28 – User-Defined Types in C. In the previous chapter, we saw how to extend Lua with new functions written in C. Now, we will see how to extend Lua with new types written in C. We will start with a small example that we will extend through the chapter with metamethods and other goodies. Our example is a quite simple type: numeric arrays.

A library to convert Lua values to and from C structs

This library offers basic facilities to convert Lua values to and
from C structs. Its main functions are struct.pack, which packs
multiple Lua values into a struct-like string; and struct.unpack,
which unpacks multiple Lua values from a given struct-like string.
Dns 323 application pack download.

Lua dissectors¶. The code below shows what the code for the Lua dissector, displayed in packet 1 in Figure 1, looks like.The Proto variable defines a new protocol. In this example, a dissector for the internalsnd struct, called internalsnd, is created.
$ luarocks install struct. This library offers basic facilities to convert Lua values to. Its main functions are struct.pack, which packs. Multiple Lua values into a struct-like string; and struct.unpack, which unpacks multiple Lua values from a given struct-like string.
Template struct isluaprimitive; template struct isproxyprimitive; This trait is used by proxy to know which types should be returned as references to internal Lua memory (e.g., userdata types) and which ones to return as values (strings, numbers, references).
Using user defined types (“usertype”s, or just “udt”s) is simple with sol. If you don’t call any member variables or functions, then you don’t even have to ‘register’ the usertype at all: just pass it through. But if you want variables and functions on your usertype inside of Lua, you need to register it.

Versions

1.2-27 years ago866 downloads

Dependencies

lua >= 5.1

Dependency for

dbf, kong-ip-location, lua-pb, lua-resty-ntlm, lua-websockets, lua-websockets-core, lua-xlsxwriter, lunary, lunary, lyre, OiL, lua-xlsxwriter, ZipWriter, ZipWriter

Manifests

This first edition was written for Lua 5.0. While still largely relevant for later versions, there are some differences.
The fourth edition targets Lua 5.3 and is available at Amazon and other bookstores.
By buying the book, you also help to support the Lua project.

Programming in Lua

Part II. Tables and ObjectsChapter 11. Data Structures

Lua Struct Codes

Tables in Lua are not a data structure;they are the data structure.All structures that other languages offer---arrays,records, lists, queues, sets---arerepresented with tables in Lua.More to the point,tables implement all these structures efficiently.

In traditional languages, such as C and Pascal,we implement most data structures with arrays and lists(where lists = records + pointers).Although we can implement arrays and lists usingLua tables (and sometimes we do that),tables are more powerful than arrays and lists;many algorithms are simplified to the point of triviality withthe use of tables.For instance, you seldom write a search in Lua,because tables offer direct access to any type.

It takes a while to learn how to use tables efficiently.Here, we will show how you can implementtypical data structures with tablesand will provide some examples of their use.We will start with arrays and lists,not because we need them for the other structures,but because most programmers are already familiar with them.We have already seen the basics of this material in ourchapters about the language,but I will repeat it here for completeness.

Versions

Dependencies

Dependency for

Manifests

Lua Struct Codes

Lua Ffi C Struct