fork of go-gitdiff with jj support
oppi.li
1package gitdiff
2
3import (
4 "bufio"
5 "io"
6)
7
8// StringReader is the interface that wraps the ReadString method.
9type StringReader interface {
10 // ReadString reads until the first occurrence of delim in the input,
11 // returning a string containing the data up to and including the
12 // delimiter. If ReadString encounters an error before finding a delimiter,
13 // it returns the data read before the error and the error itself (often
14 // io.EOF). ReadString returns err != nil if and only if the returned data
15 // does not end in delim.
16 ReadString(delim byte) (string, error)
17}
18
19// LineReader is the interface that wraps the ReadLine method.
20type LineReader interface {
21 // ReadLine reads the next full line in the input, returing the the data
22 // including the line ending character(s) and the zero-indexed line number.
23 // If ReadLine encounters an error before reaching the end of the line, it
24 // returns the data read before the error and the error itself (often
25 // io.EOF). ReadLine returns err != nil if and only if the returned data is
26 // not a complete line.
27 //
28 // If the implementation defines other methods for reading the same input,
29 // line numbers may be incorrect if calls to ReadLine are mixed with calls
30 // to other read methods.
31 ReadLine() (string, int, error)
32}
33
34// NewLineReader returns a LineReader for a reader starting at a specific line
35// using the newline character, \n, as a line separator. If r is a
36// StringReader, it is used directly. Otherwise, it is wrapped in a way that
37// may read extra data from the underlying input.
38func NewLineReader(r io.Reader, lineno int) LineReader {
39 sr, ok := r.(StringReader)
40 if !ok {
41 sr = bufio.NewReader(r)
42 }
43 return &lineReader{r: sr, n: lineno}
44}
45
46type lineReader struct {
47 r StringReader
48 n int
49}
50
51func (lr *lineReader) ReadLine() (line string, lineno int, err error) {
52 lineno = lr.n
53 line, err = lr.r.ReadString('\n')
54 if err == nil {
55 lr.n++
56 }
57 return
58}