ -184,13 +185,17 @@ func (n *graphNodeOrphanResource) EvalTree() EvalNode {
 		Ops: []walkOperation{walkRefresh},
 		Node: &EvalSequence{
 			Nodes: []EvalNode{
+				&EvalGetProvider{
+					Name:   n.ProvidedBy()[0],
+					Output: &provider,
+				},
 				&EvalReadState{
 					Name:   n.ResourceName,
 					Output: &state,
 				},
 				&EvalRefresh{
 					Info:     info,
-					Provider: &EvalGetProvider{Name: n.ProvidedBy()[0]},
+					Provider: &provider,
 					State:    &state,
 					Output:   &state,
 				},
@@ -210,9 +215,13 @@ func (n *graphNodeOrphanResource) EvalTree() EvalNode {
 		Ops: []walkOperation{walkPlan, walkPlanDestroy},
 		Node: &EvalSequence{
 			Nodes: []EvalNode{
+				&EvalReadState{
+					Name:   n.ResourceName,
+					Output: &state,
+				},
 				&EvalDiffDestroy{
 					Info:   info,
-					State:  &EvalReadState{Name: n.ResourceName},
+					State:  &state,
 					Output: &diff,
 				},
 				&EvalWriteDiff{
@@ -224,7 +233,6 @@ func (n *graphNodeOrphanResource) EvalTree() EvalNode {
 	})
 
 	// Apply
-	var provider ResourceProvider
 	seq.Nodes = append(seq.Nodes, &EvalOpFilter{
 		Ops: []walkOperation{walkApply},
 		Node: &EvalSequence{

terraform/transform_resource.go

@@ -99,6 +99,8 @@ func (n *graphNodeExpandedResource) ProvidedBy() []string {
 // GraphNodeEvalable impl.
 func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 	var diff *InstanceDiff
+	var provider ResourceProvider
+	var resourceConfig *ResourceConfig
 	var state *InstanceState
 
 	// Build the resource. If we aren't part of a multi-resource, then
@@ -109,29 +111,35 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 	}
 	resource := &Resource{CountIndex: index}
 
-	// Shared node for interpolation of configuration
-	interpolateNode := &EvalInterpolate{
-		Config:   n.Resource.RawConfig,
-		Resource: resource,
-	}
-
 	seq := &EvalSequence{Nodes: make([]EvalNode, 0, 5)}
 
 	// Validate the resource
 	vseq := &EvalSequence{Nodes: make([]EvalNode, 0, 5)}
+	vseq.Nodes = append(vseq.Nodes, &EvalGetProvider{
+		Name:   n.ProvidedBy()[0],
+		Output: &provider,
+	})
+	vseq.Nodes = append(vseq.Nodes, &EvalInterpolate{
+		Config:   n.Resource.RawConfig,
+		Resource: resource,
+		Output:   &resourceConfig,
+	})
 	vseq.Nodes = append(vseq.Nodes, &EvalValidateResource{
-		Provider:     &EvalGetProvider{Name: n.ProvidedBy()[0]},
+		Provider:     &provider,
-		Config:       interpolateNode,
+		Config:       &resourceConfig,
 		ResourceName: n.Resource.Name,
 		ResourceType: n.Resource.Type,
 	})
 
 	// Validate all the provisioners
 	for _, p := range n.Resource.Provisioners {
-		vseq.Nodes = append(vseq.Nodes, &EvalValidateProvisioner{
+		var provisioner ResourceProvisioner
-			Provisioner: &EvalGetProvisioner{Name: p.Type},
+		vseq.Nodes = append(vseq.Nodes, &EvalGetProvisioner{
-			Config: &EvalInterpolate{
+			Name:   p.Type,
-				Config: p.RawConfig, Resource: resource},
+			Output: &provisioner,
+		}, &EvalValidateProvisioner{
+			Provisioner: &provisioner,
+			Config:      &resourceConfig,
 		})
 	}
 
