fixed dependencies

vendor/github.com/go-latex/latex/scanner.go

@@ -0,0 +1,205 @@
+// Copyright ©2020 The go-latex Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package latex
+
+import (
+	"fmt"
+	"io"
+	"strings"
+	"text/scanner"
+	"unicode"
+
+	"github.com/go-latex/latex/token"
+)
+
+type texScanner struct {
+	sc scanner.Scanner
+
+	r   rune
+	tok token.Token
+}
+
+func newScanner(r io.Reader) *texScanner {
+	sc := &texScanner{}
+	sc.sc.Init(r)
+	sc.sc.Mode = (scanner.ScanIdents | scanner.ScanInts | scanner.ScanFloats)
+	sc.sc.Mode |= scanner.ScanStrings
+	//scanner.ScanRawStrings)
+	//	sc.sc.Error = func(s *scanner.Scanner, msg string) {}
+	sc.sc.IsIdentRune = func(ch rune, i int) bool {
+		return unicode.IsLetter(ch) //|| unicode.IsDigit(ch) && i > 0
+	}
+	sc.sc.Whitespace = 1<<'\t' | 1<<'\n' | 1<<'\r'
+	return sc
+}
+
+// Token returns the most recently parsed token
+func (s *texScanner) Token() token.Token {
+	return s.tok
+}
+
+// Next iterates over all tokens.
+// Next retrieves the most recent token with Token().
+// It returns false once it reaches token.EOF.
+func (s *texScanner) Next() bool {
+	s.tok = s.scan()
+	return s.tok.Kind != token.EOF
+}
+
+func (s *texScanner) scan() token.Token {
+	s.next()
+	pos := s.pos()
+	switch s.r {
+	case scanner.Ident:
+		return token.Token{
+			Kind: token.Word,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+	case '\\':
+		nxt := s.sc.Peek()
+		switch nxt {
+		case ' ':
+			s.next()
+			return token.Token{
+				Kind: token.Space,
+				Pos:  pos,
+				Text: `\ `,
+			}
+		default:
+			return s.scanMacro()
+		}
+	case ' ':
+		return token.Token{
+			Kind: token.Space,
+			Pos:  pos,
+			Text: ` `,
+		}
+
+	case '%':
+		line := s.scanComment()
+		return token.Token{
+			Kind: token.Comment,
+			Pos:  pos,
+			Text: line,
+		}
+
+	case '$', '_', '=', '<', '>', '^', '/', '*', '-', '+',
+		'!', '?', '\'', ':', ',', ';', '.':
+		return token.Token{
+			Kind: token.Symbol,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+
+	case '[':
+		return token.Token{
+			Kind: token.Lbrack,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+	case ']':
+		return token.Token{
+			Kind: token.Rbrack,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+	case '{':
+		return token.Token{
+			Kind: token.Lbrace,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+	case '}':
+		return token.Token{
+			Kind: token.Rbrace,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+	case '(':
+		return token.Token{
+			Kind: token.Lparen,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+	case ')':
+		return token.Token{
+			Kind: token.Rparen,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+	case scanner.Int, scanner.Float:
+		return token.Token{
+			Kind: token.Number,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+	case scanner.String, scanner.Char:
+		return token.Token{
+			Kind: token.Other,
+			Pos:  pos,
+			Text: s.sc.TokenText(),
+		}
+	case scanner.EOF:
+		return token.Token{
+			Kind: token.EOF,
+			Pos:  pos,
+		}
+	default:
+		panic(fmt.Errorf("unhandled token: %v %v", scanner.TokenString(s.r), s.r))
+	}
+}
+
+func (s *texScanner) next() {
+	s.r = s.sc.Scan()
+}
+
+func (s *texScanner) scanMacro() token.Token {
+	var (
+		macro = new(strings.Builder)
+		pos   = s.pos()
+	)
+	s.next()
+	macro.WriteString(`\` + s.sc.TokenText())
+
+	return token.Token{
+		Kind: token.Macro,
+		Pos:  pos,
+		Text: macro.String(),
+	}
+}
+
+func (s *texScanner) scanComment() string {
+	comment := new(strings.Builder)
+	comment.WriteString("%")
+	wsp := s.sc.Whitespace
+	defer func() {
+		s.sc.Whitespace = wsp
+	}()
+	s.sc.Whitespace = 0
+
+	for {
+		s.next()
+		if s.r == '\r' {
+			continue
+		}
+		if s.r == '\n' || s.r == scanner.EOF {
+			break
+		}
+		comment.WriteString(s.sc.TokenText())
+	}
+	return comment.String()
+}
+
+// func (s *texScanner) expect(want rune) {
+// 	s.next()
+// 	if s.r != want {
+// 		panic(fmt.Errorf("invalid rune: got=%q, want=%q", s.r, want))
+// 	}
+// }
+
+func (s *texScanner) pos() token.Pos {
+	return token.Pos(s.sc.Position.Offset)
+}