enter image description here

I'd also want to know how can I draw them.


3 Answers 3


That looks like SQLite's syntax diagrams.

Their FAQ says:

How are the syntax diagrams (a.k.a. "railroad" diagrams) for SQLite generated?

The answer is a link to this wiki page on "Generating Syntax Diagrams Using Tk".

The wiki links to this Tcl source code for generating the diagrams.


That is a syntax diagram. I think I first saw them in Grogono's "Programming in Pascal", from 1980, but they were used in Wirth's 1973 report on PASCAL.


Just a hint for LaTeX-Users:

The rail-package allows the generation of such rail-diagramms with (La)TeX.

You may check TeX.SX for an example.

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