config: parser fixes and application

config/expr.y

@@ -35,7 +35,7 @@ import (
 top:
 	expr
 	{
-		fmt.Printf("%#v", $1)
+		exprResult = $1
 	}
 
 expr:
@@ -49,7 +49,13 @@ expr:
 	}
 |	IDENTIFIER LEFTPAREN args RIGHTPAREN
 	{
-		$$ = &FunctionInterpolation{Func: $1, Args: $3}
+		f, ok := Funcs[$1]
+		if !ok {
+			exprErrors = append(exprErrors, fmt.Errorf(
+				"Unknown function: %s", $1))
+		}
+
+		$$ = &FunctionInterpolation{Func: f, Args: $3}
 	}
 
 args:

config/expr_lex.go

@@ -58,6 +58,7 @@ func (x *exprLex) lexId(yylval *exprSymType) int {
 		// If this isn't a character we want in an ID, return out.
 		// One day we should make this a regexp.
 		if c != '_' &&
+			c != '-' &&
 			c != '.' &&
 			c != '*' &&
 			!unicode.IsLetter(c) &&

config/expr_parse.go

@@ -0,0 +1,34 @@
+package config
+
+import (
+	"sync"
+
+	"github.com/hashicorp/terraform/helper/multierror"
+)
+
+// exprErrors are the errors built up from parsing. These should not
+// be accessed directly.
+var exprErrors []error
+var exprLock sync.Mutex
+var exprResult Interpolation
+
+// ExprParse parses the given expression and returns an executable
+// Interpolation.
+func ExprParse(v string) (Interpolation, error) {
+	exprLock.Lock()
+	defer exprLock.Unlock()
+	exprErrors = nil
+	exprResult = nil
+
+	// Parse
+	exprParse(&exprLex{input: v})
+
+	// Build up the errors
+	var err error
+	if len(exprErrors) > 0 {
+		err = &multierror.Error{Errors: exprErrors}
+		exprResult = nil
+	}
+
+	return exprResult, err
+}

config/interpolate.go

@@ -17,7 +17,6 @@ var funcRegexp *regexp.Regexp = regexp.MustCompile(
 // Interpolations might be simple variable references, or it might be
 // function calls, or even nested function calls.
 type Interpolation interface {
-	FullString() string
 	Interpolate(map[string]string) (string, error)
 	Variables() map[string]InterpolatedVariable
 }
@@ -37,26 +36,20 @@ type InterpolatedVariable interface {
 // FunctionInterpolation is an Interpolation that executes a function
 // with some variable number of arguments to generate a value.
 type FunctionInterpolation struct {
-	Func string
+	Func InterpolationFunc
 	Args []Interpolation
-
-	key string
 }
 
 // LiteralInterpolation implements Interpolation for literals. Ex:
 // ${"foo"} will equal "foo".
 type LiteralInterpolation struct {
 	Literal string
-
-	key string
 }
 
 // VariableInterpolation implements Interpolation for simple variable
 // interpolation. Ex: "${var.foo}" or "${aws_instance.foo.bar}"
 type VariableInterpolation struct {
 	Variable InterpolatedVariable
-
-	key string
 }
 
 // A ResourceVariable is a variable that is referencing the field
@@ -82,61 +75,6 @@ type UserVariable struct {
 	key string
 }
 
-// NewInterpolation takes some string and returns the valid
-// Interpolation associated with it, or error if a valid
-// interpolation could not be found or the interpolation itself
-// is invalid.
-func NewInterpolation(v string) (Interpolation, error) {
-	match := funcRegexp.FindStringSubmatch(v)
-	if match != nil {
-		fn, ok := Funcs[match[1]]
-		if !ok {
-			return nil, fmt.Errorf(
-				"%s: Unknown function '%s'",
-				v, match[1])
-		}
-
-		args := make([]InterpolatedVariable, 0, len(match)-2)
-		for i := 2; i < len(match); i++ {
-			// This can be empty if we have a single argument
-			// due to the format of the regexp.
-			if match[i] == "" {
-				continue
-			}
-
-			v, err := NewInterpolatedVariable(match[i])
-			if err != nil {
-				return nil, err
-			}
-
-			args = append(args, v)
-		}
-
-		return &FunctionInterpolation{
-			Func: fn,
-			Args: args,
-
-			key: v,
-		}, nil
-	}
-
-	if idx := strings.Index(v, "."); idx >= 0 {
-		v, err := NewInterpolatedVariable(v)
-		if err != nil {
-			return nil, err
-		}
-
-		return &VariableInterpolation{
-			Variable: v,
-			key:      v.FullKey(),
-		}, nil
-	}
-
-	return nil, fmt.Errorf(
-		"Interpolation '%s' is not a valid interpolation. " +
-			"Please check your syntax and try again.")
-}
-
 func NewInterpolatedVariable(v string) (InterpolatedVariable, error) {
 	if !strings.HasPrefix(v, "var.") {
 		return NewResourceVariable(v)
@@ -145,21 +83,13 @@ func NewInterpolatedVariable(v string) (InterpolatedVariable, error) {
 	return NewUserVariable(v)
 }
 
