From 21aa0b8d842218b4cfa59830cf85df71730a0487 Mon Sep 17 00:00:00 2001
From: Charlie Marsh <crmarsh416@gmail.com>
Date: Mon, 19 Jun 2023 15:32:58 -0400
Subject: [PATCH] Optimize `validate_arguments` (#10)

---
 parser/src/function.rs | 13 +++++++++----
 parser/src/parser.rs   |  2 +-
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/parser/src/function.rs b/parser/src/function.rs
index 53ca0879..201a43b1 100644
--- a/parser/src/function.rs
+++ b/parser/src/function.rs
@@ -16,7 +16,14 @@ pub(crate) struct ArgumentList {
 
 // Perform validation of function/lambda arguments in a function definition.
 pub(crate) fn validate_arguments(arguments: &ast::Arguments) -> Result<(), LexicalError> {
-    let mut all_arg_names = FxHashSet::with_hasher(Default::default());
+    let mut all_arg_names = FxHashSet::with_capacity_and_hasher(
+        arguments.posonlyargs.len()
+            + arguments.args.len()
+            + arguments.vararg.is_some() as usize
+            + arguments.kwonlyargs.len()
+            + arguments.kwarg.is_some() as usize,
+        Default::default(),
+    );
 
     let posonlyargs = arguments.posonlyargs.iter();
     let args = arguments.args.iter();
@@ -83,7 +90,7 @@ pub(crate) fn parse_args(func_args: Vec<FunctionArgument>) -> Result<ArgumentLis
             Some((start, end, name)) => {
                 // Check for duplicate keyword arguments in the call.
                 if let Some(keyword_name) = &name {
-                    if keyword_names.contains(keyword_name) {
+                    if !keyword_names.insert(keyword_name.clone()) {
                         return Err(LexicalError {
                             error: LexicalErrorType::DuplicateKeywordArgumentError(
                                 keyword_name.to_string(),
@@ -91,8 +98,6 @@ pub(crate) fn parse_args(func_args: Vec<FunctionArgument>) -> Result<ArgumentLis
                             location: start,
                         });
                     }
-
-                    keyword_names.insert(keyword_name.clone());
                 } else {
                     double_starred = true;
                 }
diff --git a/parser/src/parser.rs b/parser/src/parser.rs
index 95e740cb..398a9a5e 100644
--- a/parser/src/parser.rs
+++ b/parser/src/parser.rs
@@ -1104,7 +1104,7 @@ def args_to_tuple(*args: *Ts) -> Tuple[*Ts]: ...
     #[test]
     #[cfg(feature = "all-nodes-with-ranges")]
     fn decorator_ranges() {
-        let parse_ast = parse_program(
+        let parse_ast = ast::Suite::parse(
             r#"
 @my_decorator
 def test():