How a load reader can pre-parse chunks?

[Varanda <m@...>]

Hello All,

I am implementing a Lua shell using load function.

It is working fine for single line entries. I would like to add multiline support WITHOUT adding a explicit multi-line line terminator (like ‘\’ in C and makefiles)

Question: Is there a parser that the reader can use to figure out when the chunk is completed?

For example, what could be done inside the following “chunk_reader” for detecting it?

Or should the load caller keep calling it based on “<eof>” presence in the error message?

Thanks in advance,

Varanda

 

idx = 1

-- complete chunk:

test_chunck1 = {

  "print(\"result of 1 == 1:\")\n",

  "if 1 == 1 then \n",

  "print(\"  true\")\n",

  "else print(\"  false\")\n",

  "end",

  "print(\"All Done\")\n",

  "end\n"

}

-- incomplete chunk

test_chunck2 = {

  "print(\"result of 1 == 1:\")\n",

  "if 1 == 1 then \n"

}

selected_chunk = test_chunck1

function chunck_reader()

  if idx > #selected_chunk then

    return nil

  end

  local ret = selected_chunk[idx]

  idx = idx + 1

  return ret

end

  

function test_load()

  local f,msg = load(chunck_reader)

  if f ~= nil then

    f()

  else

    print("error: " .. msg)

  end

end

print("load a complete chunk:")

selected_chunk = test_chunck1

idx = 1

test_load()

print("load an incomplete chunk:")

selected_chunk = test_chunck2

idx = 1

test_load()