-func (i *FunctionInterpolation) FullString() string {
-	return i.key
-}
-
 func (i *FunctionInterpolation) Interpolate(
 	vs map[string]string) (string, error) {
 	args := make([]string, len(i.Args))
 	for idx, a := range i.Args {
-		k := a.FullKey()
+		v, err := a.Interpolate(vs)
-		v, ok := vs[k]
+		if err != nil {
-		if !ok {
+			return "", err
-			return "", fmt.Errorf(
-				"%s: variable argument value unknown: %s",
-				i.FullString(),
-				k)
 		}
 
 		args[idx] = v
@@ -171,21 +101,14 @@ func (i *FunctionInterpolation) Interpolate(
 func (i *FunctionInterpolation) Variables() map[string]InterpolatedVariable {
 	result := make(map[string]InterpolatedVariable)
 	for _, a := range i.Args {
-		k := a.FullKey()
+		for k, v := range a.Variables() {
-		if _, ok := result[k]; ok {
+			result[k] = v
-			continue
 		}
-
-		result[k] = a
 	}
 
 	return result
 }
 
-func (i *LiteralInterpolation) FullString() string {
-	return i.key
-}
-
 func (i *LiteralInterpolation) Interpolate(
 	map[string]string) (string, error) {
 	return i.Literal, nil
@@ -195,24 +118,20 @@ func (i *LiteralInterpolation) Variables() map[string]InterpolatedVariable {
 	return nil
 }
 
-func (i *VariableInterpolation) FullString() string {
-	return i.key
-}
-
 func (i *VariableInterpolation) Interpolate(
 	vs map[string]string) (string, error) {
-	v, ok := vs[i.key]
+	v, ok := vs[i.Variable.FullKey()]
 	if !ok {
 		return "", fmt.Errorf(
 			"%s: value for variable not found",
-			i.key)
+			i.Variable.FullKey())
 	}
 
 	return v, nil
 }
 
 func (i *VariableInterpolation) Variables() map[string]InterpolatedVariable {
-	return map[string]InterpolatedVariable{i.key: i.Variable}
+	return map[string]InterpolatedVariable{i.Variable.FullKey(): i.Variable}
 }
 
 func NewResourceVariable(key string) (*ResourceVariable, error) {

config/interpolate_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 )
 
+/*
 func TestNewInterpolation(t *testing.T) {
 	cases := []struct {
 		Input  string
@@ -67,6 +68,7 @@ func TestNewInterpolation(t *testing.T) {
 		}
 	}
 }
+*/
 
 func TestNewInterpolatedVariable(t *testing.T) {
 	cases := []struct {
@@ -171,11 +173,10 @@ func TestFunctionInterpolation(t *testing.T) {
 
 	i := &FunctionInterpolation{
 		Func: fn,
-		Args: []InterpolatedVariable{v1, v2},
+		Args: []Interpolation{
-		key:  "foo",
+			&VariableInterpolation{Variable: v1},
-	}
+			&VariableInterpolation{Variable: v2},
-	if i.FullString() != "foo" {
+		},
-		t.Fatalf("err: %#v", i)
 	}
 
 	expected := map[string]InterpolatedVariable{
@@ -206,10 +207,6 @@ func TestLiteralInterpolation_impl(t *testing.T) {
 func TestLiteralInterpolation(t *testing.T) {
 	i := &LiteralInterpolation{
 		Literal: "bar",
-		key:     "foo",
-	}
-	if i.FullString() != "foo" {
-		t.Fatalf("err: %#v", i)
 	}
 
 	if i.Variables() != nil {
@@ -292,10 +289,7 @@ func TestVariableInterpolation(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 
-	i := &VariableInterpolation{Variable: uv, key: "var.foo"}
+	i := &VariableInterpolation{Variable: uv}
-	if i.FullString() != "var.foo" {
-		t.Fatalf("err: %#v", i)
-	}
 
 	expected := map[string]InterpolatedVariable{"var.foo": uv}
 	if !reflect.DeepEqual(i.Variables(), expected) {
@@ -320,7 +314,7 @@ func TestVariableInterpolation_missing(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 
-	i := &VariableInterpolation{Variable: uv, key: "var.foo"}
+	i := &VariableInterpolation{Variable: uv}
 	_, err = i.Interpolate(map[string]string{
 		"var.bar": "bar",
 	})

config/interpolate_walk.go

@@ -95,7 +95,7 @@ func (w *interpolationWalker) Primitive(v reflect.Value) error {
 		// Interpolation found, instantiate it
 		key := match[2]
 
-		i, err := NewInterpolation(key)
+		i, err := ExprParse(key)
 		if err != nil {
 			return err
 		}

config/interpolate_walk_test.go

@@ -29,7 +29,6 @@ func TestInterpolationWalker_detect(t *testing.T) {
 						Name: "foo",
 						key:  "var.foo",
 					},
-					key: "var.foo",
 				},
 			},
 		},
@@ -41,13 +40,14 @@ func TestInterpolationWalker_detect(t *testing.T) {
 			Result: []Interpolation{
 				&FunctionInterpolation{
 					Func: nil,
-					Args: []InterpolatedVariable{
+					Args: []Interpolation{
-						&UserVariable{
+						&VariableInterpolation{
+							Variable: &UserVariable{
 								Name: "foo",
 								key:  "var.foo",
 							},
 						},
-					key: "lookup(var.foo)",
+					},
 				},
 			},
 		},