start of splubp prototype

splubp.p8

@@ -0,0 +1,97 @@
+pico-8 cartridge // http://www.pico-8.com
+version 42
+__lua__
+-- splubp data transport
+-- by kistaro windrider
+
+-- main
+
+-- >8
+-- utilities
+
+-- generate standard "overlay"
+-- constructor for type tt.
+-- if tt.init is defined, generated
+-- new calls tt.init(ret) after
+-- ret is definitely not nil,
+-- after calling setmetatable.
+-- use to initialize mutables.
+--
+-- if there was a previous new,
+-- it is invoked before
+-- setting tt's metatable, so
+-- each new will see its
+-- inheritance chain.
+function mknew(tt)
+ local mt,oldinit,more = {__index=tt},tt.superinit,rawget(tt, "init")
+ tt.new=function(ret)
+  if(not ret) ret = {}
+  ret.new = false
+  setmetatable(ret, mt)
+  if(oldinit) oldinit(ret)
+  if (more) more(ret)
+  return ret
+ end
+
+ if oldinit and more then
+  tt.superinit = function(ret)
+   oldinit(ret)
+   more(ret)
+  end
+ elseif more then
+  tt.superinit = more
+ end
+ return tt
+end
+
+function set(t)
+ local ret = {}
+ for v in all(t) do
+  ret[v]=true
+ end
+ return ret
+end
+
+whitespace = set(split" ,\t,\n")
+
+function trim(s)
+ local f, e = 1, #s
+ while (f <= e and whitespace[s[f]]) f += 1
+ while (e >= f and whitespace[s[e]]) e -= 1
+ if (f<e) return sub(s,f,e)
+ return ""
+end
+
+-- >8
+-- writer
+
+splubp_writer = mknew{
+ init = function(self)
+  -- fill from single file
+  self.fmts = self.fmts or {}
+  if self.ffile then
+   for f in all(split(self.ffile, "===", false)) do
+    local ext, fmt = split(f, "---")
+    self.fmts[trim(ext)] = trim(fmt)
+   end
+  end
+ end
+}
+
+
+-->8
+-- loader
+
+-- essay: `e` directive
+-- reads int16 char count,
+-- then parses that many bytes
+-- into a string (via chr).
+-- returns string, new read offset.
+function splubp_read_essay(addr)
+ local cs, n = {}, %addr
+ for a2 = addr+2, addr+n+1 do
+  add(cs, @a2)
+ end
+ return chr(unpack(cs)), addr+2+n
+end
+