From bed37dc2375987bd6be39760028bc099b25246a5 Mon Sep 17 00:00:00 2001
From: joachimschmidt557 <joachim.schmidt557@outlook.com>
Date: Thu, 4 Apr 2019 08:08:04 +0200
Subject: [PATCH] Performance improvement in tac

---
 tac.nim | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/tac.nim b/tac.nim
index c71c26c..4a55530 100644
--- a/tac.nim
+++ b/tac.nim
@@ -9,18 +9,17 @@ proc catFile(file:string) =
         f = open(file, fmRead)
         reverseLines: seq[string]
     for line in lines(f):
-        reverseLines = line & reverseLines
-    for line in reverseLines:
-        writeLine(stdout, line)
+        reverseLines.add(line)
+    for i in low(reverseLines)..high(reverseLines):
+        writeLine(stdout, reverseLines[high(reverseLines) - i])
 
 proc catStdin() =
     var
-        line = ""
         reverseLines: seq[string]
-    while stdin.readLine(line):
-        reverseLines = line & reverseLines
-    for line in reverseLines:
-        writeLine(stdout, line)
+    for line in lines(stdin):
+        reverseLines.add(line)
+    for i in low(reverseLines)..high(reverseLines):
+        writeLine(stdout, reverseLines[high(reverseLines) - i])
 
 proc main(files:seq[string]) =
     if files.len == 0: