added simple parser for .rle format

1 files changed, 95 insertions, 0 deletions

diff --git a/parsers/rle.lua b/parsers/rle.lua
new file mode 100644
index 0000000..cd10493
--- /dev/null
+++ b/parsers/rle.lua
@@ -0,0 +1,95 @@
+-- http://psoup.math.wisc.edu/mcell/ca_files_formats.html#RLE
+local C, Cs, Ct, P, R, S, match = lpeg.C, lpeg.Cs, lpeg.Ct, lpeg.P, lpeg.R, lpeg.S, lpeg.match
+
+local rows = {}
+local coords = {}
+
+local n_row = 1
+rows[n_row] = ""
+
+local eol = P"\n"
+local hashmark = P"#"
+local space = S" \t"
+local whitespace = S(" \n\t")^0
+local num = R"09"
+local comma = P","
+local exclam = P"!"
+local equals = P"="
+local dollar = P"$"
+local state = S"bo"
+--local sign = S("+-")^0 -- support negative grid values? not yet
+
+local comment = hashmark * (1-eol)^0 * eol
+
+local getx = space^0 * P"x" * space^0 * equals * space^0 * C(num^1) / function (x)
+    coords.x = tonumber(x)
+end
+local gety = space^0 * P"y" * space^0 * equals * space^0 * C(num^1) / function (y) 
+    coords.y = tonumber(y)
+end
+geometry = getx * comma * gety * (1-eol)^0 * eol
+
+local function n_of_t (n, c)
+    local tmp = ""
+    if c == "o" then -- live
+        c = "1"
+    else -- dead
+        c = "0"
+    end
+
+    for i=1, n, 1 do
+        tmp = tmp .. c
+    end
+    return tmp
+end
+
+local cell = C(num^0) * C(state) / function (n, c)
+    if n == "" then
+        n = 1
+    end
+
+    if  n_of_t (tonumber(n), c) == nil then
+        print("OVER HERE", n_row,n, c)
+    end
+    rows[n_row] = rows[n_row] .. n_of_t (tonumber(n), c)
+end
+
+local line = whitespace * (cell * whitespace)^0 * C(num^0) / function (empty) 
+
+    if rows[n_row]:len() < coords.x then -- fill grid with dead cells
+        rows[n_row] = rows[n_row] .. n_of_t( coords.x - rows[n_row]:len(), "0" ) 
+    end
+        
+    if empty ~= "" then
+        for n=1, tonumber(empty)-1, 1 do
+            n_row = n_row + 1 
+            rows[n_row] = n_of_t( coords.x, "0" )
+        end
+    end
+
+    n_row = n_row + 1 
+
+    if n_row <= coords.y then
+        rows[n_row] = "" 
+    end
+end
+
+local p_rle = comment^0 * geometry * line * (dollar * line)^0 * whitespace * exclam
+
+local function parser(fname)
+    local file = assert(io.open(fname, "r"), "Not a file: " .. fname)
+    local data = file:read("*all")
+    file:close()
+
+    if p_rle:match(data) then
+        if context then
+            context.writestatus("simpleslides", "Sucessfully loaded frame from "..fname..".")
+        end
+        return rows
+    else
+        return false
+    end
+end
+
+return parser
+