From 7fd9e86ea694bcfc3cb8472d43c93626febd45cd Mon Sep 17 00:00:00 2001
From: Nicolas Williams <nico@cryptonector.com>
Date: Tue, 6 Mar 2018 13:55:16 -0600
Subject: Make limit/2 more efficient

Contributed by @pkoppstein.
---
 src/builtin.jq | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/src/builtin.jq b/src/builtin.jq
index c445f1a2..e65a8997 100644
--- a/src/builtin.jq
+++ b/src/builtin.jq
@@ -168,13 +168,9 @@ def until(cond; next):
          if cond then . else (next|_until) end;
      _until;
 def limit($n; exp):
-  if $n < 0 then exp else
-    label $out |
-    foreach exp as $item (
-      [$n, null];
-      if .[0] < 1 then break $out
-        else [.[0] -1, $item] end;
-      if .[0] == 0 then .[1], break $out else .[1] end) end;
+  if $n < 0 then exp
+  else label $out | foreach exp as $item ($n; .-1; $item, if . <= 0 then break $out else empty end)
+  end;
 def isempty(g): 0 == ((label $go | g | (1, break $go)) // 0);
 def first(g): label $out | g | ., break $out;
 def last(g): reduce g as $item (null; $item);
-- 
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