git-bug/vendor/github.com/cpuguy83/go-md2man/md2man/roff.go
2018-07-20 15:46:14 +02:00

286 lines
6.4 KiB
Go

package md2man
import (
"bytes"
"fmt"
"html"
"strings"
"github.com/russross/blackfriday"
)
type roffRenderer struct {
ListCounters []int
}
// RoffRenderer creates a new blackfriday Renderer for generating roff documents
// from markdown
func RoffRenderer(flags int) blackfriday.Renderer {
return &roffRenderer{}
}
func (r *roffRenderer) GetFlags() int {
return 0
}
func (r *roffRenderer) TitleBlock(out *bytes.Buffer, text []byte) {
out.WriteString(".TH ")
splitText := bytes.Split(text, []byte("\n"))
for i, line := range splitText {
line = bytes.TrimPrefix(line, []byte("% "))
if i == 0 {
line = bytes.Replace(line, []byte("("), []byte("\" \""), 1)
line = bytes.Replace(line, []byte(")"), []byte("\" \""), 1)
}
line = append([]byte("\""), line...)
line = append(line, []byte("\" ")...)
out.Write(line)
}
out.WriteString("\n")
// disable hyphenation
out.WriteString(".nh\n")
// disable justification (adjust text to left margin only)
out.WriteString(".ad l\n")
}
func (r *roffRenderer) BlockCode(out *bytes.Buffer, text []byte, lang string) {
out.WriteString("\n.PP\n.RS\n\n.nf\n")
escapeSpecialChars(out, text)
out.WriteString("\n.fi\n.RE\n")
}
func (r *roffRenderer) BlockQuote(out *bytes.Buffer, text []byte) {
out.WriteString("\n.PP\n.RS\n")
out.Write(text)
out.WriteString("\n.RE\n")
}
func (r *roffRenderer) BlockHtml(out *bytes.Buffer, text []byte) { // nolint: golint
out.Write(text)
}
func (r *roffRenderer) Header(out *bytes.Buffer, text func() bool, level int, id string) {
marker := out.Len()
switch {
case marker == 0:
// This is the doc header
out.WriteString(".TH ")
case level == 1:
out.WriteString("\n\n.SH ")
case level == 2:
out.WriteString("\n.SH ")
default:
out.WriteString("\n.SS ")
}
if !text() {
out.Truncate(marker)
return
}
}
func (r *roffRenderer) HRule(out *bytes.Buffer) {
out.WriteString("\n.ti 0\n\\l'\\n(.lu'\n")
}
func (r *roffRenderer) List(out *bytes.Buffer, text func() bool, flags int) {
marker := out.Len()
r.ListCounters = append(r.ListCounters, 1)
out.WriteString("\n.RS\n")
if !text() {
out.Truncate(marker)
return
}
r.ListCounters = r.ListCounters[:len(r.ListCounters)-1]
out.WriteString("\n.RE\n")
}
func (r *roffRenderer) ListItem(out *bytes.Buffer, text []byte, flags int) {
if flags&blackfriday.LIST_TYPE_ORDERED != 0 {
out.WriteString(fmt.Sprintf(".IP \"%3d.\" 5\n", r.ListCounters[len(r.ListCounters)-1]))
r.ListCounters[len(r.ListCounters)-1]++
} else {
out.WriteString(".IP \\(bu 2\n")
}
out.Write(text)
out.WriteString("\n")
}
func (r *roffRenderer) Paragraph(out *bytes.Buffer, text func() bool) {
marker := out.Len()
out.WriteString("\n.PP\n")
if !text() {
out.Truncate(marker)
return
}
if marker != 0 {
out.WriteString("\n")
}
}
func (r *roffRenderer) Table(out *bytes.Buffer, header []byte, body []byte, columnData []int) {
out.WriteString("\n.TS\nallbox;\n")
maxDelims := 0
lines := strings.Split(strings.TrimRight(string(header), "\n")+"\n"+strings.TrimRight(string(body), "\n"), "\n")
for _, w := range lines {
curDelims := strings.Count(w, "\t")
if curDelims > maxDelims {
maxDelims = curDelims
}
}
out.Write([]byte(strings.Repeat("l ", maxDelims+1) + "\n"))
out.Write([]byte(strings.Repeat("l ", maxDelims+1) + ".\n"))
out.Write(header)
if len(header) > 0 {
out.Write([]byte("\n"))
}
out.Write(body)
out.WriteString("\n.TE\n")
}
func (r *roffRenderer) TableRow(out *bytes.Buffer, text []byte) {
if out.Len() > 0 {
out.WriteString("\n")
}
out.Write(text)
}
func (r *roffRenderer) TableHeaderCell(out *bytes.Buffer, text []byte, align int) {
if out.Len() > 0 {
out.WriteString("\t")
}
if len(text) == 0 {
text = []byte{' '}
}
out.Write([]byte("\\fB\\fC" + string(text) + "\\fR"))
}
func (r *roffRenderer) TableCell(out *bytes.Buffer, text []byte, align int) {
if out.Len() > 0 {
out.WriteString("\t")
}
if len(text) > 30 {
text = append([]byte("T{\n"), text...)
text = append(text, []byte("\nT}")...)
}
if len(text) == 0 {
text = []byte{' '}
}
out.Write(text)
}
func (r *roffRenderer) Footnotes(out *bytes.Buffer, text func() bool) {
}
func (r *roffRenderer) FootnoteItem(out *bytes.Buffer, name, text []byte, flags int) {
}
func (r *roffRenderer) AutoLink(out *bytes.Buffer, link []byte, kind int) {
out.WriteString("\n\\[la]")
out.Write(link)
out.WriteString("\\[ra]")
}
func (r *roffRenderer) CodeSpan(out *bytes.Buffer, text []byte) {
out.WriteString("\\fB\\fC")
escapeSpecialChars(out, text)
out.WriteString("\\fR")
}
func (r *roffRenderer) DoubleEmphasis(out *bytes.Buffer, text []byte) {
out.WriteString("\\fB")
out.Write(text)
out.WriteString("\\fP")
}
func (r *roffRenderer) Emphasis(out *bytes.Buffer, text []byte) {
out.WriteString("\\fI")
out.Write(text)
out.WriteString("\\fP")
}
func (r *roffRenderer) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte) {
}
func (r *roffRenderer) LineBreak(out *bytes.Buffer) {
out.WriteString("\n.br\n")
}
func (r *roffRenderer) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) {
out.Write(content)
r.AutoLink(out, link, 0)
}
func (r *roffRenderer) RawHtmlTag(out *bytes.Buffer, tag []byte) { // nolint: golint
out.Write(tag)
}
func (r *roffRenderer) TripleEmphasis(out *bytes.Buffer, text []byte) {
out.WriteString("\\s+2")
out.Write(text)
out.WriteString("\\s-2")
}
func (r *roffRenderer) StrikeThrough(out *bytes.Buffer, text []byte) {
}
func (r *roffRenderer) FootnoteRef(out *bytes.Buffer, ref []byte, id int) {
}
func (r *roffRenderer) Entity(out *bytes.Buffer, entity []byte) {
out.WriteString(html.UnescapeString(string(entity)))
}
func (r *roffRenderer) NormalText(out *bytes.Buffer, text []byte) {
escapeSpecialChars(out, text)
}
func (r *roffRenderer) DocumentHeader(out *bytes.Buffer) {
}
func (r *roffRenderer) DocumentFooter(out *bytes.Buffer) {
}
func needsBackslash(c byte) bool {
for _, r := range []byte("-_&\\~") {
if c == r {
return true
}
}
return false
}
func escapeSpecialChars(out *bytes.Buffer, text []byte) {
for i := 0; i < len(text); i++ {
// escape initial apostrophe or period
if len(text) >= 1 && (text[0] == '\'' || text[0] == '.') {
out.WriteString("\\&")
}
// directly copy normal characters
org := i
for i < len(text) && !needsBackslash(text[i]) {
i++
}
if i > org {
out.Write(text[org:i])
}
// escape a character
if i >= len(text) {
break
}
out.WriteByte('\\')
out.WriteByte(text[i])
}
}