Railroad Diagram Generator: A tool for creating syntax diagrams

bottlecaps.de

55 points·ingve··9 comments

One of my favorite tools generates these for regexes, taking much of they mystery out of the syntax:

Railroad Diagrams are used to great effect in SQLite documentation, for description of mandatory/optional syntax elements, for example:

However the SQLite project seems to be using different tool, implemented in Tcl: http://wiki.tcl-lang.org/21708 .

Oracle uses such diagrams for many years.

Pascal was described with such diagrams in Wirth's Pascal User Manual 1975 and they were not new then.

They made learning Pascal much easier than trying to interpret BNF.

saw it on the json page as well

but I'm not into grammars. I used antlr once, and they did support that as well in the designer http://www.antlr3.org/works/screenshots/ambiguouspath.jpg

Does not involve railroads :/

That said, it seems to work well and produce nice graphics, so functionality is a win.

>Does not involve railroads :/

Couldn't tell if you were joking but "railroad" is a common term-of-art for syntax diagrams. Example: https://en.wikipedia.org/wiki/Syntax_diagram

Never heard them called that, and so I clicked the link with different expectations ;)