reserved.go

// Copyright (c) 2017 Ernest Micklei
//
// MIT License
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

package proto

import "text/scanner"

// Reserved statements declare a range of field numbers or field names that cannot be used in a message.
type Reserved struct {
	Position      scanner.Position
	Comment       *Comment
	Ranges        []Range
	FieldNames    []string
	InlineComment *Comment
	Parent        Visitee
}

// inlineComment is part of commentInliner.
func (r *Reserved) inlineComment(c *Comment) {
	r.InlineComment = c
}

// Accept dispatches the call to the visitor.
func (r *Reserved) Accept(v Visitor) {
	v.VisitReserved(r)
}

func (r *Reserved) parse(p *Parser) error {
	for {
		pos, tok, lit := p.next()
		if len(lit) == 0 {
			return p.unexpected(lit, "reserved string or integer", r)
		}
		// first char that determined tok
		ch := []rune(lit)[0]
		if isDigit(ch) {
			// use unread here because it could be start of ranges
			p.nextPut(pos, tok, lit)
			list, err := parseRanges(p, r)
			if err != nil {
				return err
			}
			r.Ranges = list
			continue
		}
		if isString(lit) {
			r.FieldNames = append(r.FieldNames, unQuote(lit))
			continue
		}
		if tSEMICOLON == tok {
			p.nextPut(pos, tok, lit)
			break
		}
	}
	return nil
}

func (r *Reserved) parent(v Visitee) { r.Parent = v }