fix(rpn): consolidate extractVarName into rpn_parse.go (task 6k)

2 files changed, 13 insertions, 14 deletions

diff --git a/internal/rpn/operations_variables.go b/internal/rpn/operations_variables.go
index 9f60133..d1b07eb 100644
--- a/internal/rpn/operations_variables.go
+++ b/internal/rpn/operations_variables.go
@@ -97,20 +97,6 @@ func (o *Operations) ClearVariables() {
 	o.vars.ClearVariables()
 }
 
-// extractVarName extracts a variable name from a StackValue.
-// Symbols use their internal name, StringNums use their string value,
-// and all other types fall back to String().
-func extractVarName(val StackValue) string {
-	switch v := val.(type) {
-	case *Symbol:
-		return v.Name()
-	case *StringNum:
-		return v.String()
-	default:
-		return val.String()
-	}
-}
-
 // AssignLeft assigns a value to a variable (for =: operator).
 // Stack order: value name =: (value on bottom, name on top).
 // This function pops name first (top of stack), then value.
diff --git a/internal/rpn/rpn_parse.go b/internal/rpn/rpn_parse.go
index 92292ae..51c64c7 100644
--- a/internal/rpn/rpn_parse.go
+++ b/internal/rpn/rpn_parse.go
@@ -405,6 +405,19 @@ func extractVariableName(token string) string {
 	return token
 }
 
+// extractVarName extracts a variable name from a StackValue.
+// Handles Symbol and StringNum types, falls back to String().
+func extractVarName(val StackValue) string {
+	switch v := val.(type) {
+	case *Symbol:
+		return v.Name()
+	case *StringNum:
+		return v.String()
+	default:
+		return val.String()
+	}
+}
+
 // checkStackOverflow returns an error if the stack has reached the maximum size.
 func (r *RPN) checkStackOverflow(stack *Stack) error {
 	if stack.Len() >= r.maxStack {