1 package repl
2
3 import (
4 `go/scanner`
5 `go/token`
6 `strconv`
7 )
8
9 type _SyntaxError string
10
11 func (self _SyntaxError) Error() string {
12 return string(self)
13 }
14
15 type _Scanner struct {
16 val string
17 tok token.Token
18 lex scanner.Scanner
19 }
20
21 const (
22 dontInsertSemis scanner.Mode = 2
23 )
24
25 func scan(cmd string) (p *_Scanner) {
26 p = new(_Scanner)
27 p.lex.Init(token.NewFileSet().AddFile("(REPL)", 1, len(cmd)), []byte(cmd), nil, dontInsertSemis)
28 p.next()
29 return
30 }
31
32 func (self *_Scanner) next() {
33 _, self.tok, self.val = self.lex.Scan()
34 }
35
36 func (self *_Scanner) must(tok token.Token) {
37 if self.tok == token.EOF {
38 panic(_SyntaxError("unexpected EOF"))
39 } else if self.tok != tok {
40 panic(_SyntaxError(tok.String() + " required"))
41 }
42 }
43
44 func (self *_Scanner) close() {
45 if self.tok != token.EOF {
46 panic(_SyntaxError("excess parameters"))
47 }
48 }
49
50 func (self *_Scanner) str(v *string) *_Scanner {
51 self.must(token.STRING)
52 *v, _ = strconv.Unquote(self.val)
53 self.next()
54 return self
55 }
56
57 func (self *_Scanner) uint(v *uint64) *_Scanner {
58 self.must(token.INT)
59 *v, _ = strconv.ParseUint(self.val, 0, 64)
60 self.next()
61 return self
62 }
63
64 func (self *_Scanner) idoff(id *uint64, offs *uint64) *_Scanner {
65 self.must(token.INT)
66 *id, _ = strconv.ParseUint(self.val, 0, 64)
67 self.next()
68
69
70 if self.tok != token.ADD {
71 return self
72 }
73
74
75 self.next()
76 self.must(token.INT)
77 *offs, _ = strconv.ParseUint(self.val, 0, 64)
78 self.next()
79 return self
80 }
81
82 func (self *_Scanner) uintopt(v *uint64) *_Scanner {
83 if self.tok != token.INT {
84 return self
85 } else {
86 *v, _ = strconv.ParseUint(self.val, 0, 64)
87 self.next()
88 return self
89 }
90 }
91
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