Skip to content
This repository
Fetching contributors…

Cannot retrieve contributors at this time

file 134 lines (110 sloc) 2.733 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134
package main

import (
"go/scanner"
"go/token"
)

// All the code in this file serves single purpose:
// It separates a function with the cursor inside and the rest of the code. I'm
// doing that, because sometimes parser is not able to recover itself from an
// error and the autocompletion results become less complete.

type tok_pos_pair struct {
tok token.Token
pos token.Pos
}

type tok_collection struct {
tokens []tok_pos_pair
fset *token.FileSet
}

func (this *tok_collection) next(s *scanner.Scanner) bool {
pos, tok, _ := s.Scan()
if tok == token.EOF {
return false
}

this.tokens = append(this.tokens, tok_pos_pair{tok, pos})
return true
}

func (this *tok_collection) find_decl_beg(pos int) int {
lowest := 0
lowpos := -1
lowi := -1
cur := 0
for i := pos; i >= 0; i-- {
t := this.tokens[i]
switch t.tok {
case token.RBRACE:
cur++
case token.LBRACE:
cur--
}

if cur < lowest {
lowest = cur
lowpos = this.fset.Position(t.pos).Offset
lowi = i
}
}

for i := lowi; i >= 0; i-- {
t := this.tokens[i]
if t.tok == token.SEMICOLON {
lowpos = this.fset.Position(t.pos).Offset
break
}
}

return lowpos
}

func (this *tok_collection) find_decl_end(pos int) int {
highest := 0
highpos := -1
cur := 0

if this.tokens[pos].tok == token.LBRACE {
pos++
}

for i := pos; i < len(this.tokens); i++ {
t := this.tokens[i]
switch t.tok {
case token.RBRACE:
cur++
case token.LBRACE:
cur--
}

if cur > highest {
highest = cur
highpos = this.fset.Position(t.pos).Offset
}
}

return highpos
}

func (this *tok_collection) find_outermost_scope(cursor int) (int, int) {
pos := 0

for i, t := range this.tokens {
if cursor <= this.fset.Position(t.pos).Offset {
break
}
pos = i
}

return this.find_decl_beg(pos), this.find_decl_end(pos)
}

// return new cursor position, file without ripped part and the ripped part itself
// variants:
// new-cursor, file-without-ripped-part, ripped-part
// old-cursor, file, nil
func (this *tok_collection) rip_off_decl(file []byte, cursor int) (int, []byte, []byte) {
this.fset = token.NewFileSet()
var s scanner.Scanner
s.Init(this.fset.AddFile("", this.fset.Base(), len(file)), file, nil, scanner.ScanComments)
for this.next(&s) {
}

beg, end := this.find_outermost_scope(cursor)
if beg == -1 || end == -1 {
return cursor, file, nil
}

ripped := make([]byte, end+1-beg)
copy(ripped, file[beg:end+1])

newfile := make([]byte, len(file)-len(ripped))
copy(newfile, file[:beg])
copy(newfile[beg:], file[end+1:])

return cursor - beg, newfile, ripped
}

func rip_off_decl(file []byte, cursor int) (int, []byte, []byte) {
var tc tok_collection
return tc.rip_off_decl(file, cursor)
}
Something went wrong with that request. Please try again.