Literate Programming Examples from my Website

I love literate programming, which I find a very interesting and elegant approach. Literate programming was first proposed by Donald Knuth and it is supported very well by Emacs: consult the Org Mode manual for more information.

This page lists the pages of this website which use literate programming.

First of all, we find all occurrences of #+BEGIN_SRC in the source files (with the exception of this file) which are required to produce results. We use sed to process the output, using a TAB to separate the filename from the content and by extracting the programming language, which is the first word after #+BEGIN_SRC.

grep BEGIN_SRC \
     $(find ../.. -name "*.org" -a \! -name literate-programming-references.org ) | \
    grep results | grep -v "_site" | sed 's/:/\t/' | \
    sed -E 's/#\+BEGIN_SRC +([^ ]+) .*/\1/' 

The output, which is not exported in the HTML page, looks like:

| ../../bookstream.org                                    | ruby    |
| ../../notes/covid/new-cases.org                         | R       |
| ../../notes/covid/new-cases.org                         | ruby    |

We now use datamash to make the data into a Pivot table, with the crosstab command. Sed is used to generate links to the files, by prepending file: to the filenames and to remove the “N/A” entries.

echo "$table" | sort | datamash crosstab 1,2 | sed 's-N/A--'g | sed -E 's/\.\./file:../'