Forbid -d when digit map cannot be shown

-d shows only the digit map and nothing else, so if the digit map cannot
be shown (e.g. radices above 36 without -f), it makes sense to forbid
this rather than print an empty string.

2 files changed, 3 insertions, 3 deletions

diff --git a/args.go b/args.go
index fbb4cf0..0fb12d4 100644
--- a/args.go
+++ b/args.go
@@ -61,6 +61,8 @@ func parseArgs() (args, error) {
 		return args{}, uintParsingError(flag.Arg(0), err)
 	} else if radix < 2 {
 		return args{}, errors.New("Cannot use 0 or 1 as radices.")
+	} else if radix > maxSmallRadix && a.DigitMapOnly && !a.FullMap {
+		return args{}, errors.New("Used -d option, but digit map cannot be shown.")
 	}
 
 	a.Radix = uint(radix)
diff --git a/print_digit_map.go b/print_digit_map.go
index 1f5ad64..3e59c8c 100644
--- a/print_digit_map.go
+++ b/print_digit_map.go
@@ -12,9 +12,7 @@ import (
 const maxSmallRadix = 36
 
 func writeDigitMap(w io.Writer, digitMap []factors.DigitType) {
-	if len(digitMap) < 2 {
-		panic("Radices cannot be less than 2!")
-	} else if len(digitMap) <= 36 {
+	if len(digitMap) <= 36 {
 		writeDigitMapSmall(w, digitMap)
 	}
 }