cmd/elvmdfmt: Split Markdown formatting into own command, supporting -w and -d.

Also change the behavior of the rendering command (elvmd) to still output HTML
when given -trace.

Author: xiaq

.codecov.yml

@@ -20,5 +20,6 @@ ignore:
   - "pkg/getopt/zstring.go"
   - "pkg/md/zstring.go"
   - "pkg/parse/zstring.go"
-  # Exclude the copied rpc package.
+  # Exclude the copied diff and rpc packages.
+  - "pkg/diff"
   - "pkg/rpc"

README.md

@@ -41,9 +41,10 @@ The source for the documentation is in the
 All source files use the BSD 2-clause license (see [LICENSE](LICENSE)), except
 for the following:
 
--   Files in [pkg/rpc](pkg/rpc) are released under the BSD 3-clause license,
-    since they are copied from [Go's source code](https://github.com/golang/go).
-    See [pkg/rpc/LICENSE](pkg/rpc/LICENSE).
+-   Files in [pkg/diff](pkg/diff) and [pkg/rpc](pkg/rpc) are released under the
+    BSD 3-clause license, since they are copied from
+    [Go's source code](https://github.com/golang/go). See
+    [pkg/diff/LICENSE](pkg/diff/LICENSE) and [pkg/rpc/LICENSE](pkg/rpc/LICENSE).
 
 -   Files in [pkg/persistent](pkg/persistent) and its subdirectories are
     released under EPL 1.0, since they are partially derived from

cmd/elvmd/main.go

@@ -4,35 +4,41 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"log"
 	"os"
 
 	"src.elv.sh/pkg/md"
 )
 
+var (
+	trace = flag.Bool("trace", false, "write internal parsing results")
+)
+
 func main() {
-	var (
-		format = flag.Bool("fmt", false, "format Markdown")
-		trace  = flag.Bool("trace", false, "trace internal output by parser")
-	)
 	flag.Parse()
-	if *format && *trace {
-		fmt.Fprintln(os.Stderr, "-fmt and -trace are mutually exclusive")
-		os.Exit(1)
-	}
 
-	text, err := io.ReadAll(os.Stdin)
-	if err != nil {
-		log.Fatal(err)
+	files := flag.Args()
+	if len(files) == 0 {
+		text, err := io.ReadAll(os.Stdin)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "read stdin:", err)
+			os.Exit(2)
+		}
+		render(string(text))
+		return
 	}
-	var codec md.StringerCodec
-	switch {
-	case *format:
-		codec = &md.FmtCodec{}
-	case *trace:
-		codec = &md.TraceCodec{}
-	default:
-		codec = &md.HTMLCodec{}
+	for _, file := range files {
+		text, err := os.ReadFile(file)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "read %s: %v\n", file, err)
+			os.Exit(2)
+		}
+		render(string(text))
+	}
+}
+
+func render(markdown string) {
+	fmt.Print(md.RenderString(markdown, &md.HTMLCodec{}))
+	if *trace {
+		fmt.Print(md.RenderString(markdown, &md.TraceCodec{}))
 	}
-	fmt.Print(md.RenderString(string(text), codec))
 }

cmd/elvmdfmt/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"os"
+
+	"src.elv.sh/pkg/diff"
+	"src.elv.sh/pkg/md"
+)
+
+var (
+	overwrite = flag.Bool("w", false, "write result to source file (requires -fmt)")
+	showDiff  = flag.Bool("d", false, "show diff")
+)
+
+func main() {
+	flag.Parse()
+
+	files := flag.Args()
+	if len(files) == 0 {
+		text, err := io.ReadAll(os.Stdin)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "read stdin:", err)
+			os.Exit(2)
+		}
+		fmt.Print(format(string(text)))
+		return
+	}
+	for _, file := range files {
+		text, err := os.ReadFile(file)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "read %s: %v\n", file, err)
+			os.Exit(2)
+		}
+		result := format(string(text))
+		if *overwrite {
+			err := os.WriteFile(file, []byte(result), 0644)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "write %s: %v\n", file, err)
+				os.Exit(2)
+			}
+		} else if !*showDiff {
+			fmt.Print(result)
+		}
+		if *showDiff {
+			os.Stdout.Write(diff.Diff(file+".orig", text, file, []byte(result)))
+		}
+	}
+}
+
+func format(original string) string {
+	return md.RenderString(original, &md.FmtCodec{})
+}

pkg/diff/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.