You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
74 lines
1.5 KiB
74 lines
1.5 KiB
package text
|
|
|
|
import (
|
|
"io"
|
|
)
|
|
|
|
// Indent inserts prefix at the beginning of each non-empty line of s. The
|
|
// end-of-line marker is NL.
|
|
func Indent(s, prefix string) string {
|
|
return string(IndentBytes([]byte(s), []byte(prefix)))
|
|
}
|
|
|
|
// IndentBytes inserts prefix at the beginning of each non-empty line of b.
|
|
// The end-of-line marker is NL.
|
|
func IndentBytes(b, prefix []byte) []byte {
|
|
var res []byte
|
|
bol := true
|
|
for _, c := range b {
|
|
if bol && c != '\n' {
|
|
res = append(res, prefix...)
|
|
}
|
|
res = append(res, c)
|
|
bol = c == '\n'
|
|
}
|
|
return res
|
|
}
|
|
|
|
// Writer indents each line of its input.
|
|
type indentWriter struct {
|
|
w io.Writer
|
|
bol bool
|
|
pre [][]byte
|
|
sel int
|
|
off int
|
|
}
|
|
|
|
// NewIndentWriter makes a new write filter that indents the input
|
|
// lines. Each line is prefixed in order with the corresponding
|
|
// element of pre. If there are more lines than elements, the last
|
|
// element of pre is repeated for each subsequent line.
|
|
func NewIndentWriter(w io.Writer, pre ...[]byte) io.Writer {
|
|
return &indentWriter{
|
|
w: w,
|
|
pre: pre,
|
|
bol: true,
|
|
}
|
|
}
|
|
|
|
// The only errors returned are from the underlying indentWriter.
|
|
func (w *indentWriter) Write(p []byte) (n int, err error) {
|
|
for _, c := range p {
|
|
if w.bol {
|
|
var i int
|
|
i, err = w.w.Write(w.pre[w.sel][w.off:])
|
|
w.off += i
|
|
if err != nil {
|
|
return n, err
|
|
}
|
|
}
|
|
_, err = w.w.Write([]byte{c})
|
|
if err != nil {
|
|
return n, err
|
|
}
|
|
n++
|
|
w.bol = c == '\n'
|
|
if w.bol {
|
|
w.off = 0
|
|
if w.sel < len(w.pre)-1 {
|
|
w.sel++
|
|
}
|
|
}
|
|
}
|
|
return n, nil
|
|
}
|
|
|