diff --git a/crates/compiler/src/evaluate/css_tree.rs b/crates/compiler/src/evaluate/css_tree.rs
index bcf0e5d..98ec097 100644
--- a/crates/compiler/src/evaluate/css_tree.rs
+++ b/crates/compiler/src/evaluate/css_tree.rs
@@ -78,28 +78,27 @@ impl CssTree {
     }
 
     fn add_child_to_parent(&self, child: CssStmt, parent_idx: CssTreeIdx) {
-        let mut parent = self.stmts[parent_idx.0].borrow_mut().take();
-        match &mut parent {
-            Some(CssStmt::RuleSet { body, .. }) => body.push(child),
-            Some(CssStmt::Style(..) | CssStmt::Comment(..) | CssStmt::Import(..)) | None => {
-                unreachable!()
-            }
-            Some(CssStmt::Media(media, ..)) => {
-                media.body.push(child);
-            }
-            Some(CssStmt::UnknownAtRule(at_rule, ..)) => {
-                at_rule.body.push(child);
-            }
-            Some(CssStmt::Supports(supports, ..)) => {
-                supports.body.push(child);
-            }
-            Some(CssStmt::KeyframesRuleSet(keyframes)) => {
-                keyframes.body.push(child);
-            }
-        }
-        self.stmts[parent_idx.0]
-            .borrow_mut()
-            .replace(parent.unwrap());
+        RefMut::map(self.stmts[parent_idx.0].borrow_mut(), |parent| {
+            match parent {
+                Some(CssStmt::RuleSet { body, .. }) => body.push(child),
+                Some(CssStmt::Style(..) | CssStmt::Comment(..) | CssStmt::Import(..)) | None => {
+                    unreachable!()
+                }
+                Some(CssStmt::Media(media, ..)) => {
+                    media.body.push(child);
+                }
+                Some(CssStmt::UnknownAtRule(at_rule, ..)) => {
+                    at_rule.body.push(child);
+                }
+                Some(CssStmt::Supports(supports, ..)) => {
+                    supports.body.push(child);
+                }
+                Some(CssStmt::KeyframesRuleSet(keyframes)) => {
+                    keyframes.body.push(child);
+                }
+            };
+            parent
+        });
     }
 
     pub fn add_child(&mut self, child: CssStmt, parent_idx: CssTreeIdx) -> CssTreeIdx {
diff --git a/crates/compiler/src/evaluate/visitor.rs b/crates/compiler/src/evaluate/visitor.rs
index 9f7b9e2..81b5991 100644
--- a/crates/compiler/src/evaluate/visitor.rs
+++ b/crates/compiler/src/evaluate/visitor.rs
@@ -2125,26 +2125,25 @@ impl<'a> Visitor<'a> {
                     evaluated.span,
                 )?;
 
-                // todo: superfluous clone
-                let declared_arguments = func.arguments().args.clone();
+                let declared_arguments = &func.arguments().args;
                 let min_len = evaluated.positional.len().min(declared_arguments.len());
 
+                let positional_len = evaluated.positional.len();
+
                 #[allow(clippy::needless_range_loop)]
-                for i in 0..min_len {
-                    // todo: superfluous clone
+                for i in (0..min_len).rev() {
                     visitor.env.scopes_mut().insert_var_last(
                         declared_arguments[i].name,
-                        evaluated.positional[i].clone(),
+                        evaluated.positional.remove(i),
                     );
                 }
 
                 // todo: better name for var
-                let additional_declared_args =
-                    if declared_arguments.len() > evaluated.positional.len() {
-                        &declared_arguments[evaluated.positional.len()..declared_arguments.len()]
-                    } else {
-                        &[]
-                    };
+                let additional_declared_args = if declared_arguments.len() > positional_len {
+                    &declared_arguments[positional_len..declared_arguments.len()]
+                } else {
+                    &[]
+                };
 
                 for argument in additional_declared_args {
                     let name = argument.name;
@@ -2161,17 +2160,19 @@ impl<'a> Visitor<'a> {
 
                 let were_keywords_accessed = Arc::new(Cell::new(false));
 
-                let argument_list = if let Some(rest_arg) = func.arguments().rest {
-                    let rest = if evaluated.positional.len() > declared_arguments.len() {
-                        &evaluated.positional[declared_arguments.len()..]
+                let num_named_args = evaluated.named.len();
+
+                let has_arg_list = if let Some(rest_arg) = func.arguments().rest {
+                    let rest = if evaluated.positional.len() > 0 {
+                        evaluated.positional
                     } else {
-                        &[]
+                        Vec::new()
                     };
 
                     let arg_list = Value::ArgList(ArgList::new(
-                        rest.to_vec(),
-                        // todo: superfluous clone
+                        rest,
                         Arc::clone(&were_keywords_accessed),
+                        // todo: superfluous clone
                         evaluated.named.clone(),
                         if evaluated.separator == ListSeparator::Undecided {
                             ListSeparator::Comma
@@ -2180,20 +2181,16 @@ impl<'a> Visitor<'a> {
                         },
                     ));
 
-                    visitor
-                        .env
-                        .scopes_mut()
-                        // todo: superfluous clone
-                        .insert_var_last(rest_arg, arg_list.clone());
+                    visitor.env.scopes_mut().insert_var_last(rest_arg, arg_list);
 
-                    Some(arg_list)
+                    true
                 } else {
-                    None
+                    false
                 };
 
                 let val = run(func, visitor)?;
 
-                if argument_list.is_none() || evaluated.named.is_empty() {
+                if !has_arg_list || num_named_args == 0 {
                     return Ok(val);
                 }
 
@@ -2201,7 +2198,7 @@ impl<'a> Visitor<'a> {
                     return Ok(val);
                 }
 
-                let argument_word = if evaluated.named.len() == 1 {
+                let argument_word = if num_named_args == 1 {
                     "argument"
                 } else {
                     "arguments"
diff --git a/crates/compiler/src/serializer.rs b/crates/compiler/src/serializer.rs
index eccd3c4..72f4855 100644
--- a/crates/compiler/src/serializer.rs
+++ b/crates/compiler/src/serializer.rs
@@ -13,8 +13,8 @@ use crate::{
     },
     utils::hex_char_for,
     value::{
-        fuzzy_equals, ArgList, CalculationArg, SassCalculation, SassFunction, SassMap, SassNumber,
-        Value,
+        fuzzy_equals, ArgList, CalculationArg, CalculationName, SassCalculation, SassFunction,
+        SassMap, SassNumber, Value,
     },
     Options,
 };
@@ -299,10 +299,17 @@ impl<'a> Serializer<'a> {
         self.write_optional_space();
     }
 
+    fn write_calculation_name(&mut self, name: CalculationName) {
+        match name {
+            CalculationName::Calc => self.buffer.extend_from_slice(b"calc"),
+            CalculationName::Min => self.buffer.extend_from_slice(b"min"),
+            CalculationName::Max => self.buffer.extend_from_slice(b"max"),
+            CalculationName::Clamp => self.buffer.extend_from_slice(b"clamp"),
+        }
+    }
+
     fn visit_calculation(&mut self, calculation: &SassCalculation) -> SassResult<()> {
-        // todo: superfluous allocation
-        self.buffer
-            .extend_from_slice(calculation.name.to_string().as_bytes());
+        self.write_calculation_name(calculation.name);
         self.buffer.push(b'(');
 
         if let Some((last, slice)) = calculation.args.split_last() {