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

4 files changed, 20 insertions, 1 deletions

diff --git a/README.md b/README.md
index 157165d..cb7d9a5 100644
--- a/README.md
+++ b/README.md
@@ -99,6 +99,10 @@ perc calc x 5 = x x +     # x + x = 10
 
 perc calc pi 3.14159 = pi 2 *  # 2 * π
 # → 6.28318
+
+# Note: Variable assignment only works with calc/rpn subcommand:
+# perc calc x 5 = x x +  (works)
+# perc x 5 =             (won't work in bare mode - use "perc calc x 5 =")
 ```
 
 #### Variable Management
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
diff --git a/internal/repl/repl.go b/internal/repl/repl.go
index 79a94f4..ed39755 100644
--- a/internal/repl/repl.go
+++ b/internal/repl/repl.go
@@ -51,7 +51,15 @@ func executor(input string) {
 		return
 	}
 
-	// Run the calculation
+	// Try RPN parsing first (for bare RPN expressions like "3 4 +")
+	rpnResult, rpnErr := runRPN(input)
+	if rpnErr == nil {
+		// Valid RPN expression - print result
+		fmt.Println(rpnResult)
+		return
+	}
+
+	// Run the percentage calculation
 	result, err := calculator.Parse(input)
 	if err != nil {
 		fmt.Printf("Error: %v\n", err)
diff --git a/perc_local b/perc_local
new file mode 100755
index 0000000..99ffa8e
--- /dev/null
+++ b/perc_local