go-common/app/admin/ep/melloi/service/proto/comment.go
2019-04-22 18:49:16 +08:00

147 lines
4.6 KiB
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 (
"strings"
"text/scanner"
)
// Comment one or more comment text lines, either in c- or c++ style.
type Comment struct {
Position scanner.Position
// Lines are comment text lines without prefixes //, ///, /* or suffix */
Lines []string
Cstyle bool // refers to /* ... */, C++ style is using //
ExtraSlash bool // is true if the comment starts with 3 slashes
}
// newComment returns a comment.
func newComment(pos scanner.Position, lit string) *Comment {
extraSlash := strings.HasPrefix(lit, "///")
isCstyle := strings.HasPrefix(lit, "/*") && strings.HasSuffix(lit, "*/")
var lines []string
if isCstyle {
withoutMarkers := strings.TrimRight(strings.TrimLeft(lit, "/*"), "*/")
lines = strings.Split(withoutMarkers, "\n")
} else {
lines = strings.Split(strings.TrimLeft(lit, "/"), "\n")
}
return &Comment{Position: pos, Lines: lines, Cstyle: isCstyle, ExtraSlash: extraSlash}
}
//type inlineComment struct {
// line string
// extraSlash bool
//}
// Accept dispatches the call to the visitor.
func (c *Comment) Accept(v Visitor) {
v.VisitComment(c)
}
// Merge appends all lines from the argument comment.
func (c *Comment) Merge(other *Comment) {
c.Lines = append(c.Lines, other.Lines...)
c.Cstyle = c.Cstyle || other.Cstyle
}
func (c Comment) hasTextOnLine(line int) bool {
if len(c.Lines) == 0 {
return false
}
return c.Position.Line <= line && line <= c.Position.Line+len(c.Lines)-1
}
// Message returns the first line or empty if no lines.
func (c Comment) Message() string {
if len(c.Lines) == 0 {
return ""
}
return c.Lines[0]
}
// commentInliner is for types that can have an inline comment.
type commentInliner interface {
inlineComment(c *Comment)
}
// maybeScanInlineComment tries to scan comment on the current line ; if present then set it for the last element added.
func maybeScanInlineComment(p *Parser, c elementContainer) {
currentPos := p.scanner.Position
// see if there is an inline Comment
pos, tok, lit := p.next()
esize := len(c.elements())
// seen comment and on same line and elements have been added
if tCOMMENT == tok && pos.Line == currentPos.Line && esize > 0 {
// if the last added element can have an inline comment then set it
last := c.elements()[esize-1]
if inliner, ok := last.(commentInliner); ok {
// TODO skip multiline?
inliner.inlineComment(newComment(pos, lit))
}
} else {
p.nextPut(pos, tok, lit)
}
}
// takeLastCommentIfEndsOnLine removes and returns the last element of the list if it is a Comment
func takeLastCommentIfEndsOnLine(list []Visitee, line int) (*Comment, []Visitee) {
if len(list) == 0 {
return nil, list
}
if last, ok := list[len(list)-1].(*Comment); ok && last.hasTextOnLine(line) {
return last, list[:len(list)-1]
}
return nil, list
}
// mergeOrReturnComment creates a new comment and tries to merge it with the last element (if is a comment and is on the next line).
func mergeOrReturnComment(elements []Visitee, lit string, pos scanner.Position) *Comment {
com := newComment(pos, lit)
esize := len(elements)
if esize == 0 {
return com
}
// last element must be a comment to merge
last, ok := elements[esize-1].(*Comment)
if !ok {
return com
}
// do not merge c-style comments
if last.Cstyle {
return com
}
// last comment has text on previous line
// TODO handle last line of file could be inline comment
if !last.hasTextOnLine(pos.Line - 1) {
return com
}
last.Merge(com)
return nil
}
// parent is part of elementContainer
func (c *Comment) parent(Visitee) {}