cmd/perc/main.go: try RPN parsing before percentage calculation in command mode

- Bare expressions like '1 2 +' now work without 'calc' prefix
- Assignment format 'name value =' requires 'calc' subcommand prefix

1 files changed, 7 insertions, 0 deletions

diff --git a/cmd/perc/main.go b/cmd/perc/main.go
index d33593c..2cee268 100644
--- a/cmd/perc/main.go
+++ b/cmd/perc/main.go
@@ -56,6 +56,13 @@ func runCommand(args []string) (string, error) {
 	}
 
 	input := strings.Join(args[1:], " ")
+	
+	// Try RPN parsing first (for bare RPN expressions like "3 4 +")
+	if rpnResult, rpnErr := runRPN(input); rpnErr == nil {
+		return rpnResult, nil
+	}
+	
+	// Fall back to percentage calculation
 	result, err := calculator.Parse(input)
 	if err != nil {
 		return "", err