[plt-scheme] units and rightward drift

You can use `include' to reduce it to zero. Or, you can define a new
language to reduce it to 2:

 (module foo-unit (lib "unit-lang.ss" "whereever")
   (import ...)
   (export ...)
   (define ...))

by redefining the #%module-begin macro in the unit-lang.ss file in the
whereever collection.

Robby

At Mon, 28 Apr 2003 23:46:26 -0400, "Neil W. Van Dyke" wrote:
>   For list-related administrative tasks:
>   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> 
> I tenaciously cling to the 79-columns rule of code formatting, so I'm
> interested in syntax for reducing rightward drift in unit definitions.
> 
> Currently, I do something like this, which results in a 6-space indent
> baseline for the definitions (assuming the popular indentation convention):
> 
>     |(module foo-unit mzscheme
>     |
>     |  (require (lib "unitsig.ss")
>     |           "foo-sig.ss")
>     |
>     |  (define foo@
>     |    (unit/sig foo^
>     |
>     |      (define (f1) ...
>     +----------------------------
>     |123456(
> 
> If adding "define-unit/sig" syntax were appropriate, the indent baseline
> is reduced to 4, which is a precious gain:
> 
>     |(module foo-unit mzscheme
>     |
>     |  (require (lib "unitsig.ss")
>     |           "foo-sig.ss")
>     |
>     |  (define-unit/sig foo@ foo^
>     |
>     |    (define (f1) ...
>     +----------------------------
>     |1234(
> 
> I'm guessing reducing it to 2 requires special support to be added to
> the MzScheme module loader, which is unfortunate:
> 
>     |(module/unit/sig foo-unit mzscheme foo@ foo^
>     |
>     |  (require (lib "unitsig.ss")
>     |           "foo-sig.ss")
>     |
>     |  (define (f1) ...
>     +----------------------------
>     |12(
> 
> I won't argue for reducing it to 0 (although it isn't entirely wacky,
> considering that the module loader seems to want exactly one "module"
> form per file, so the file constitutes a syntactic scope or extent):
> 
>     |(file-module/unit/sig foo-unit mzscheme foo@ foo^)
>     |
>     |(require (lib "unitsig.ss")
>     |         "foo-sig.ss")
>     |
>     |(define (f1) ...
>     +----------------------------
> 
> So... is "define-unit/sig" and/or "module/unit/sig" a good idea?
> 
> -- 
>                                              http://www.neilvandyke.org/
>