-- miniforth3.lua - 2007mar25, Edrx
-- For Lua-5.1 (because of string.match)
-- This is part of blogme3
-- http://anggtwu.net/miniforth/miniforth3.lua.html
-- http://anggtwu.net/miniforth/miniforth3.abs.txt.html

-- pat has one "real" capture and then an empty capture
parsebypattern = function (pat)
    local capture, newpos = string.match(subj, pat, pos)
    if newpos then pos = newpos; return capture end
  end

parsespaces     = function () return parsebypattern("^([ \t]*)()") end
parseword       = function () return parsebypattern("^([^ \t\n]+)()") end
parsenewline    = function () return parsebypattern("^(\n)()") end
parserestofline = function () return parsebypattern("^([^\n]*)()") end

getword          = function () parsespaces(); return parseword() end
getwordornewline = function ()
    parsespaces()
    return parseword() or parsenewline()
  end

_F = {}
_F["%L"] = function () assert(loadstring(parserestofline()))() end
_F["\n"] = function () end

outer = function ()
    word = getwordornewline()
    if not word then return nil end       -- EOF -> word=nil -> break
    if _F[word] then _F[word](); return true end
    error(string.format("Unrecognized word: %q", word))
  end
outerloop = function () if outer() then outerloop() end end

readfile = function (fname)
    local f = assert(io.open(fname, "r"))
    local fcontents = f:read("*a"); f:close(); return fcontents
  end
setsubjto = function (str) subj = str; pos = 1 end
runstring = function (str) setsubjto(str); outerloop() end
runfile   = function (fname) runstring(readfile(fname)) end
-- runfile(arg[1])

-- subj = readfile(arg[1])
-- pos = 1
-- outerloop()