Apply suggestions from code review

Lynskylate · youknowone · web-flow · commit 12df480cc9be · 2020-08-01T01:29:11.000+08:00
Co-authored-by: Jeong YunWon &lt;youknowone@users.noreply.github.com&gt;
diff --git a/compiler/src/symboltable.rs b/compiler/src/symboltable.rs
@@ -473,11 +473,12 @@ impl SymbolTableBuilder {
     }
 
     fn scan_parameter(&mut self, parameter: &ast::Parameter) -> SymbolTableResult {
-        if let Some(_annotation) = &parameter.annotation {
-            self.register_name(&parameter.arg, SymbolUsage::AnnotationParameter)
+        let usage = if parameter.annotation.is_some() {
+            SymbolUsage::AnnotationParamater
         } else {
-            self.register_name(&parameter.arg, SymbolUsage::Parameter)
-        }
+            SymbolUsage::Parameter
+        };
+        self.regsiter_name(&parameter.arg, usage)
     }
 
     fn scan_parameters_annotations(&mut self, parameters: &[ast::Parameter]) -> SymbolTableResult {
diff --git a/vm/src/stdlib/symtable.rs b/vm/src/stdlib/symtable.rs
@@ -249,7 +249,7 @@ impl PySymbol {
 
     #[pymethod(name = "is_namespace")]
     fn is_namespace(&self) -> bool {
-        self.namespaces.len() > 0
+        self.namespaces.is_empty()
     }
 
     #[pymethod(name = "is_annotated")]
