config/lang: AST String() methods

config/lang/ast/ast.go

@@ -37,7 +37,7 @@ type Type uint
 
 const (
 	TypeInvalid Type = 0
-	TypeString       = 1 << iota
+	TypeString  Type = 1 << iota
 	TypeInt
 	TypeFloat
 )

config/lang/ast/call.go

@@ -1,5 +1,10 @@
 package ast
 
+import (
+	"fmt"
+	"strings"
+)
+
 // Call represents a function call.
 type Call struct {
 	Func string
@@ -18,3 +23,12 @@ func (n *Call) Accept(v Visitor) {
 func (n *Call) Pos() Pos {
 	return n.Posx
 }
+
+func (n *Call) String() string {
+	args := make([]string, len(n.Args))
+	for i, arg := range n.Args {
+		args[i] = fmt.Sprintf("%s", arg)
+	}
+
+	return fmt.Sprintf("Call(%s, %s)", n.Func, strings.Join(args, ", "))
+}

config/lang/ast/literal.go

@@ -23,3 +23,7 @@ func (n *LiteralNode) Pos() Pos {
 func (n *LiteralNode) GoString() string {
 	return fmt.Sprintf("*%#v", *n)
 }
+
+func (n *LiteralNode) String() string {
+	return fmt.Sprintf("Literal(%s, %v)", n.Type, n.Value)
+}

config/lang/ast/type_string.go

@@ -4,13 +4,31 @@ package ast
 
 import "fmt"
 
-const _Type_name = "TypeInvalid"
+const (
+	_Type_name_0 = "TypeInvalid"
+	_Type_name_1 = "TypeString"
+	_Type_name_2 = "TypeInt"
+	_Type_name_3 = "TypeFloat"
+)
 
-var _Type_index = [...]uint8{0, 11}
+var (
+	_Type_index_0 = [...]uint8{0, 11}
+	_Type_index_1 = [...]uint8{0, 10}
+	_Type_index_2 = [...]uint8{0, 7}
+	_Type_index_3 = [...]uint8{0, 9}
+)
 
 func (i Type) String() string {
-	if i+1 >= Type(len(_Type_index)) {
+	switch {
+	case i == 0:
+		return _Type_name_0
+	case i == 2:
+		return _Type_name_1
+	case i == 4:
+		return _Type_name_2
+	case i == 8:
+		return _Type_name_3
+	default:
 		return fmt.Sprintf("Type(%d)", i)
 	}
-	return _Type_name[_Type_index[i]:_Type_index[i+1]]
 }

config/lang/ast/variable_access.go

@@ -21,3 +21,7 @@ func (n *VariableAccess) Pos() Pos {
 func (n *VariableAccess) GoString() string {
 	return fmt.Sprintf("*%#v", *n)
 }
+
+func (n *VariableAccess) String() string {
+	return fmt.Sprintf("Variable(%s)", n.Name)
+}

config/lang/parse_test.go

@@ -23,6 +23,16 @@ func TestParse(t *testing.T) {
 			},
 		},
 
+		{
+			"$${var.foo}",
+			false,
+			&ast.LiteralNode{
+				Value: "${var.foo}",
+				Type:  ast.TypeString,
+				Posx:  ast.Pos{Column: 1, Line: 1},
+			},
+		},
+
 		{
 			"foo ${var.bar}",
 			false,