diff --git a/src/builtins/lists.rs b/src/builtins/lists.rs
index 45343bc5..bbd6a93d 100644
--- a/src/builtins/lists.rs
+++ b/src/builtins/lists.rs
@@ -193,7 +193,7 @@ pub fn foldl(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Calcit, Cal
         },
       ) => {
         for x in xs {
-          let values = TernaryTreeList::from(&vec![ret, x.to_owned()]);
+          let values = TernaryTreeList::from(&[ret, x.to_owned()]);
           ret = runner::run_fn(&values, scope, args, body, def_ns.to_owned(), call_stack)?;
         }
         Ok(ret)
@@ -201,7 +201,7 @@ pub fn foldl(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Calcit, Cal
       (Calcit::List(xs), Calcit::Proc(proc)) => {
         for x in xs {
           // println!("foldl args, {} {}", ret, x.to_owned());
-          ret = builtins::handle_proc(proc, &TernaryTreeList::from(&vec![ret, x.to_owned()]), call_stack)?;
+          ret = builtins::handle_proc(proc, &TernaryTreeList::from(&[ret, x.to_owned()]), call_stack)?;
         }
         Ok(ret)
       }
@@ -213,7 +213,7 @@ pub fn foldl(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Calcit, Cal
         },
       ) => {
         for x in xs {
-          let values = TernaryTreeList::from(&vec![ret, x.to_owned()]);
+          let values = TernaryTreeList::from(&[ret, x.to_owned()]);
           ret = runner::run_fn(&values, scope, args, body, def_ns.to_owned(), call_stack)?;
         }
         Ok(ret)
@@ -221,7 +221,7 @@ pub fn foldl(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Calcit, Cal
       (Calcit::Set(xs), Calcit::Proc(proc)) => {
         for x in xs {
           // println!("foldl args, {} {}", ret, x.to_owned());
-          ret = builtins::handle_proc(proc, &TernaryTreeList::from(&vec![ret, x.to_owned()]), call_stack)?;
+          ret = builtins::handle_proc(proc, &TernaryTreeList::from(&[ret, x.to_owned()]), call_stack)?;
         }
         Ok(ret)
       }
@@ -233,7 +233,7 @@ pub fn foldl(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Calcit, Cal
         },
       ) => {
         for (k, x) in xs {
-          let values = TernaryTreeList::from(&vec![ret, Calcit::List(TernaryTreeList::from(&vec![k.to_owned(), x.to_owned()]))]);
+          let values = TernaryTreeList::from(&[ret, Calcit::List(TernaryTreeList::from(&[k.to_owned(), x.to_owned()]))]);
           ret = runner::run_fn(&values, scope, args, body, def_ns.to_owned(), call_stack)?;
         }
         Ok(ret)
@@ -243,7 +243,7 @@ pub fn foldl(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Calcit, Cal
           // println!("foldl args, {} {}", ret, x.to_owned());
           ret = builtins::handle_proc(
             proc,
-            &TernaryTreeList::from(&vec![ret, Calcit::List(TernaryTreeList::from(&vec![k.to_owned(), x.to_owned()]))]),
+            &TernaryTreeList::from(&[ret, Calcit::List(TernaryTreeList::from(&[k.to_owned(), x.to_owned()]))]),
             call_stack,
           )?;
         }
@@ -279,7 +279,7 @@ pub fn foldl_shortcut(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Ca
       ) => {
         let mut state = acc.to_owned();
         for x in xs {
-          let values = TernaryTreeList::from(&vec![state, x.to_owned()]);
+          let values = TernaryTreeList::from(&[state, x.to_owned()]);
           let pair = runner::run_fn(&values, scope, args, body, def_ns.to_owned(), call_stack)?;
           match pair {
             Calcit::Tuple(x0, x1) => match &*x0 {
@@ -316,7 +316,7 @@ pub fn foldl_shortcut(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Ca
       ) => {
         let mut state = acc.to_owned();
         for x in xs {
-          let values = TernaryTreeList::from(&vec![state, x.to_owned()]);
+          let values = TernaryTreeList::from(&[state, x.to_owned()]);
           let pair = runner::run_fn(&values, scope, args, body, def_ns.to_owned(), call_stack)?;
           match pair {
             Calcit::Tuple(x0, x1) => match &*x0 {
@@ -353,7 +353,7 @@ pub fn foldl_shortcut(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Ca
       ) => {
         let mut state = acc.to_owned();
         for (k, x) in xs {
-          let values = TernaryTreeList::from(&vec![state, Calcit::List(TernaryTreeList::from(&vec![k.to_owned(), x.to_owned()]))]);
