6 Commits
main ... splubp

264
splubp.p8 Normal file
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pico-8 cartridge // http://www.pico-8.com
version 42
__lua__
-- splubp data transport
-- by kistaro windrider
-- shrinko-8 hints
DEBUG = true --[[const]]
-- >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 trim(s)
local f, e = 1, #s
while (f <= e and s[f]==" ") f += 1
while (e >= f and s[e]==" ") e -= 1
if (f<e) return sub(s,f,e)
return ""
end
function shatter(s)
local ret ={}
for line in all(split(s, "\n")) do
local row = {}
for cell in all(split(split(line, "--")[1], " ")) do
cell = trim(cell)
if (#cell > 0) add(row, cell)
end
if (#row > 0) add(ret, row)
end
return ret
end
function crush(s)
ret = ""
for line in shatter(s) do
for tok in line do
ret..=tok.." "
end
ret = sub(ret, 1, -2).."\n"
end
if (#ret > 0) return sub(ret, 1, -2)
return ""
end
-- >8
-- common
--[[preserve-keys]] splubp = mknew{
ptr = 0x8000,
init = function(self)
-- fill from ffile or saved file
self.fmts = {}
if (not self.ffile) self.ffile, self.ptr = self:e()
for f in all(split(self.ffile, "===", false)) do
local tok = shatter(f)
if DEBUG then
assert(#tok > 1, "not enough rows in "..tostr(tok))
assert(#tok[1] == 1, "bad extension row: "..tostr(tok[1]))
end
self.fmts[deli(tok, 1)[1]] = tok
end
end,
}
function splubp:ppi(n)
self.ptr += n
return self.ptr - n
end
function splubp:op()
self.cri += 1
return self.row[self.cri]
end
function splubp:c(n)
n = n or 1
return peek(self:ppi(n), n)
end
function splubp:i()
return %self:ppi(2)
end
function splubp:n()
return $self:ppi(4)
end
function splubp:e()
return chr(self:c(self:i()))
end
-- >8
-- writer
function splubp:emit_fmts()
self:write_e(self.ffile)
end
-- execute next op (write data)
function splubp:wnx(...)
return self["write_"..self:op()](self, ...)
end
-- write an object of a known type.
-- item must have a field named
-- _file, containing a filename
-- with a correct extension
-- to save the file under.
function splubp:emit_item(obj)
if DEBUG then
--[[global]] splubp_last_emit = obj
end
-- todo: should _addr skip the
-- filename, instead?
obj._addr = self.ptr
self:write_s(obj._file)
for row in all(self.fmts[split(filename, ".")[2]]) do
local alt = self.wdirectives[row[1]]
if alt then
alt(self, obj, row)
else
self:write_fmt(obj[row[1]], row, 2)
end
end
end
-- TODO: splubp.wdirectives -- a
-- table mapping non-key
-- special values to
-- functions to write them
-- TODO: write_fmt: recursive
-- writing thing
-- Write each argument as one
-- byte at self.ptr, then
-- increment self.ptr by the
-- number of bytes written.
function splubp:write_c(...)
poke(self:ppi(#{...}), ...)
end
-- Like etch but it takes only
-- a single 2-byte int.
function splubp:write_i(i)
poke2(self:ppi(2), i)
end
-- Like etch but it takes only
-- a single 4-byte number.
function splubp:write_n(n)
poke4(self:ppi(4), n)
end
function splubp:write_s(s)
self:write_c(#s, ord(s, 1, #s))
end
function splubp:write_e(s)
self:write_i(#s)
self:write_c(ord(s,1,#s))
end
splubp.write_b = splubp.write_c
function splubp:write_shr(n)
n <<= self:op()
self:wnx(n)
end
function splubp:write_a(tbl)
if (DEBUG) assert(#tbl <= 255, "'a' can't write array of length "..#tbl)
self:write_c(#tbl)
local rpt = self.cri
for item in all(tbl) do
self.cri = rpt
self:wnx(item)
end
end
function splubp:write_t(tbl)
if DEBUG then
local want_len = self.row[self.cri]
assert(#tbl == want_len, "'t' wants "..tostr(want_len).." items, but got "..#tbl..": "..tostr(tbl))
end
for i=1,self:op() do
self:wnx(tbl[i])
end
end
-->8
-- loader
-- execute next op (read)
function splubp:rnx()
return self[self:op()](self)
end
function splubp:s()
return chr(self:c(self:c()))
end
function splubp:b()
local ret = self:c()
if (ret < 128) return ret
return ret-256
end
function splubp:shr()
local amt = self:op()
return self:rnx() >>> amt
end
function splubp:a()
local ret,rpt = {},self.cri
for i = 1,self:c() do
self.cri=rpt
add(ret, self:rnx())
end
return ret
end
function splubp:t()
local ret = {}
for i=1,self:op() do
add(ret, self:rnx())
end
return ret
end