Add ReadRomFile

This function combines ReadRomBlocks() and RomFromBlocks() into a single
function.  The other two functions still exist.

cmd/fdslist.go

@@ -32,18 +32,7 @@ func main() {
 }
 
 func run(args *Arguments) error {
-	file, err := os.Open(args.Input)
-	if err != nil {
-		return err
-	}
-	defer file.Close()
-
-	blocks, err := fds.ReadRom(file, filepath.Ext(args.Input) == ".fds")
-	if err != nil {
-		return err
-	}
-
-	rom, err := fds.RomFromBlocks(filepath.Base(args.Input), blocks)
+	rom, err := fds.ReadRomFile(args.Input, filepath.Ext(args.Input) == ".fds")
 	if err != nil {
 		return err
 	}

reader.go

@@ -1,7 +1,7 @@
 package fds
 
 import (
-	//"os"
+	"os"
 	"fmt"
 	"io"
 	"bufio"
@@ -11,7 +11,22 @@ import (
 	"github.com/sigurn/crc16"
 )
 
-func ReadRom(r io.Reader, IsFds bool) ([]DiskBlock, error) {
+func ReadRomFile(filename string, IsFds bool) (*Rom, error) {
+	file, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	blocks, err := ReadRomBlocks(file, IsFds)
+	if err != nil {
+		return nil, err
+	}
+
+	return RomFromBlocks(filename, blocks)
+}
+
+func ReadRomBlocks(r io.Reader, IsFds bool) ([]DiskBlock, error) {
 	reader := bufio.NewReader(r)
 	magic, err := reader.Peek(4)
 	if err != nil {