// // Blackfriday Markdown Processor // Available at http://github.com/russross/blackfriday // // Copyright © 2011 Russ Ross <russ@russross.com>. // Distributed under the Simplified BSD License. // See README.md for details. // // // // LaTeX rendering backend // // package blackfriday import ( "bytes" "strings" ) // Latex is a type that implements the Renderer interface for LaTeX output. // // Do not create this directly, instead use the LatexRenderer function. type Latex struct { } // LatexRenderer creates and configures a Latex object, which // satisfies the Renderer interface. // // flags is a set of LATEX_* options ORed together (currently no such options // are defined). func LatexRenderer(flags int) Renderer { return &Latex{} } func (options *Latex) GetFlags() int { return 0 } // render code chunks using verbatim, or listings if we have a language func (options *Latex) BlockCode(out *bytes.Buffer, text []byte, info string) { if info == "" { out.WriteString("\n\\begin{verbatim}\n") } else { lang := strings.Fields(info)[0] out.WriteString("\n\\begin{lstlisting}[language=") out.WriteString(lang) out.WriteString("]\n") } out.Write(text) if info == "" { out.WriteString("\n\\end{verbatim}\n") } else { out.WriteString("\n\\end{lstlisting}\n") } } func (options *Latex) TitleBlock(out *bytes.Buffer, text []byte) { } func (options *Latex) BlockQuote(out *bytes.Buffer, text []byte) { out.WriteString("\n\\begin{quotation}\n") out.Write(text) out.WriteString("\n\\end{quotation}\n") } func (options *Latex) BlockHtml(out *bytes.Buffer, text []byte) { // a pretty lame thing to do... out.WriteString("\n\\begin{verbatim}\n") out.Write(text) out.WriteString("\n\\end{verbatim}\n") } func (options *Latex) Header(out *bytes.Buffer, text func() bool, level int, id string) { marker := out.Len() switch level { case 1: out.WriteString("\n\\section{") case 2: out.WriteString("\n\\subsection{") case 3: out.WriteString("\n\\subsubsection{") case 4: out.WriteString("\n\\paragraph{") case 5: out.WriteString("\n\\subparagraph{") case 6: out.WriteString("\n\\textbf{") } if !text() { out.Truncate(marker) return } out.WriteString("}\n") } func (options *Latex) HRule(out *bytes.Buffer) { out.WriteString("\n\\HRule\n") } func (options *Latex) List(out *bytes.Buffer, text func() bool, flags int) { marker := out.Len() if flags&LIST_TYPE_ORDERED != 0 { out.WriteString("\n\\begin{enumerate}\n") } else { out.WriteString("\n\\begin{itemize}\n") } if !text() { out.Truncate(marker) return } if flags&LIST_TYPE_ORDERED != 0 { out.WriteString("\n\\end{enumerate}\n") } else { out.WriteString("\n\\end{itemize}\n") } } func (options *Latex) ListItem(out *bytes.Buffer, text []byte, flags int) { out.WriteString("\n\\item ") out.Write(text) } func (options *Latex) Paragraph(out *bytes.Buffer, text func() bool) { marker := out.Len() out.WriteString("\n") if !text() { out.Truncate(marker) return } out.WriteString("\n") } func (options *Latex) Table(out *bytes.Buffer, header []byte, body []byte, columnData []int) { out.WriteString("\n\\begin{tabular}{") for _, elt := range columnData { switch elt { case TABLE_ALIGNMENT_LEFT: out.WriteByte('l') case TABLE_ALIGNMENT_RIGHT: out.WriteByte('r') default: out.WriteByte('c') } } out.WriteString("}\n") out.Write(header) out.WriteString(" \\\\\n\\hline\n") out.Write(body) out.WriteString("\n\\end{tabular}\n") } func (options *Latex) TableRow(out *bytes.Buffer, text []byte) { if out.Len() > 0 { out.WriteString(" \\\\\n") } out.Write(text) } func (options *Latex) TableHeaderCell(out *bytes.Buffer, text []byte, align int) { if out.Len() > 0 { out.WriteString(" & ") } out.Write(text) } func (options *Latex) TableCell(out *bytes.Buffer, text []byte, align int) { if out.Len() > 0 { out.WriteString(" & ") } out.Write(text) } // TODO: this func (options *Latex) Footnotes(out *bytes.Buffer, text func() bool) { } func (options *Latex) FootnoteItem(out *bytes.Buffer, name, text []byte, flags int) { } func (options *Latex) AutoLink(out *bytes.Buffer, link []byte, kind int) { out.WriteString("\\href{") if kind == LINK_TYPE_EMAIL { out.WriteString("mailto:") } out.Write(link) out.WriteString("}{") out.Write(link) out.WriteString("}") } func (options *Latex) CodeSpan(out *bytes.Buffer, text []byte) { out.WriteString("\\texttt{") escapeSpecialChars(out, text) out.WriteString("}") } func (options *Latex) DoubleEmphasis(out *bytes.Buffer, text []byte) { out.WriteString("\\textbf{") out.Write(text) out.WriteString("}") } func (options *Latex) Emphasis(out *bytes.Buffer, text []byte) { out.WriteString("\\textit{") out.Write(text) out.WriteString("}") } func (options *Latex) Image(out *bytes.Buffer, link []byte, title []byte, alt []byte) { if bytes.HasPrefix(link, []byte("http://")) || bytes.HasPrefix(link, []byte("https://")) { // treat it like a link out.WriteString("\\href{") out.Write(link) out.WriteString("}{") out.Write(alt) out.WriteString("}") } else { out.WriteString("\\includegraphics{") out.Write(link) out.WriteString("}") } } func (options *Latex) LineBreak(out *bytes.Buffer) { out.WriteString(" \\\\\n") } func (options *Latex) Link(out *bytes.Buffer, link []byte, title []byte, content []byte) { out.WriteString("\\href{") out.Write(link) out.WriteString("}{") out.Write(content) out.WriteString("}") } func (options *Latex) RawHtmlTag(out *bytes.Buffer, tag []byte) { } func (options *Latex) TripleEmphasis(out *bytes.Buffer, text []byte) { out.WriteString("\\textbf{\\textit{") out.Write(text) out.WriteString("}}") } func (options *Latex) StrikeThrough(out *bytes.Buffer, text []byte) { out.WriteString("\\sout{") out.Write(text) out.WriteString("}") } // TODO: this func (options *Latex) FootnoteRef(out *bytes.Buffer, ref []byte, id int) { } 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++ { // 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]) } } func (options *Latex) Entity(out *bytes.Buffer, entity []byte) { // TODO: convert this into a unicode character or something out.Write(entity) } func (options *Latex) NormalText(out *bytes.Buffer, text []byte) { escapeSpecialChars(out, text) } // header and footer func (options *Latex) DocumentHeader(out *bytes.Buffer) { out.WriteString("\\documentclass{article}\n") out.WriteString("\n") out.WriteString("\\usepackage{graphicx}\n") out.WriteString("\\usepackage{listings}\n") out.WriteString("\\usepackage[margin=1in]{geometry}\n") out.WriteString("\\usepackage[utf8]{inputenc}\n") out.WriteString("\\usepackage{verbatim}\n") out.WriteString("\\usepackage[normalem]{ulem}\n") out.WriteString("\\usepackage{hyperref}\n") out.WriteString("\n") out.WriteString("\\hypersetup{colorlinks,%\n") out.WriteString(" citecolor=black,%\n") out.WriteString(" filecolor=black,%\n") out.WriteString(" linkcolor=black,%\n") out.WriteString(" urlcolor=black,%\n") out.WriteString(" pdfstartview=FitH,%\n") out.WriteString(" breaklinks=true,%\n") out.WriteString(" pdfauthor={Blackfriday Markdown Processor v") out.WriteString(VERSION) out.WriteString("}}\n") out.WriteString("\n") out.WriteString("\\newcommand{\\HRule}{\\rule{\\linewidth}{0.5mm}}\n") out.WriteString("\\addtolength{\\parskip}{0.5\\baselineskip}\n") out.WriteString("\\parindent=0pt\n") out.WriteString("\n") out.WriteString("\\begin{document}\n") } func (options *Latex) DocumentFooter(out *bytes.Buffer) { out.WriteString("\n\\end{document}\n") }