Added virtual symbol SymVariable translated from general real SymIdentifier symbol

operand-var.go

@@ -8,7 +8,7 @@ import "fmt"
 
 // -------- variable term
 func newVarTerm(tk *Token) *term {
-	return &term{
+	t := &term{
 		tk: *tk,
 		// class:    classVar,
 		// kind:     kindUnknown,
@@ -18,6 +18,8 @@ func newVarTerm(tk *Token) *term {
 		priority: priValue,
 		evalFunc: evalVar,
 	}
+	t.tk.Sym = SymVariable
+	return t
 }
 
 // -------- eval func