.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201105173854-bc9fc8d8c4bc/godoc/tab.go

   1 // Copyright 2013 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // TODO(bradfitz,adg): move to util
   6
   7 package godoc
   8
   9 import "io"
  10
  11 var spaces = []byte("                                ") // 32 spaces seems like a good number
  12
  13 const (
  14         indenting = iota
  15         collecting
  16 )
  17
  18 // A tconv is an io.Writer filter for converting leading tabs into spaces.
  19 type tconv struct {
  20         output io.Writer
  21         state  int // indenting or collecting
  22         indent int // valid if state == indenting
  23         p      *Presentation
  24 }
  25
  26 func (p *tconv) writeIndent() (err error) {
  27         i := p.indent
  28         for i >= len(spaces) {
  29                 i -= len(spaces)
  30                 if _, err = p.output.Write(spaces); err != nil {
  31                         return
  32                 }
  33         }
  34         // i < len(spaces)
  35         if i > 0 {
  36                 _, err = p.output.Write(spaces[0:i])
  37         }
  38         return
  39 }
  40
  41 func (p *tconv) Write(data []byte) (n int, err error) {
  42         if len(data) == 0 {
  43                 return
  44         }
  45         pos := 0 // valid if p.state == collecting
  46         var b byte
  47         for n, b = range data {
  48                 switch p.state {
  49                 case indenting:
  50                         switch b {
  51                         case '\t':
  52                                 p.indent += p.p.TabWidth
  53                         case '\n':
  54                                 p.indent = 0
  55                                 if _, err = p.output.Write(data[n : n+1]); err != nil {
  56                                         return
  57                                 }
  58                         case ' ':
  59                                 p.indent++
  60                         default:
  61                                 p.state = collecting
  62                                 pos = n
  63                                 if err = p.writeIndent(); err != nil {
  64                                         return
  65                                 }
  66                         }
  67                 case collecting:
  68                         if b == '\n' {
  69                                 p.state = indenting
  70                                 p.indent = 0
  71                                 if _, err = p.output.Write(data[pos : n+1]); err != nil {
  72                                         return
  73                                 }
  74                         }
  75                 }
  76         }
  77         n = len(data)
  78         if pos < n && p.state == collecting {
  79                 _, err = p.output.Write(data[pos:])
  80         }
  81         return
  82 }