@@ -150,13 +158,17 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 		Ops: []walkOperation{walkRefresh},
 		Node: &EvalSequence{
 			Nodes: []EvalNode{
+				&EvalGetProvider{
+					Name:   n.ProvidedBy()[0],
+					Output: &provider,
+				},
 				&EvalReadState{
 					Name:   n.stateId(),
 					Output: &state,
 				},
 				&EvalRefresh{
 					Info:     info,
-					Provider: &EvalGetProvider{Name: n.ProvidedBy()[0]},
+					Provider: &provider,
 					State:    &state,
 					Output:   &state,
 				},
@@ -175,11 +187,24 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 		Ops: []walkOperation{walkPlan},
 		Node: &EvalSequence{
 			Nodes: []EvalNode{
+				&EvalInterpolate{
+					Config:   n.Resource.RawConfig,
+					Resource: resource,
+					Output:   &resourceConfig,
+				},
+				&EvalGetProvider{
+					Name:   n.ProvidedBy()[0],
+					Output: &provider,
+				},
+				&EvalReadState{
+					Name:   n.stateId(),
+					Output: &state,
+				},
 				&EvalDiff{
 					Info:        info,
-					Config:      interpolateNode,
+					Config:      &resourceConfig,
-					Provider:    &EvalGetProvider{Name: n.ProvidedBy()[0]},
+					Provider:    &provider,
-					State:       &EvalReadState{Name: n.stateId()},
+					State:       &state,
 					Output:      &diff,
 					OutputState: &state,
 				},
@@ -206,9 +231,13 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 		Ops: []walkOperation{walkPlanDestroy},
 		Node: &EvalSequence{
 			Nodes: []EvalNode{
+				&EvalReadState{
+					Name:   n.stateId(),
+					Output: &state,
+				},
 				&EvalDiffDestroy{
 					Info:   info,
-					State:  &EvalReadState{Name: n.stateId()},
+					State:  &state,
 					Output: &diff,
 				},
 				&EvalWriteDiff{
@@ -220,7 +249,6 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 	})
 
 	// Diff the resource for destruction
-	var provider ResourceProvider
 	var diffApply *InstanceDiff
 	var err error
 	var createNew, tainted bool
@@ -260,11 +288,25 @@ func (n *graphNodeExpandedResource) EvalTree() EvalNode {
 					},
 				},
 
+				&EvalInterpolate{
+					Config:   n.Resource.RawConfig,
+					Resource: resource,
+					Output:   &resourceConfig,
+				},
+				&EvalGetProvider{
+					Name:   n.ProvidedBy()[0],
+					Output: &provider,
+				},
+				&EvalReadState{
+					Name:   n.stateId(),
+					Output: &state,
+				},
+
 				&EvalDiff{
 					Info:     info,
-					Config:   interpolateNode,
+					Config:   &resourceConfig,
-					Provider: &EvalGetProvider{Name: n.ProvidedBy()[0]},
+					Provider: &provider,
-					State:    &EvalReadState{Name: n.stateId()},
+					State:    &state,
 					Output:   &diffApply,
 				},
 

terraform/transform_tainted.go

@@ -68,6 +68,7 @@ func (n *graphNodeTaintedResource) ProvidedBy() []string {
 
 // GraphNodeEvalable impl.
 func (n *graphNodeTaintedResource) EvalTree() EvalNode {
+	var provider ResourceProvider
 	var state *InstanceState
 	tainted := true
 
@@ -82,6 +83,10 @@ func (n *graphNodeTaintedResource) EvalTree() EvalNode {
 		Ops: []walkOperation{walkRefresh},
 		Node: &EvalSequence{
 			Nodes: []EvalNode{
+				&EvalGetProvider{
+					Name:   n.ProvidedBy()[0],
+					Output: &provider,
+				},
 				&EvalReadState{
 					Name:         n.ResourceName,
 					Tainted:      true,
@@ -90,7 +95,7 @@ func (n *graphNodeTaintedResource) EvalTree() EvalNode {
 				},
 				&EvalRefresh{
 					Info:     info,
-					Provider: &EvalGetProvider{Name: n.ProvidedBy()[0]},
+					Provider: &provider,
 					State:    &state,
 					Output:   &state,
 				},
@@ -106,7 +111,6 @@ func (n *graphNodeTaintedResource) EvalTree() EvalNode {
 	})
 
 	// Apply
-	var provider ResourceProvider
 	var diff *InstanceDiff
 	seq.Nodes = append(seq.Nodes, &EvalOpFilter{
 		Ops: []walkOperation{walkApply},
@@ -124,11 +128,7 @@ func (n *graphNodeTaintedResource) EvalTree() EvalNode {
 				},
 				&EvalDiffDestroy{
 					Info:   info,
-					State: &EvalReadState{
+					State:  &state,
-						Name:         n.ResourceName,
-						Tainted:      true,
-						TaintedIndex: n.Index,
-					},
 					Output: &diff,
 				},
 				&EvalApply{