created: 20221007124007426
modified: 20240310173130052
tags: Concepts Reference
title: Procedures
type: text/vnd.tiddlywiki

!! Introduction

<<.from-version "5.3.0">> A <<.def procedure>> is a named snippet of text. They are typically defined with the [[Pragma: \procedure]]:

```
\procedure my-procedure(parameter:"Default value")
This is the procedure, and the parameter is <<parameter>>.
\end
```

The name wrapped in double angled [[brackets|Brackets]] is used a shorthand way of [[transcluding|Transclusion]] the snippet. Each of these <<.def "procedure calls">> can supply a different set of parameters:

```
<<my-procedure>>
<<my-procedure parameter:"The parameter">>
```

The parameters that are specified in the procedure call are made available as variables.

<<.tip """If a procedure has more than 1 parameter, it is highly encouraged to use "named parameters", as shown in the second example above. Even if it is more to type, it will pay off in the long run.""">>

!! How Procedures Work

Procedures are implemented as a special kind of [[variable|Variables]]. The only thing that distinguishes them from ordinary variables is the way that the parameters are handled.

!! Using Procedures

* [[Procedure Definitions]] describes how to create procedures
* [[Procedure Calls]] describes how to use procedures
* [[Procedure Parameter Handling]] describes how procedure parameters work
* [[Procedure Syntax]] is a formal syntax description using railroad diagrams