From 2e2ea4b49f9f3101b4e09b77cd33fefc93c9c3cf Mon Sep 17 00:00:00 2001
From: Philipp Gesang <pgesang@ix.urz.uni-heidelberg.de>
Date: Sun, 15 Aug 2010 01:39:09 +0200
Subject: drawing Wolfram automata (inefficient)

---
 eca.lua | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100644 eca.lua

(limited to 'eca.lua')

diff --git a/eca.lua b/eca.lua
new file mode 100644
index 0000000..6c49e8d
--- /dev/null
+++ b/eca.lua
@@ -0,0 +1,109 @@
+--
+--------------------------------------------------------------------------------
+--         FILE:  eca.lua
+--        USAGE:  ./eca.lua 
+--  DESCRIPTION:  drawing elementary cellular automata
+--      OPTIONS:  ---
+-- REQUIREMENTS:  ---
+--         BUGS:  ---
+--        NOTES:  ---
+--       AUTHOR:  Philipp Gesang (Phg), <megas.kapaneus@gmail.com>
+--      COMPANY:  
+--      VERSION:  1.0
+--      CREATED:  14/08/10 19:43:35 CEST
+--     REVISION:  ---
+--------------------------------------------------------------------------------
+--
+
+require "life"
+
+local help = gol.helpers
+
+local C, Cs, Ct, P, R, S, match = lpeg.C, lpeg.Cs, lpeg.Ct, lpeg.P, lpeg.R, lpeg.S, lpeg.match
+
+
+eca = {}
+
+
+function eca.parse_file (fname)
+    local f = assert(io.open(fname, "r"), "No such file: "..fname..".")
+    local init = f:read("*all")
+    f:close()
+
+    return help.strip(init)
+end
+
+function eca.to_base(number, base)
+    local alphabet, result, cnt, remainder = "0123456789abcdef", "", 0                   
+    while number > 0 do
+        cnt = cnt + 1 
+        number, remainder = math.floor(number / base), (number % base) + 1 
+        result = string.sub(alphabet, remainder, remainder) .. result
+    end 
+    return result
+end
+
+function eca.gen_rule(nr)
+    local rules = {}
+    local states = { "111", "110", "101", "100", "011", "010", "001", "000" }
+    
+    nr = string.format("%8s",eca.to_base(nr, 2)):gsub(" ", "0")
+
+    local n = 1
+    while n <= #states  do
+        rules[states[n]] = nr:sub(n,n)
+        n = n + 1
+    end
+
+    return rules
+end
+
+function eca.next_line(from, rule)
+    local new = ""
+    from = "0"..from.."0"  -- assume dead borders
+    --from = string.format("0%s0", from)
+
+    local cell = C(S"01")
+    local cells= Ct(cell * #(cell * cell)) / function (t)
+        local three = t[1]..t[2]..t[3]
+        new = new .. rule[three]
+    end
+    lpeg.match(cells^1, from)
+    return new
+end
+
+function eca.gen_frame(from, lines, rule)
+    local new = { [1] = from }
+
+    local cnt = 1
+    local tmp
+    repeat
+        --print(cnt)
+        tmp = eca.next_line(from, rule)
+        table.insert( new, tmp )
+        from = tmp
+        cnt = cnt + 1
+    until cnt == lines
+    --for i,j in ipairs(new) do
+        --print (string.format("%3s >> %s",i,j))
+    --end
+    return eca.next_line(tmp, rule), new
+end
+
+function eca.successive (current)
+    --if not current then print("NOPE")return 1 end
+    --local current = current or {}
+
+    local thisframe
+    current.from, thisframe = eca.gen_frame(current.from, current.framesize, current.rule)
+    if not context then -- cli invocation
+        for _,j in ipairs(thisframe) do 
+            io.write(j:gsub("0","·"):gsub("1","O").."\n") 
+        end
+    else
+        
+    end
+    return 0
+end
+
+return eca
-- 
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