add md2latex

README.md

@@ -6,4 +6,7 @@ This renderer seeks to be as extensible as Goldmark itself. Please file an issue
 ## Results
 So far this implementation renders the CommonMark specification with the exception of embedded HTML. It does have some bugs related to undefined ASCII sequences. Any help is appreciated.
 
-![result](https://user-images.githubusercontent.com/26156425/188299284-8dd2fca1-dc50-4574-8128-c78017b42e73.png)
+![result](https://user-images.githubusercontent.com/26156425/188299284-8dd2fca1-dc50-4574-8128-c78017b42e73.png)
+
+## md2latex program
+This command converts a single markdown file to latex and writes to contents to a new .text file or to stdout.

cmd/md2latex/main.go

@@ -0,0 +1,91 @@
+package main
+
+import (
+	"bytes"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+
+	latex "github.com/soypat/goldmark-latex"
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/util"
+)
+
+var (
+	usehtml        bool
+	print          bool
+	unhead         bool
+	outputFilename string
+)
+
+func main() {
+	flag.BoolVar(&usehtml, "html", false, "Output html")
+	flag.BoolVar(&print, "p", false, "Output to stdout")
+	flag.BoolVar(&unhead, "unhead", false, "No heading numbering")
+	flag.StringVar(&outputFilename, "o", "", "Output filename. By default just adds .tex to input filename.")
+	flag.Parse()
+	args := flag.Args()
+	err := run(args)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func run(args []string) error {
+	if len(args) == 0 {
+		return errors.New("missing filename argument")
+	}
+	filename := args[0]
+	fp, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	input, err := io.ReadAll(fp)
+	fp.Close()
+	if err != nil {
+		return err
+	}
+	output, err := renderGoldmark(input)
+	if err != nil {
+		return err
+	}
+	if print {
+		fmt.Println(string(output))
+		return nil
+	}
+	// Generate output file.
+	ext := filepath.Ext(filename)
+	if ext == "" && outputFilename == "" {
+		outputFilename = filename + ".tex"
+	} else if outputFilename == "" {
+		outputFilename = strings.TrimSuffix(filename, ext) + ".tex"
+	}
+	outfp, err := os.Create(outputFilename)
+	if err != nil {
+		return err
+	}
+	defer outfp.Close()
+	_, err = io.Copy(outfp, bytes.NewBuffer(output))
+	return err
+}
+
+func renderGoldmark(input []byte) ([]byte, error) {
+	var rd renderer.Renderer
+	if usehtml {
+		rd = goldmark.DefaultRenderer()
+	} else {
+		rd = renderer.NewRenderer(renderer.WithNodeRenderers(util.Prioritized(latex.NewRenderer(latex.Config{
+			NoHeadingNumbering: unhead,
+		}), 1000)))
+	}
+	md := goldmark.New(goldmark.WithRenderer(rd))
+	var b bytes.Buffer
+	err := md.Convert(input, &b)
+	return b.Bytes(), err
+}