Add first pass of integer basic decoding

It doesn't do proper spacing yet - the intbasic code listing is
extremely tricky to undestand.

cmd/decode.go

@@ -7,7 +7,8 @@ import (
 	"os"
 
 	"github.com/spf13/cobra"
-	"github.com/zellyn/diskii/lib/applesoft"
+	"github.com/zellyn/diskii/lib/basic"
+	"github.com/zellyn/diskii/lib/basic/applesoft"
 	"github.com/zellyn/diskii/lib/helpers"
 )
 
@@ -61,7 +62,7 @@ func runDecode(args []string) error {
 	if rawControlCodes {
 		os.Stdout.WriteString(listing.String())
 	} else {
-		os.Stdout.WriteString(applesoft.ChevronControlCodes(listing.String()))
+		os.Stdout.WriteString(basic.ChevronControlCodes(listing.String()))
 	}
 	return nil
 }

lib/applesoft/applesoft.go → lib/basic/applesoft/applesoft.go

@@ -7,7 +7,6 @@ package applesoft
 import (
 	"bytes"
 	"fmt"
-	"regexp"
 )
 
 // TokensByCode is a map from byte value to token text.
@@ -215,33 +214,3 @@ func (l Listing) String() string {
 	}
 	return buf.String()
 }
-
-var controlCharRegexp = regexp.MustCompile(`[\x00-\x1F]`)
-
-// ChevronControlCodes converts ASCII control characters like chr(4)
-// to chevron-surrounded codes like «ctrl-D».
-func ChevronControlCodes(s string) string {
-	return controlCharRegexp.ReplaceAllStringFunc(s, func(s string) string {
-		if s == "\n" || s == "\t" {
-			return s
-		}
-		if s >= "\x01" && s <= "\x1a" {
-			return "«ctrl-" + string('A'-1+s[0]) + "»"
-		}
-		code := "?"
-		switch s[0] {
-		case '\x00':
-			code = "NUL"
-		case '\x1C':
-			code = "FS"
-		case '\x1D':
-			code = "GS"
-		case '\x1E':
-			code = "RS"
-		case '\x1F':
-			code = "US"
-		}
-
-		return "«" + code + "»"
-	})
-}

lib/applesoft/hello_test.go → lib/basic/applesoft/applesoft_test.go

@@ -2,7 +2,11 @@
 
 package applesoft
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/zellyn/diskii/lib/basic"
+)
 
 // helloBinary is a simple basic program used for testing. Listing
 // below.
@@ -46,7 +50,7 @@ func TestParse(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	text := ChevronControlCodes(listing.String())
+	text := basic.ChevronControlCodes(listing.String())
 	if text != helloListing {
 		t.Fatalf("Wrong listing; want:\n%s\ngot:\n%s", helloListing, text)
 	}

lib/basic/basic.go

@@ -0,0 +1,35 @@
+// Package basic contains routines useful for both Applesoft and
+// Integer BASIC.
+package basic
+
+import "regexp"
+
+var controlCharRegexp = regexp.MustCompile(`[\x00-\x1F]`)
+
+// ChevronControlCodes converts ASCII control characters like chr(4)
+// to chevron-surrounded codes like «ctrl-D».
+func ChevronControlCodes(s string) string {
+	return controlCharRegexp.ReplaceAllStringFunc(s, func(s string) string {
+		if s == "\n" || s == "\t" {
+			return s
+		}
+		if s >= "\x01" && s <= "\x1a" {
+			return "«ctrl-" + string('A'-1+s[0]) + "»"
+		}
+		code := "?"
+		switch s[0] {
+		case '\x00':
+			code = "NUL"
+		case '\x1C':
+			code = "FS"
+		case '\x1D':
+			code = "GS"
+		case '\x1E':
+			code = "RS"
+		case '\x1F':
+			code = "US"
+		}
+
+		return "«" + code + "»"
+	})
+}