From 6fbe2f4e31051b2ecc881d9f476c61fe08b5b43b Mon Sep 17 00:00:00 2001
From: Abigail <abigail@abigail.be>
Date: Mon, 18 Oct 2021 23:44:35 +0200
Subject: Lua solutions for week 135

---
 challenge-135/abigail/README.md    |  2 ++
 challenge-135/abigail/lua/ch-1.lua | 27 +++++++++++++++++++++++++++
 challenge-135/abigail/lua/ch-2.lua | 31 +++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+)
 create mode 100644 challenge-135/abigail/lua/ch-1.lua
 create mode 100644 challenge-135/abigail/lua/ch-2.lua

diff --git a/challenge-135/abigail/README.md b/challenge-135/abigail/README.md
index 1e8d468c68..9f6cb7b1ff 100644
--- a/challenge-135/abigail/README.md
+++ b/challenge-135/abigail/README.md
@@ -5,6 +5,7 @@
 * [AWK](awk/ch-1.awk)
 * [Bash](bash/ch-1.sh)
 * [C](c/ch-1.c)
+* [Lua](lua/ch-1.lua)
 * [Node.js](node/ch-1.js)
 * [Perl](perl/ch-1.pl)
 
@@ -13,5 +14,6 @@
 * [AWK](awk/ch-2.awk)
 * [Bash](bash/ch-2.sh)
 * [C](c/ch-2.c)
+* [Lua](lua/ch-2.lua)
 * [Node.js](node/ch-2.js)
 * [Perl](perl/ch-2.pl)
diff --git a/challenge-135/abigail/lua/ch-1.lua b/challenge-135/abigail/lua/ch-1.lua
new file mode 100644
index 0000000000..b5db984457
--- /dev/null
+++ b/challenge-135/abigail/lua/ch-1.lua
@@ -0,0 +1,27 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-1.lua < input-file
+--
+
+for line in io . lines () do
+    line = line : gsub ("^[-+]%s*", "")
+    if line : find ("%D") then
+        print ("not an integer")
+    else
+        if line : len () % 2 == 0 then
+            print ("even number of digits")
+        else
+            if line : len () < 3 then
+                print ("too short")
+            else
+                local start = 1 + (line : len () - 3) / 2
+                print (line : sub (start , start + 2))
+            end
+        end
+    end
+end
diff --git a/challenge-135/abigail/lua/ch-2.lua b/challenge-135/abigail/lua/ch-2.lua
new file mode 100644
index 0000000000..e6b70b2830
--- /dev/null
+++ b/challenge-135/abigail/lua/ch-2.lua
@@ -0,0 +1,31 @@
+#!/opt/local/bin/lua
+
+--
+-- See ../README.md
+--
+
+--
+-- Run as: lua ch-2.lua < input-file
+--
+
+local w = {1, 3, 1, 7, 3, 9, 1}
+
+for line in io . lines () do
+    if line : find ("^[0-9BCDFGHJKLMNPQRSTVWXYZ]*$") then
+        local check = 0
+        for i = 1, 7 do
+            local byte = string . byte (line : sub (i, i))
+            if   byte <= string . byte ("9")
+            then byte  = byte - string . byte ("0")
+            else byte  = byte - string . byte ("A") + 10
+            end
+            check = check + w [i] * byte
+         end
+         if check % 10 == 0
+         then print (1)
+         else print (0)
+         end
+    else
+        print (0)
+    end
+end
-- 
cgit