diff -r 4f153a23adab -r 6d9efbef00a9 vendor/github.com/cpuguy83/go-md2man/v2/md2man/roff.go --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/vendor/github.com/cpuguy83/go-md2man/v2/md2man/roff.go Sun Jul 11 10:35:56 2021 +0200 @@ -0,0 +1,345 @@ +package md2man + +import ( + "fmt" + "io" + "os" + "strings" + + "github.com/russross/blackfriday/v2" +) + +// roffRenderer implements the blackfriday.Renderer interface for creating +// roff format (manpages) from markdown text +type roffRenderer struct { + extensions blackfriday.Extensions + listCounters []int + firstHeader bool + defineTerm bool + listDepth int +} + +const ( + titleHeader = ".TH " + topLevelHeader = "\n\n.SH " + secondLevelHdr = "\n.SH " + otherHeader = "\n.SS " + crTag = "\n" + emphTag = "\\fI" + emphCloseTag = "\\fP" + strongTag = "\\fB" + strongCloseTag = "\\fP" + breakTag = "\n.br\n" + paraTag = "\n.PP\n" + hruleTag = "\n.ti 0\n\\l'\\n(.lu'\n" + linkTag = "\n\\[la]" + linkCloseTag = "\\[ra]" + codespanTag = "\\fB\\fC" + codespanCloseTag = "\\fR" + codeTag = "\n.PP\n.RS\n\n.nf\n" + codeCloseTag = "\n.fi\n.RE\n" + quoteTag = "\n.PP\n.RS\n" + quoteCloseTag = "\n.RE\n" + listTag = "\n.RS\n" + listCloseTag = "\n.RE\n" + arglistTag = "\n.TP\n" + tableStart = "\n.TS\nallbox;\n" + tableEnd = ".TE\n" + tableCellStart = "T{\n" + tableCellEnd = "\nT}\n" +) + +// NewRoffRenderer creates a new blackfriday Renderer for generating roff documents +// from markdown +func NewRoffRenderer() *roffRenderer { // nolint: golint + var extensions blackfriday.Extensions + + extensions |= blackfriday.NoIntraEmphasis + extensions |= blackfriday.Tables + extensions |= blackfriday.FencedCode + extensions |= blackfriday.SpaceHeadings + extensions |= blackfriday.Footnotes + extensions |= blackfriday.Titleblock + extensions |= blackfriday.DefinitionLists + return &roffRenderer{ + extensions: extensions, + } +} + +// GetExtensions returns the list of extensions used by this renderer implementation +func (r *roffRenderer) GetExtensions() blackfriday.Extensions { + return r.extensions +} + +// RenderHeader handles outputting the header at document start +func (r *roffRenderer) RenderHeader(w io.Writer, ast *blackfriday.Node) { + // disable hyphenation + out(w, ".nh\n") +} + +// RenderFooter handles outputting the footer at the document end; the roff +// renderer has no footer information +func (r *roffRenderer) RenderFooter(w io.Writer, ast *blackfriday.Node) { +} + +// RenderNode is called for each node in a markdown document; based on the node +// type the equivalent roff output is sent to the writer +func (r *roffRenderer) RenderNode(w io.Writer, node *blackfriday.Node, entering bool) blackfriday.WalkStatus { + + var walkAction = blackfriday.GoToNext + + switch node.Type { + case blackfriday.Text: + r.handleText(w, node, entering) + case blackfriday.Softbreak: + out(w, crTag) + case blackfriday.Hardbreak: + out(w, breakTag) + case blackfriday.Emph: + if entering { + out(w, emphTag) + } else { + out(w, emphCloseTag) + } + case blackfriday.Strong: + if entering { + out(w, strongTag) + } else { + out(w, strongCloseTag) + } + case blackfriday.Link: + if !entering { + out(w, linkTag+string(node.LinkData.Destination)+linkCloseTag) + } + case blackfriday.Image: + // ignore images + walkAction = blackfriday.SkipChildren + case blackfriday.Code: + out(w, codespanTag) + escapeSpecialChars(w, node.Literal) + out(w, codespanCloseTag) + case blackfriday.Document: + break + case blackfriday.Paragraph: + // roff .PP markers break lists + if r.listDepth > 0 { + return blackfriday.GoToNext + } + if entering { + out(w, paraTag) + } else { + out(w, crTag) + } + case blackfriday.BlockQuote: + if entering { + out(w, quoteTag) + } else { + out(w, quoteCloseTag) + } + case blackfriday.Heading: + r.handleHeading(w, node, entering) + case blackfriday.HorizontalRule: + out(w, hruleTag) + case blackfriday.List: + r.handleList(w, node, entering) + case blackfriday.Item: + r.handleItem(w, node, entering) + case blackfriday.CodeBlock: + out(w, codeTag) + escapeSpecialChars(w, node.Literal) + out(w, codeCloseTag) + case blackfriday.Table: + r.handleTable(w, node, entering) + case blackfriday.TableCell: + r.handleTableCell(w, node, entering) + case blackfriday.TableHead: + case blackfriday.TableBody: + case blackfriday.TableRow: + // no action as cell entries do all the nroff formatting + return blackfriday.GoToNext + default: + fmt.Fprintln(os.Stderr, "WARNING: go-md2man does not handle node type "+node.Type.String()) + } + return walkAction +} + +func (r *roffRenderer) handleText(w io.Writer, node *blackfriday.Node, entering bool) { + var ( + start, end string + ) + // handle special roff table cell text encapsulation + if node.Parent.Type == blackfriday.TableCell { + if len(node.Literal) > 30 { + start = tableCellStart + end = tableCellEnd + } else { + // end rows that aren't terminated by "tableCellEnd" with a cr if end of row + if node.Parent.Next == nil && !node.Parent.IsHeader { + end = crTag + } + } + } + out(w, start) + escapeSpecialChars(w, node.Literal) + out(w, end) +} + +func (r *roffRenderer) handleHeading(w io.Writer, node *blackfriday.Node, entering bool) { + if entering { + switch node.Level { + case 1: + if !r.firstHeader { + out(w, titleHeader) + r.firstHeader = true + break + } + out(w, topLevelHeader) + case 2: + out(w, secondLevelHdr) + default: + out(w, otherHeader) + } + } +} + +func (r *roffRenderer) handleList(w io.Writer, node *blackfriday.Node, entering bool) { + openTag := listTag + closeTag := listCloseTag + if node.ListFlags&blackfriday.ListTypeDefinition != 0 { + // tags for definition lists handled within Item node + openTag = "" + closeTag = "" + } + if entering { + r.listDepth++ + if node.ListFlags&blackfriday.ListTypeOrdered != 0 { + r.listCounters = append(r.listCounters, 1) + } + out(w, openTag) + } else { + if node.ListFlags&blackfriday.ListTypeOrdered != 0 { + r.listCounters = r.listCounters[:len(r.listCounters)-1] + } + out(w, closeTag) + r.listDepth-- + } +} + +func (r *roffRenderer) handleItem(w io.Writer, node *blackfriday.Node, entering bool) { + if entering { + if node.ListFlags&blackfriday.ListTypeOrdered != 0 { + out(w, fmt.Sprintf(".IP \"%3d.\" 5\n", r.listCounters[len(r.listCounters)-1])) + r.listCounters[len(r.listCounters)-1]++ + } else if node.ListFlags&blackfriday.ListTypeDefinition != 0 { + // state machine for handling terms and following definitions + // since blackfriday does not distinguish them properly, nor + // does it seperate them into separate lists as it should + if !r.defineTerm { + out(w, arglistTag) + r.defineTerm = true + } else { + r.defineTerm = false + } + } else { + out(w, ".IP \\(bu 2\n") + } + } else { + out(w, "\n") + } +} + +func (r *roffRenderer) handleTable(w io.Writer, node *blackfriday.Node, entering bool) { + if entering { + out(w, tableStart) + //call walker to count cells (and rows?) so format section can be produced + columns := countColumns(node) + out(w, strings.Repeat("l ", columns)+"\n") + out(w, strings.Repeat("l ", columns)+".\n") + } else { + out(w, tableEnd) + } +} + +func (r *roffRenderer) handleTableCell(w io.Writer, node *blackfriday.Node, entering bool) { + var ( + start, end string + ) + if node.IsHeader { + start = codespanTag + end = codespanCloseTag + } + if entering { + if node.Prev != nil && node.Prev.Type == blackfriday.TableCell { + out(w, "\t"+start) + } else { + out(w, start) + } + } else { + // need to carriage return if we are at the end of the header row + if node.IsHeader && node.Next == nil { + end = end + crTag + } + out(w, end) + } +} + +// because roff format requires knowing the column count before outputting any table +// data we need to walk a table tree and count the columns +func countColumns(node *blackfriday.Node) int { + var columns int + + node.Walk(func(node *blackfriday.Node, entering bool) blackfriday.WalkStatus { + switch node.Type { + case blackfriday.TableRow: + if !entering { + return blackfriday.Terminate + } + case blackfriday.TableCell: + if entering { + columns++ + } + default: + } + return blackfriday.GoToNext + }) + return columns +} + +func out(w io.Writer, output string) { + io.WriteString(w, output) // nolint: errcheck +} + +func needsBackslash(c byte) bool { + for _, r := range []byte("-_&\\~") { + if c == r { + return true + } + } + return false +} + +func escapeSpecialChars(w io.Writer, text []byte) { + for i := 0; i < len(text); i++ { + // escape initial apostrophe or period + if len(text) >= 1 && (text[0] == '\'' || text[0] == '.') { + out(w, "\\&") + } + + // directly copy normal characters + org := i + + for i < len(text) && !needsBackslash(text[i]) { + i++ + } + if i > org { + w.Write(text[org:i]) // nolint: errcheck + } + + // escape a character + if i >= len(text) { + break + } + + w.Write([]byte{'\\', text[i]}) // nolint: errcheck + } +}