What are functions in Lua?

What are functions in Lua?

Functions are the main mechanism for abstraction of statements and expressions in Lua. Functions can both carry out a specific task (what is sometimes called procedure or subroutine in other languages) or compute and return values.

How do I trigger a function in Lua?

The API protocol to call a function is simple: First, you push the function to be called; second, you push the arguments to the call; then you use lua_pcall to do the actual call; finally, you pop the results from the stack.

What are Lua libraries?

A Lua library is a chunk that defines several Lua functions and stores them in appropriate places, typically as entries in a table. A C library for Lua mimics this behavior. Besides the definition of its C functions, it must also define a special function that corresponds to the main chunk of a Lua library.

What are parameters in Lua?

When a function is invoked, you pass a value to the argument. This value is referred to as the actual parameter or argument. The parameter list refers to the type, order, and number of the arguments of a method.

What does 3 dots mean in Lua?

The three dots ( ) in the parameter list indicate that the function has a variable number of arguments. When this function is called, all its arguments are collected in a single table, which the function accesses as a hidden parameter named arg .

What are the helper functions in cmano Lua?

There are two main files in this repo: Helper functions ( cmano_helpers.lua) – These are intended to be added to the scenario and defined when the scenario loads. These fuctions are actually used in scenario Action and Condition Lua scripts used in Events.

How to define a function in Lua programming language?

Lua – Functions 1 Defining a Function. A method definition in Lua programming language consists of a method header and a method body. 2 Example. Following is the source code for a function called max (). 3 Function Arguments. 4 Calling a Function. 5 Assigning and Passing Functions. 6 Function with Variable Argument.

What does pcall do when there is an error in Lua?

The pcall (f, arg1.) function calls the requested function in protected mode. If some error occurs in function f, it does not throw an error. It just returns the status of error.

When to use assert and error in Lua?

This is a runtime error, which had occurred due to not passing two variables. The b parameter is expected and here it is nil and produces an error. In order to handle errors, we often use two functions − assert and error.

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