#define private public - Claus Brod on stuff (01 May 2007)

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---+++ [[DefinePrivatePublic20070501]["Macro" considered harmful]] (01 May 2007)

<summary>
In the [[OneSpaceModeling.WebHome][<nop>OneSpace Modeling FAQ]] pages, I sometimes
used or still use the term "macro" for the code snippets which I present there.
Not a wise choice, as it occurred to me a while ago, and I intend to fix that
now, or at least over time as I revisit those pages for other updates.
</summary>

I used "macro" mostly for historical reasons. "Macro" is an overloaded 
term which can mean (too) many things:
   * In Lisp, a macro is a piece of code defined by
     [[http://www.lisp.org/HyperSpec/Body/mac_defmacro.html][defmacro]]. Macros
     in Lisp are a clever way to extend the language. If you want to
     learn more about this (or about Common Lisp in general, in fact), I recommend 
     Peter Seibel's "Practical Common Lisp" - here's 
     [[http://www.gigamonkeys.com/book/macros-defining-your-own.html][the section on macros]].
   * <nop>CoCreate's 2D package, <nop>OneSpace Drafting, has a built-in macro
     interpreter which can be used to customize and extend the product. Since many
     <nop>OneSpace Drafting migrate from 2D to 3D, i.e. to <nop>OneSpace Modeling,
     they tend to take their nomenclature with them, and so they often call
     pieces of Lisp customization code a "macro", too.
   * In many software packages, users can record the interaction with the product
     and save the result into files, which are then often called macro files.
     <nop>OneSpace Modeling's recorder is such a mechanism, and so using
     the word "macro" is kind of natural for many users.

And so many users of <nop>OneSpace Modeling call their Lisp functions and 
customizations "macros", although this isn't really the correct term. Well, 
at least in most cases. Many of those customizations use an API called
=sd-defdialog= which is provided by the "Integration Kit" library which
ships with <nop>OneSpace Modeling. This API is, in fact, implemented
using =defmacro=, i.e. =sd-defdialog= is itself a Lisp macro. So if a user
writes code which builds on =sd-defdialog= and then calls the result a macro,
he's actually not _that_ far from the truth - although, of course, still
incorrect.

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