diff --git a/argparse/help_render.mbt b/argparse/help_render.mbt
index 39d3e1780..6a7a1ccf2 100644
--- a/argparse/help_render.mbt
+++ b/argparse/help_render.mbt
@@ -240,25 +240,22 @@ fn builtin_option_label(
 
 ///|
 fn positional_entries(cmd : Command) -> Array[String] {
-  let display = Array::new(capacity=cmd.args.length())
-  for arg in positional_args(cmd.args) {
-    if arg.hidden {
-      continue
-    }
-    display.push((positional_display(arg), arg_doc(arg)))
-  }
-  format_entries(display)
+  format_entries(
+    [
+      for arg in positional_args(cmd.args) if !arg.hidden => {
+        (positional_display(arg), arg_doc(arg))
+      }
+    ],
+  )
 }
 
 ///|
 fn subcommand_entries(cmd : Command) -> Array[String] {
-  let display = Array::new(capacity=cmd.subcommands.length() + 1)
-  for sub in cmd.subcommands {
-    if sub.hidden {
-      continue
+  let display = [
+    for sub in cmd.subcommands if !sub.hidden => {
+      (sub.name, sub.about.unwrap_or(""))
     }
-    display.push((sub.name, sub.about.unwrap_or("")))
-  }
+  ]
   if help_subcommand_enabled(cmd) {
     display.push(("help", "Print help for the subcommand(s)."))
   }
@@ -267,7 +264,7 @@ fn subcommand_entries(cmd : Command) -> Array[String] {
 
 ///|
 fn group_entries(cmd : Command) -> Array[String] {
-  let display = Array::new(capacity=cmd.groups.length())
+  let display = []
   for group in cmd.groups {
     let members = group_members(cmd, group)
     if members == "" {
@@ -428,16 +425,11 @@ fn group_label(group : ArgGroup) -> String {
 
 ///|
 fn group_members(cmd : Command, group : ArgGroup) -> String {
-  let members = []
-  for arg in cmd.args {
-    if arg.hidden {
-      continue
-    }
-    if arg_in_group(arg, group) {
-      members.push(group_member_display(arg))
+  [
+    for arg in cmd.args if !arg.hidden && arg_in_group(arg, group) => {
+      group_member_display(arg)
     }
-  }
-  members.join(", ")
+  ].join(", ")
 }
 
 ///|
diff --git a/bytes/internal/regex_engine/translate.mbt b/bytes/internal/regex_engine/translate.mbt
index 09edf53eb..9d9eb9ed9 100644
--- a/bytes/internal/regex_engine/translate.mbt
+++ b/bytes/internal/regex_engine/translate.mbt
@@ -39,11 +39,11 @@ fn translate(
     Sequence(exprs) => (transl_seq(tc, exprs), pref)
     Alternation(exprs) => {
       // TODO: merge sequences
-      let alts = []
-      for expr in exprs {
-        let (cr, pref2) = translate(tc, expr)
-        alts.push(enforce_pref(ctx, pref, pref2, cr))
-      }
+      let alts = [
+        for expr in exprs if translate(tc, expr) is (cr, pref2) => {
+          enforce_pref(ctx, pref, pref2, cr)
+        }
+      ]
       (@automata.e_alt(ctx~, alts), pref)
     }
     Quantifier(q, expr) => {
diff --git a/priority_queue/priority_queue.mbt b/priority_queue/priority_queue.mbt
index d2c2e419c..a80aff59c 100644
--- a/priority_queue/priority_queue.mbt
+++ b/priority_queue/priority_queue.mbt
@@ -142,11 +142,7 @@ pub fn[A : Compare] PriorityQueue::iter(self : PriorityQueue[A]) -> Iter[A] {
 
 ///|
 pub impl[A : ToJson + Compare] ToJson for PriorityQueue[A] with to_json(self) {
-  let arr = []
-  for x in self {
-    arr.push(x.to_json())
-  }
-  Json::array(arr)
+  Json::array([ for x in self => x.to_json() ])
 }
 
 ///|