ics - folder.go

     1  package ics
     2  
     3  import (
     4  	"io"
     5  	"unicode/utf8"
     6  )
     7  
     8  type folder struct {
     9  	w    io.Writer
    10  	err  error
    11  	line uint8
    12  }
    13  
    14  const maxLineLength = 75
    15  
    16  var eol = [...]byte{'\r', '\n', ' '}
    17  
    18  func (f *folder) Write(q []byte) (int, error) {
    19  	if f.err != nil {
    20  		return 0, f.err
    21  	}
    22  	var (
    23  		r       rune
    24  		s, n, m int
    25  	)
    26  	for pos := 0; pos < len(q); pos += s {
    27  		r, s = utf8.DecodeRune(q[pos:])
    28  		f.line += uint8(s)
    29  		if r == '\n' {
    30  			f.line = 0
    31  		} else if r == '\r' {
    32  		} else if f.line > maxLineLength {
    33  			if pos > 0 {
    34  				m, f.err = f.w.Write(q[:pos])
    35  				n += m
    36  				if f.err != nil {
    37  					return n, f.err
    38  				}
    39  				q = q[pos:]
    40  			}
    41  			_, f.err = f.w.Write(eol[:])
    42  			if f.err != nil {
    43  				return n, f.err
    44  			}
    45  
    46  			pos = 0
    47  			f.line = uint8(s) + 1
    48  		}
    49  	}
    50  	if len(q) > 0 {
    51  		m, f.err = f.w.Write(q)
    52  		n += m
    53  	}
    54  	return n, f.err
    55  }
    56  
    57  func (f *folder) WriteString(q string) (int, error) {
    58  	return f.Write([]byte(q))
    59  }