Update instructions to apply to Guile

Also rename `main` to `main.lua` and `main.scm` to `main`.

1 files changed, 29 insertions, 0 deletions

diff --git a/main.lua b/main.lua
new file mode 100755
index 0000000..38189ee
--- /dev/null
+++ b/main.lua
@@ -0,0 +1,29 @@
+#!/usr/bin/lua
+
+if #arg < 1 or #arg > 2 then
+    error ("Syntax: %s <DAY><a|b> [inputfile]"):format(arg[0])
+    os.exit(1)
+end
+
+local num, letter = arg[1]:match("^(%d+)([ab])$")
+if not num then
+    error ('Expected <DAY><a|b> as first argument (e.g. "01b"), got: %s'):format(arg[1])
+    os.exit(1)
+end
+num = tonumber(num)
+
+local script = ("%02d.lua"):format(num)
+local infile = arg[2] or ("%02d.in"):format(num)
+local input_stream = io.open(infile)
+if input_stream then
+    io.input(input_stream)
+else
+    print "Reading from standard input."
+end
+
+local parsed = loadfile(script)()
+if letter == 'a' then
+    parsed:part1()
+else
+    parsed:part2()
+end