load
Lua function

load

Summary

Loads a chunk by calling a function repeatedly

Prototype

f = load (loader, debugname)


Description

Loads a chunk using function f to get its pieces. Each call to f must return a string that concatenates with previous results. A return of nil (or no value) signals the end of the chunk.

If there are no errors, returns the compiled chunk as a function; otherwise, returns nil plus the error message. The environment of the returned function is the global environment.

This could be used to gradually build up a chunk (for example from a network), or to write a preprocessor that reads in a file, preprocess it (like the C preprocessor) and returns the altered code to the Lua interpreter.

The example below shows generating code from entries in a table.


function getcode (t)
local pos = 0
  local function iterator (s)
    pos = pos + 1
    return t [pos]
  end -- iterator
  return iterator
end -- getcode


code = {
  "local a = 1 ",
  "print ('a =', a) ",
  "print 'done.'"
  }
  
assert (load (getcode (code))) ()


See Also ...

Topics

DOC_lua_base Lua base functions
DOC_lua_bc Lua bc (big number) functions
DOC_lua_bit Lua bit manipulation functions
DOC_lua_coroutines Lua coroutine functions
DOC_lua_debug Lua debug functions
DOC_lua_io Lua io functions
DOC_lua_math Lua math functions
DOC_lua_os Lua os functions
DOC_lua_package Lua package functions
DOC_lua_rex Lua PCRE regular expression functions
DOC_lua Lua script extensions
DOC_lua_string Lua string functions
DOC_lua_tables Lua table functions
DOC_lua_utils Lua utilities
DOC_scripting Scripting

Lua functions

LUA_assert assert (Asserts that condition is not nil and not false)
LUA_collectgarbage collectgarbage (Collects garbage)
LUA_dofile dofile (Executes a Lua file)
LUA_error error (Raises an error message)
LUA_gcinfo gcinfo (Returns amount of dynamic memory in use)
LUA_getfenv getfenv (Returns the current environment table)
LUA_getmetatable getmetatable (Returns the metatable for the object)
LUA_ipairs ipairs (Iterates over a numerically keyed table)
LUA_loadfile loadfile (Loads a Lua file and parses it)
LUA_loadlib loadlib (Loads a DLL (obsolete in Lua 5.1))
LUA_loadstring loadstring (Compiles a string of Lua code)
LUA_module module (Creates a Lua module)
LUA_next next (Returns next key / value pair in a table)
LUA_pairs pairs (Traverse all items in a table)
LUA_pcall pcall (Calls a function in protected mode)
LUA_print print (Prints its arguments)
LUA_rawequal rawequal (Compares two values for equality without invoking metamethods)
LUA_rawget rawget (Gets the value of a table item without invoking metamethods)
LUA_rawset rawset (Sets the value of a table item without invoking metamethods)
LUA_require require (Loads a module)
LUA_select select (Returns items in a list)
LUA_setfenv setfenv (Sets a function's environment)
LUA_setmetatable setmetatable (Sets the metatable for a table)
LUA_tonumber tonumber (Converts a string (of the given base) to a number)
LUA_tostring tostring (Converts its argument to a string)
LUA_type type (Returns the type of a variable)
LUA_unpack unpack (Unpacks a table into individual items)
LUA_xpcall xpcall (Calls a function with a custom error handler)

(Help topic: lua=load)

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