mirror of
https://github.com/Jermolene/TiddlyWiki5
synced 2024-12-04 23:39:57 +00:00
cd362c78c3
* [Docs] Simplify the Railroad Plugin tiddler * Update Railroad Diagrams.tid * Update Railroad Plugin.tid
21 lines
1.1 KiB
Plaintext
21 lines
1.1 KiB
Plaintext
created: 20150105133800000
|
|
modified: 20211117212441252
|
|
tags: Concepts
|
|
title: Railroad Diagrams
|
|
|
|
<<.def "Railroad diagrams">>, sometimes called <<.def "syntax diagrams">>, are a visual way of explaining the syntax rules of a computer language. Reading one is like reading a public transport map.
|
|
|
|
Each diagram starts on the left and ends on the right. Simply follow any line from the startpoint to the endpoint. All the alternative lines are equally valid. A line will sometimes jump over an item that is optional, or loop back to indicate that an item can be repeated.
|
|
|
|
<$railroad text="""
|
|
start [:optional] {repeated +","} end
|
|
"""/>
|
|
|
|
In the example above, a comma appears between each occurrence of the `repeated` item. The comma path runs from right to left, and can only be reached by first passing through `repeated`.
|
|
|
|
Characters in round boxes are literal, i.e. they denote themselves. A name in a rectangular box denotes a further railroad diagram.
|
|
|
|
The TW [[Filter Syntax]] documentation makes extensive use of railroad diagrams.
|
|
|
|
The railroad diagrams in ~TiddlyWiki's documentation are generated with the [[Railroad Plugin]].
|