This page describes how to submit a piece of code that corrects or extends the Axiom project.

In general a patch file is of the form:

    cd the.dir
    diff -Naur file.pamphlet file.pamphlet.new >the.dir.file.pamphlet.patch

This has the following features:

• it tells where the patch is being applied
• the -Naur options gives context
• the impact of a change to multiple files become visible

If you don't like to keep the old version of files around, you can use one of the following instead:

    svn diff --diff-cmd /usr/bin/diff -x -Naur file.pamphlet >the.dir.file.pamphlet.patch

    tla diff -D -Naur file.pamphlet >the.dir.file.pamphlet.patch

    cvs diff -NauR file.pamphlet >the.dir.file.pamphlet.patch

This assumes that you are using CVS, Subversion or GNU Arch 1.3.4 or later.

In case you want to do that with several files (recursively down a directory) at once:

    cd $AxiomSilver
    svn diff --diff-cmd /usr/bin/diff -x -Naur > silver.patch

Finally, send the patch to the axiom-developer mailing list.

Tim Daly reads the patches before applying them, so be sure to document the reasons for the change in the pamphlet file. It may seem trivial but remember that I didn't do the initial analysis so he, and others, will have to understand after the fact.

In most cases in a pamphlet file if you're changing a few lines of code or a whole function it should be documented thus:

    ...
    (defun foo ()
      (list
        "this is ok code"
        "this is broken code"
        "this is also broken"
        "this is ok"
      ))

turns into:

    \subsection{foo list fix}
    This code used to read:
    \begin{verbatim}
        "this is broken code"
        "this is also broken"
    \end{verbatim}
    but clearly the elements of the list are wrong. We are going to
    print this list for the user so we don't want them to know anything
    is broken. Thus we have wonderful new code that will inspire confidence.
    This list is printed with the [[printlist]] function.
    <<foo list fix>>=
    "this is great code"
    "this inspires confidence"
    @
    ...
    (defun foo ()
      (list
        "this is ok code"
        <<foo list fix>>
        "this is ok"
      ))

and, yes, that this is tedious.

In general, it is also useful to update the pamphlet files with documentation-only changes as you understand what a block of code is intended to do. Most of this information has been lost to history and the world can leverage your efforts at understanding if you take the time to document it. In many ways this is as important as fixing the code.

PS: We will soon have another way to submit patches, since any modification should first go into the silver branch and survive public review, but the need to document properly will not be modified.