Re: [Caml-list] Literate (sort-of) programming in OCaml

["Raphaël Proust" <raphlalou@gmail.com>]

On Mon, Sep 2, 2013 at 5:39 PM, Jonathan Protzenko
<jonathan.protzenko@gmail.com> wrote:
> I am currently writing a big, mostly textual document in format blah
> (blah being of a course a meta-variable). Are there any tools that
> would allow me to interleave OCaml code with the contents of my
> document?
>
> More on my use-case. Creating this document requires me to perform
> various subtasks, such as:
> - write a code snippet in the document,
> - put the code snippet in a file,
> - call an external program on the file,
> - paste the output into the document.

Current workflow I use involves:
- mkfile: a rule file for mk (Plan9's take on make, it has simple
escaping and a readable man page) to drive the whole thing,
- bar: a compiler for the language bar that includes a Latex pretty
printing mode
- inc/: a directory where I place all my code samples from language bar
- main.pdc: a pandoc file holding the source.

Extracts from the mkfile:
~~~~~~~
TARGET=main.pdf
SOURCE=${TARGET:%.pdf=%.pdc}

INCLUDES=`{cat $SOURCE | grep '\\input{.*\.tex}' | sed
's/^.*\\input{([^\$\\}]*\.tex)}.*$/\1/'}

$TARGET: $SOURCE $INCLUDES
        pandoc -o $TARGET $SOURCE

%.pp.tex: %.bar bar.byte
        OCAMLRUNPARAM=$OCAMLRUNOPT ./bar.byte -latex $stem.bar > $target

%.pp.annot.tex: %.bar bar.byte
        OCAMLRUNPARAM=$OCAMLRUNOPT ./bar.byte -latex -annot $stem.bar > $target
~~~~~~~

Extracts from bar.mli:
~~~~~~~
module type PRINTER = sig
  val t: annotations:bool -> t -> string
end
module LatexPP : PRINTER
~~~~~~~

Extracts from the main.pdc
~~~~~~~
The annotation process, blahblah. Thus the program $\input{inc/foo.pp.tex}$
is annotated in the following way: $\input{inc/foo.pp.annot.tex}$
~~~~~~~


Known bugs and shortcomings:
- sed works line-wise so the mkfile INCLUDES variable is not set
properly when there are several \input on the same line.
- the passing of argument (using two rules with and two file
extensions) is hackish and would not scale.


Less painful than copy-pasting things and easier to keep everything in
sync. It's also nice to be able to do things such as:
\begin{align*}
<some math>\input{inc/function-application.pp.tex}<more math>\\
<more math>\input{inc/function-declaration.pp.tex}<more math>\\
<more math>\input{inc/if-then-else.pp.tex}<more math>\\
<etc.>
\end{align*}

-- 
______________
Raphaël Proust