diff options
Diffstat (limited to 'vendor/github.com/tdewolff/parse/buffer/lexer.go')
-rw-r--r-- | vendor/github.com/tdewolff/parse/buffer/lexer.go | 158 |
1 files changed, 0 insertions, 158 deletions
diff --git a/vendor/github.com/tdewolff/parse/buffer/lexer.go b/vendor/github.com/tdewolff/parse/buffer/lexer.go deleted file mode 100644 index 45c1844..0000000 --- a/vendor/github.com/tdewolff/parse/buffer/lexer.go +++ /dev/null @@ -1,158 +0,0 @@ -package buffer // import "github.com/tdewolff/parse/buffer" - -import ( - "io" - "io/ioutil" -) - -var nullBuffer = []byte{0} - -// Lexer is a buffered reader that allows peeking forward and shifting, taking an io.Reader. -// It keeps data in-memory until Free, taking a byte length, is called to move beyond the data. -type Lexer struct { - buf []byte - pos int // index in buf - start int // index in buf - err error - - restore func() -} - -// NewLexerBytes returns a new Lexer for a given io.Reader, and uses ioutil.ReadAll to read it into a byte slice. -// If the io.Reader implements Bytes, that is used instead. -// It will append a NULL at the end of the buffer. -func NewLexer(r io.Reader) *Lexer { - var b []byte - if r != nil { - if buffer, ok := r.(interface { - Bytes() []byte - }); ok { - b = buffer.Bytes() - } else { - var err error - b, err = ioutil.ReadAll(r) - if err != nil { - return &Lexer{ - buf: []byte{0}, - err: err, - } - } - } - } - return NewLexerBytes(b) -} - -// NewLexerBytes returns a new Lexer for a given byte slice, and appends NULL at the end. -// To avoid reallocation, make sure the capacity has room for one more byte. -func NewLexerBytes(b []byte) *Lexer { - z := &Lexer{ - buf: b, - } - - n := len(b) - if n == 0 { - z.buf = nullBuffer - } else if b[n-1] != 0 { - // Append NULL to buffer, but try to avoid reallocation - if cap(b) > n { - // Overwrite next byte but restore when done - b = b[:n+1] - c := b[n] - b[n] = 0 - - z.buf = b - z.restore = func() { - b[n] = c - } - } else { - z.buf = append(b, 0) - } - } - return z -} - -// Restore restores the replaced byte past the end of the buffer by NULL. -func (z *Lexer) Restore() { - if z.restore != nil { - z.restore() - z.restore = nil - } -} - -// Err returns the error returned from io.Reader or io.EOF when the end has been reached. -func (z *Lexer) Err() error { - return z.PeekErr(0) -} - -// PeekErr returns the error at position pos. When pos is zero, this is the same as calling Err(). -func (z *Lexer) PeekErr(pos int) error { - if z.err != nil { - return z.err - } else if z.pos+pos >= len(z.buf)-1 { - return io.EOF - } - return nil -} - -// Peek returns the ith byte relative to the end position. -// Peek returns 0 when an error has occurred, Err returns the error. -func (z *Lexer) Peek(pos int) byte { - pos += z.pos - return z.buf[pos] -} - -// PeekRune returns the rune and rune length of the ith byte relative to the end position. -func (z *Lexer) PeekRune(pos int) (rune, int) { - // from unicode/utf8 - c := z.Peek(pos) - if c < 0xC0 || z.Peek(pos+1) == 0 { - return rune(c), 1 - } else if c < 0xE0 || z.Peek(pos+2) == 0 { - return rune(c&0x1F)<<6 | rune(z.Peek(pos+1)&0x3F), 2 - } else if c < 0xF0 || z.Peek(pos+3) == 0 { - return rune(c&0x0F)<<12 | rune(z.Peek(pos+1)&0x3F)<<6 | rune(z.Peek(pos+2)&0x3F), 3 - } - return rune(c&0x07)<<18 | rune(z.Peek(pos+1)&0x3F)<<12 | rune(z.Peek(pos+2)&0x3F)<<6 | rune(z.Peek(pos+3)&0x3F), 4 -} - -// Move advances the position. -func (z *Lexer) Move(n int) { - z.pos += n -} - -// Pos returns a mark to which can be rewinded. -func (z *Lexer) Pos() int { - return z.pos - z.start -} - -// Rewind rewinds the position to the given position. -func (z *Lexer) Rewind(pos int) { - z.pos = z.start + pos -} - -// Lexeme returns the bytes of the current selection. -func (z *Lexer) Lexeme() []byte { - return z.buf[z.start:z.pos] -} - -// Skip collapses the position to the end of the selection. -func (z *Lexer) Skip() { - z.start = z.pos -} - -// Shift returns the bytes of the current selection and collapses the position to the end of the selection. -func (z *Lexer) Shift() []byte { - b := z.buf[z.start:z.pos] - z.start = z.pos - return b -} - -// Offset returns the character position in the buffer. -func (z *Lexer) Offset() int { - return z.pos -} - -// Bytes returns the underlying buffer. -func (z *Lexer) Bytes() []byte { - return z.buf -} |