// Copyright (C) 2014 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package parse

// Node is a Fragment in a cst that represents unskipped tokens.
type Node interface {
	Fragment
	// Prefix returns the set of skippable fragments associated with this Node
	// that precede it in the stream. Association is defined by the Skip function
	// in use.
	Prefix() Separator
	// AddPrefix adds more fragments to the Prefix list.
	AddPrefix(Separator)
	// Suffix returns the set of skippable fragments associated with this Node
	// that follow it in the stream. Association is defined by the Skip function
	// in use, the default is until the end of the line.
	Suffix() Separator
	// AddSuffix adds more fragments to the Suffix list.
	AddSuffix(Separator)
}

type node struct {
	prefix Separator
	suffix Separator
}

func (n *node) Prefix() Separator {
	return n.prefix
}

func (n *node) AddPrefix(s Separator) {
	n.prefix = append(n.prefix, s...)
}

func (n *node) Suffix() Separator {
	return n.suffix
}

func (n *node) AddSuffix(s Separator) {
	n.suffix = append(n.suffix, s...)
}