Provide a public API

This also introduces a simple program, md2gmn, that is meant for testing
the renderer on Markdown files. Nonetheless, it can be used as
a standalone tool as well.

cmd/gmnhg/main.go

@@ -3,56 +3,6 @@
 // TODO: it is yet to actually do that.
 package main
 
-import (
-	"fmt"
-
-	"git.tdem.in/tdemin/gmnhg/internal/gemini"
-	"github.com/davecgh/go-spew/spew"
-	"github.com/gomarkdown/markdown"
-	"github.com/gomarkdown/markdown/parser"
-)
-
-var text = `
-# Some document
-
-This is some markdown [text](https://tdem.in). This is some more text.
-
-![This is some image](https://tdem.in/favicon.ico)
-
-[This is some full-blown link.](https://tdem.in/nyaa)
-
-This is some more plain text. More of it!
-
-+ Unordered list item
-+ Another list item
-	* Indented list item.
-	* Another one.
-+ Third.
-
-1. Ordered list item.
-2. Another one.
-	* and another inset list.
-	* text.
-3. Yay.
-
-` + "```" + `
-some preformatted text
-another line of preformatted text
-
-more lines of preformatted text
-` + "```" + `
-
-## Subheading 2
-
-More text!
-
-> Some weird blockquote. More text.
-> More quote text.
-`
-
 func main() {
-	ast := markdown.Parse([]byte(text), parser.NewWithExtensions(parser.CommonExtensions))
-	spew.Dump(ast)
-	geminiContent := markdown.Render(ast, gemini.NewRenderer())
-	fmt.Printf("---\noriginal:\n---\n%s---\ngemini:\n---\n%s", text, geminiContent)
+	println("in development")
 }

cmd/md2gmn/main.go

@@ -0,0 +1,35 @@
+// md2gmn converts Markdown text files to text/gemini.
+package main
+
+import (
+	"flag"
+	"io/ioutil"
+	"os"
+
+	gemini "git.tdem.in/tdemin/gmnhg"
+)
+
+func main() {
+	var (
+		input string
+		file  *os.File
+	)
+	flag.StringVar(&input, "f", "", "input file")
+	flag.Parse()
+
+	if input != "" {
+		var err error
+		file, err = os.Open(input)
+		if err != nil {
+			panic(err)
+		}
+	} else {
+		file = os.Stdin
+	}
+	text, err := ioutil.ReadAll(file)
+	if err != nil {
+		panic(err)
+	}
+
+	os.Stdout.Write(gemini.RenderMarkdown(text))
+}

go.mod

@@ -2,7 +2,4 @@ module git.tdem.in/tdemin/gmnhg
 
 go 1.15
 
-require (
-	github.com/davecgh/go-spew v1.1.1
-	github.com/gomarkdown/markdown v0.0.0-20201024011455-45c732cc8a6b
-)
+require github.com/gomarkdown/markdown v0.0.0-20201024011455-45c732cc8a6b

go.sum

@@ -1,5 +1,3 @@
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
-github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gomarkdown/markdown v0.0.0-20201024011455-45c732cc8a6b h1:Om9FdD4lzIJELyJxwr9EWSjaG6GMUNS3iebnhrGevhI=
 github.com/gomarkdown/markdown v0.0.0-20201024011455-45c732cc8a6b/go.mod h1:aii0r/K0ZnHv7G0KF7xy1v0A7s2Ljrb5byB7MO5p6TU=
 golang.org/dl v0.0.0-20190829154251-82a15e2f2ead/go.mod h1:IUMfjQLJQd4UTqG1Z90tenwKoCX93Gn3MAQJMOSBsDQ=

render.go

@@ -0,0 +1,16 @@
+package gemini
+
+import (
+	"git.tdem.in/tdemin/gmnhg/internal/gemini"
+	"github.com/gomarkdown/markdown"
+	"github.com/gomarkdown/markdown/parser"
+)
+
+// RenderMarkdown converts Markdown text to text/gemini using gomarkdown.
+//
+// gomarkdown doesn't return any errors, nor does this function.
+func RenderMarkdown(md []byte) (geminiText []byte) {
+	ast := markdown.Parse(md, parser.NewWithExtensions(parser.CommonExtensions))
+	geminiContent := markdown.Render(ast, gemini.NewRenderer())
+	return geminiContent
+}