Unmarshal ints and floats

internal/ast/ast.go

@@ -158,11 +158,43 @@ func (n *Node) Key() []Node {
 // Guaranteed to be non-nil.
 // Panics if not called on a KeyValue node, or if the Children are malformed.
 func (n *Node) Value() *Node {
-	if n.Kind != KeyValue {
-		panic(fmt.Errorf("Key() should only be called on on a KeyValue, not %s", n.Kind))
-	}
+	assertKind(KeyValue, n)
 	if len(n.Children) < 2 {
 		panic(fmt.Errorf("KeyValue should have at least two children, not %d", len(n.Children)))
 	}
 	return &n.Children[len(n.Children)-1]
 }
+
+// DecodeInteger parse the data of an Integer node and returns the represented
+// int64, or an error.
+// Panics if not called on an Integer node.
+func (n *Node) DecodeInteger() (int64, error) {
+	assertKind(Integer, n)
+	if len(n.Data) > 2 && n.Data[0] == '0' {
+		switch n.Data[1] {
+		case 'x':
+			return parseIntHex(n.Data)
+		case 'b':
+			return parseIntBin(n.Data)
+		case 'o':
+			return parseIntOct(n.Data)
+		default:
+			return 0, fmt.Errorf("invalid base: '%c'", n.Data[1])
+		}
+	}
+	return parseIntDec(n.Data)
+}
+
+// DecodeFloat parse the data of a Float node and returns the represented
+// float64, or an error.
+// Panics if not called on an Float node.
+func (n *Node) DecodeFloat() (float64, error) {
+	assertKind(Float, n)
+	return parseFloat(n.Data)
+}
+
+func assertKind(k Kind, n *Node) {
+	if n.Kind != k {
+		panic(fmt.Errorf("method was expecting a %s, not a %s", k, n.Kind))
+	}
+}