+          let values = TernaryTreeList::from(&[state, Calcit::List(TernaryTreeList::from(&[k.to_owned(), x.to_owned()]))]);
           let pair = runner::run_fn(&values, scope, args, body, def_ns.to_owned(), call_stack)?;
           match pair {
             Calcit::Tuple(x0, x1) => match &*x0 {
@@ -413,7 +413,7 @@ pub fn foldr_shortcut(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Ca
         let size = xs.len();
         for i in 0..size {
           let x = xs[size - 1 - i].to_owned();
-          let values = TernaryTreeList::from(&vec![state, x]);
+          let values = TernaryTreeList::from(&[state, x]);
           let pair = runner::run_fn(&values, scope, args, body, def_ns.to_owned(), call_stack)?;
           match pair {
             Calcit::Tuple(x0, x1) => match &*x0 {
@@ -467,7 +467,7 @@ pub fn sort(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Calcit, Calc
       ) => {
         let mut xs2: Vec<&Calcit> = xs.into_iter().collect::<Vec<&Calcit>>();
         xs2.sort_by(|a, b| -> Ordering {
-          let values = TernaryTreeList::from(&vec![a.to_owned().to_owned(), b.to_owned().to_owned()]);
+          let values = TernaryTreeList::from(&[a.to_owned().to_owned(), b.to_owned().to_owned()]);
           let v = runner::run_fn(&values, scope, args, body, def_ns.to_owned(), call_stack);
           match v {
             Ok(Calcit::Number(x)) if x < 0.0 => Ordering::Less,
@@ -493,7 +493,7 @@ pub fn sort(xs: &CalcitItems, call_stack: &CallStackList) -> Result<Calcit, Calc
       (Calcit::List(xs), Calcit::Proc(proc)) => {
         let mut xs2: Vec<&Calcit> = xs.into_iter().collect::<Vec<&Calcit>>();
         xs2.sort_by(|a, b| -> Ordering {
-          let values = TernaryTreeList::from(&vec![a.to_owned().to_owned(), b.to_owned().to_owned()]);
+          let values = TernaryTreeList::from(&[a.to_owned().to_owned(), b.to_owned().to_owned()]);
           let v = builtins::handle_proc(proc, &values, call_stack);
           match v {
             Ok(Calcit::Number(x)) if x < 0.0 => Ordering::Less,
diff --git a/src/builtins/maps.rs b/src/builtins/maps.rs
index 6cd88816..8d4cc024 100644
--- a/src/builtins/maps.rs
+++ b/src/builtins/maps.rs
@@ -142,7 +142,7 @@ pub fn to_list(xs: &CalcitItems) -> Result<Calcit, CalcitErr> {
     Some(Calcit::Map(m)) => {
       let mut ys: TernaryTreeList<Calcit> = TernaryTreeList::Empty;
       for (k, v) in m {
-        let zs: TernaryTreeList<Calcit> = TernaryTreeList::from(&vec![k.to_owned(), v.to_owned()]);
+        let zs: TernaryTreeList<Calcit> = TernaryTreeList::from(&[k.to_owned(), v.to_owned()]);
         ys = ys.push(Calcit::List(zs));
       }
       Ok(Calcit::List(ys))
@@ -196,7 +196,7 @@ pub fn first(xs: &CalcitItems) -> Result<Calcit, CalcitErr> {
   match xs.get(0) {
     Some(Calcit::Map(ys)) => match ys.iter().next() {
       // TODO order may not be stable enough
-      Some((k, v)) => Ok(Calcit::List(TernaryTreeList::from(&vec![k.to_owned(), v.to_owned()]))),
+      Some((k, v)) => Ok(Calcit::List(TernaryTreeList::from(&[k.to_owned(), v.to_owned()]))),
       None => Ok(Calcit::Nil),
     },
     Some(a) => CalcitErr::err_str(format!("map:first expected a map, got: {}", a)),
diff --git a/src/builtins/refs.rs b/src/builtins/refs.rs
index 6720d986..70f1585b 100644
--- a/src/builtins/refs.rs
+++ b/src/builtins/refs.rs
@@ -35,7 +35,7 @@ fn modify_ref(path: Arc<str>, v: Calcit, call_stack: &CallStackList) -> Result<(
       Calcit::Fn {
         def_ns, scope, args, body, ..
       } => {
-        let values = TernaryTreeList::from(&vec![v.to_owned(), prev.to_owned()]);
+        let values = TernaryTreeList::from(&[v.to_owned(), prev.to_owned()]);
         runner::run_fn(&values, scope, args, body, def_ns.to_owned(), call_stack)?;
       }
       a => {
diff --git a/src/runner/preprocess.rs b/src/runner/preprocess.rs
index 24b89e57..81701383 100644
--- a/src/runner/preprocess.rs
+++ b/src/runner/preprocess.rs
@@ -315,7 +315,7 @@ fn process_list_call(
   match (head_form.to_owned(), head_evaled) {
     (Calcit::Keyword(..), _) => {
       if args.len() == 1 {
-        let code = Calcit::List(TernaryTreeList::from(&vec![
+        let code = Calcit::List(TernaryTreeList::from(&[
           Calcit::Symbol {
             sym: String::from("get").into(),
             ns: String::from(primes::CORE_NS).into(),