diff options
Diffstat (limited to 'vendor/gopkg.in/gcfg.v1/scanner/scanner.go')
| -rw-r--r-- | vendor/gopkg.in/gcfg.v1/scanner/scanner.go | 342 |
1 files changed, 0 insertions, 342 deletions
diff --git a/vendor/gopkg.in/gcfg.v1/scanner/scanner.go b/vendor/gopkg.in/gcfg.v1/scanner/scanner.go deleted file mode 100644 index bbbdbf53..00000000 --- a/vendor/gopkg.in/gcfg.v1/scanner/scanner.go +++ /dev/null @@ -1,342 +0,0 @@ -// Copyright 2009 The Go 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 scanner implements a scanner for gcfg configuration text. -// It takes a []byte as source which can then be tokenized -// through repeated calls to the Scan method. -// -// Note that the API for the scanner package may change to accommodate new -// features or implementation changes in gcfg. -// -package scanner - -import ( - "fmt" - "path/filepath" - "unicode" - "unicode/utf8" -) - -import ( - "gopkg.in/gcfg.v1/token" -) - -// An ErrorHandler may be provided to Scanner.Init. If a syntax error is -// encountered and a handler was installed, the handler is called with a -// position and an error message. The position points to the beginning of -// the offending token. -// -type ErrorHandler func(pos token.Position, msg string) - -// A Scanner holds the scanner's internal state while processing -// a given text. It can be allocated as part of another data -// structure but must be initialized via Init before use. -// -type Scanner struct { - // immutable state - file *token.File // source file handle - dir string // directory portion of file.Name() - src []byte // source - err ErrorHandler // error reporting; or nil - mode Mode // scanning mode - - // scanning state - ch rune // current character - offset int // character offset - rdOffset int // reading offset (position after current character) - lineOffset int // current line offset - nextVal bool // next token is expected to be a value - - // public state - ok to modify - ErrorCount int // number of errors encountered -} - -// Read the next Unicode char into s.ch. -// s.ch < 0 means end-of-file. -// -func (s *Scanner) next() { - if s.rdOffset < len(s.src) { - s.offset = s.rdOffset - if s.ch == '\n' { - s.lineOffset = s.offset - s.file.AddLine(s.offset) - } - r, w := rune(s.src[s.rdOffset]), 1 - switch { - case r == 0: - s.error(s.offset, "illegal character NUL") - case r >= 0x80: - // not ASCII - r, w = utf8.DecodeRune(s.src[s.rdOffset:]) - if r == utf8.RuneError && w == 1 { - s.error(s.offset, "illegal UTF-8 encoding") - } - } - s.rdOffset += w - s.ch = r - } else { - s.offset = len(s.src) - if s.ch == '\n' { - s.lineOffset = s.offset - s.file.AddLine(s.offset) - } - s.ch = -1 // eof - } -} - -// A mode value is a set of flags (or 0). -// They control scanner behavior. -// -type Mode uint - -const ( - ScanComments Mode = 1 << iota // return comments as COMMENT tokens -) - -// Init prepares the scanner s to tokenize the text src by setting the -// scanner at the beginning of src. The scanner uses the file set file -// for position information and it adds line information for each line. -// It is ok to re-use the same file when re-scanning the same file as -// line information which is already present is ignored. Init causes a -// panic if the file size does not match the src size. -// -// Calls to Scan will invoke the error handler err if they encounter a -// syntax error and err is not nil. Also, for each error encountered, -// the Scanner field ErrorCount is incremented by one. The mode parameter -// determines how comments are handled. -// -// Note that Init may call err if there is an error in the first character -// of the file. -// -func (s *Scanner) Init(file *token.File, src []byte, err ErrorHandler, mode Mode) { - // Explicitly initialize all fields since a scanner may be reused. - if file.Size() != len(src) { - panic(fmt.Sprintf("file size (%d) does not match src len (%d)", file.Size(), len(src))) - } - s.file = file - s.dir, _ = filepath.Split(file.Name()) - s.src = src - s.err = err - s.mode = mode - - s.ch = ' ' - s.offset = 0 - s.rdOffset = 0 - s.lineOffset = 0 - s.ErrorCount = 0 - s.nextVal = false - - s.next() -} - -func (s *Scanner) error(offs int, msg string) { - if s.err != nil { - s.err(s.file.Position(s.file.Pos(offs)), msg) - } - s.ErrorCount++ -} - -func (s *Scanner) scanComment() string { - // initial [;#] already consumed - offs := s.offset - 1 // position of initial [;#] - - for s.ch != '\n' && s.ch >= 0 { - s.next() - } - return string(s.src[offs:s.offset]) -} - -func isLetter(ch rune) bool { - return 'a' <= ch && ch <= 'z' || 'A' <= ch && ch <= 'Z' || ch >= 0x80 && unicode.IsLetter(ch) -} - -func isDigit(ch rune) bool { - return '0' <= ch && ch <= '9' || ch >= 0x80 && unicode.IsDigit(ch) -} - -func (s *Scanner) scanIdentifier() string { - offs := s.offset - for isLetter(s.ch) || isDigit(s.ch) || s.ch == '-' { - s.next() - } - return string(s.src[offs:s.offset]) -} - -func (s *Scanner) scanEscape(val bool) { - offs := s.offset - ch := s.ch - s.next() // always make progress - switch ch { - case '\\', '"': - // ok - case 'n', 't': - if val { - break // ok - } - fallthrough - default: - s.error(offs, "unknown escape sequence") - } -} - -func (s *Scanner) scanString() string { - // '"' opening already consumed - offs := s.offset - 1 - - for s.ch != '"' { - ch := s.ch - s.next() - if ch == '\n' || ch < 0 { - s.error(offs, "string not terminated") - break - } - if ch == '\\' { - s.scanEscape(false) - } - } - - s.next() - - return string(s.src[offs:s.offset]) -} - -func stripCR(b []byte) []byte { - c := make([]byte, len(b)) - i := 0 - for _, ch := range b { - if ch != '\r' { - c[i] = ch - i++ - } - } - return c[:i] -} - -func (s *Scanner) scanValString() string { - offs := s.offset - - hasCR := false - end := offs - inQuote := false -loop: - for inQuote || s.ch >= 0 && s.ch != '\n' && s.ch != ';' && s.ch != '#' { - ch := s.ch - s.next() - switch { - case inQuote && ch == '\\': - s.scanEscape(true) - case !inQuote && ch == '\\': - if s.ch == '\r' { - hasCR = true - s.next() - } - if s.ch != '\n' { - s.error(offs, "unquoted '\\' must be followed by new line") - break loop - } - s.next() - case ch == '"': - inQuote = !inQuote - case ch == '\r': - hasCR = true - case ch < 0 || inQuote && ch == '\n': - s.error(offs, "string not terminated") - break loop - } - if inQuote || !isWhiteSpace(ch) { - end = s.offset - } - } - - lit := s.src[offs:end] - if hasCR { - lit = stripCR(lit) - } - - return string(lit) -} - -func isWhiteSpace(ch rune) bool { - return ch == ' ' || ch == '\t' || ch == '\r' -} - -func (s *Scanner) skipWhitespace() { - for isWhiteSpace(s.ch) { - s.next() - } -} - -// Scan scans the next token and returns the token position, the token, -// and its literal string if applicable. The source end is indicated by -// token.EOF. -// -// If the returned token is a literal (token.IDENT, token.STRING) or -// token.COMMENT, the literal string has the corresponding value. -// -// If the returned token is token.ILLEGAL, the literal string is the -// offending character. -// -// In all other cases, Scan returns an empty literal string. -// -// For more tolerant parsing, Scan will return a valid token if -// possible even if a syntax error was encountered. Thus, even -// if the resulting token sequence contains no illegal tokens, -// a client may not assume that no error occurred. Instead it -// must check the scanner's ErrorCount or the number of calls -// of the error handler, if there was one installed. -// -// Scan adds line information to the file added to the file -// set with Init. Token positions are relative to that file -// and thus relative to the file set. -// -func (s *Scanner) Scan() (pos token.Pos, tok token.Token, lit string) { -scanAgain: - s.skipWhitespace() - - // current token start - pos = s.file.Pos(s.offset) - - // determine token value - switch ch := s.ch; { - case s.nextVal: - lit = s.scanValString() - tok = token.STRING - s.nextVal = false - case isLetter(ch): - lit = s.scanIdentifier() - tok = token.IDENT - default: - s.next() // always make progress - switch ch { - case -1: - tok = token.EOF - case '\n': - tok = token.EOL - case '"': - tok = token.STRING - lit = s.scanString() - case '[': - tok = token.LBRACK - case ']': - tok = token.RBRACK - case ';', '#': - // comment - lit = s.scanComment() - if s.mode&ScanComments == 0 { - // skip comment - goto scanAgain - } - tok = token.COMMENT - case '=': - tok = token.ASSIGN - s.nextVal = true - default: - s.error(s.file.Offset(pos), fmt.Sprintf("illegal character %#U", ch)) - tok = token.ILLEGAL - lit = string(ch) - } - } - - return -} |