Sammich Compiler

local tArgs = {...}

if #tArgs<1 then
  printError("Usage: sammc <prgm>")
  return
end

if not fs.exists(tArgs[1]) or fs.isDir(tArgs[1]) then
  printError("Usage: sammc <prgm>")
  return
end

local funcs = {
  ["print"] = {
    1,
    {
      "print(",1,
    },
    ")",
  },
  ["store"] = {
    2,
    {
      "",1,
      " = ",2,
    },
    "",
  },
  ["concat"] = {
    2,
    {
      "",1,
      " = ",1,
      "..",2
    },
    "",
  },
  ["read"] = {
    1,
    {
      "",1,
      " = read()"
    },
    "",
  }
}

local inFile = fs.open(tArgs[1],"r")

function trim(s)
--  print(s)

  return s:match "^%s*(.-)%s*$",s:find("[^ ]")
end

local lineCount = 0
function parse(line)
  line = trim(line)
  for k,v in pairs(funcs) do
    if k==line then
      local fArgs = {}
      for i=1,v[1] do
        nxtLine = inFile.readLine()
        if not nxtLine then
          printError("Unexpected EOF:"..lineCount)
          error()
        end
        lineCount = lineCount+1
        local ln = trim(nxtLine)
        table.insert(fArgs,ln)
      end
      local endLine = ""
      local kk = 1
      repeat
        endLine = endLine..(v[2][kk] or "")
        endLine = endLine..(fArgs[v[2][kk+1]] or "")
        kk = kk+2
      until kk>#v[2]
      endLine = endLine..v[3]
      return endLine
    end
  end
end

local outStream = fs.open(tArgs[1]..".lua","w")

while true do
  line = inFile.readLine()
  lineCount = lineCount+1
  if not line then break end
  token = parse(line)
  print(token)
  outStream.write(token.."\n")
end

outStream.close()
inFile.close()