Re: Data Dictionary and Configuration Files with Guile Scheme

[Romel Sandoval <romel@lavabit.com>]

Thanks Thien-Thi that's exactly what I was trying to achieve.

El mié, 18-08-2010 a las 20:20 +0200, Thien-Thi Nguyen escribió:
> () Romel Sandoval <romel@lavabit.com>
> () Thu, 05 Aug 2010 12:15:44 -0500
> 
>    What do you think?
> 
> I use Guile-PG (several modules) and a homegrown metainfo table
> accessible via ‘(ttn-do zzz various-db) personal-pgtable-defs’ et al:
> http://www.gnuvola.org/software/ttn-do/ttn-do.html.gz#zzz-various_002ddb
> 
> Here is ~/.pgtable-defs, omitting some parts:
> 
>   ;;; ~/.pgtable-defs --- database descriptions -*- scheme -*-
>   
>   ;; Keyword Expansions
>   ;; ------------------
>   
>   ((#:pk "PRIMARY KEY")
>    (#:u  "UNIQUE")
>    (#:nn "NOT NULL")
>    (#:mf "MATCH FULL")
>    (#:dc "ON DELETE CASCADE")
>    (#:uc "ON UPDATE CASCADE")
>    (#:r  "REFERENCES")
>    (#:tz "WITH TIME ZONE"))
>   
>   ;; Database Table Definitions
>   ;; --------------------------
>   ;;
>   ;; ((DB-1 (TABLE DEF ...) (TABLE DEF ...) ...)
>   ;;  (DB-2 (TABLE DEF ...) (TABLE DEF ...) ...) ...)
>   ;;
>   ;; Some day `infer-defs' will be able to round-trip these...
>   
>   (("ttn"
>   
>     ("sw_maint"
>      (v    bool #:nn)
>      (url  text #:nn)
>      (mon  text #:nn)
>      (name text #:pk)
>      (orig text)
>      (mtim timestamp[])))                 ; 0: mon
>   
>    ("gnuvola"
>   
>     ("updbad"
>      (time     timestamp #:pk)
>      (cause    text)
>      (errmsg   text))
>   
>     ("updok"
>      (time     timestamp #:pk)
>      (wrote    int4)
>      (read     int4)
>      (rate     float4)
>      (total    int4)
>      (speedup  float4))
>   
>     ("updfiles"
>      (file     text)
>      (move     char)
>      (time     timestamp #:r "updok" #:dc #:uc))))
>   
>   ;;; ~/.pgtable-defs ends here
> 
> This file consists of two forms.  The first is (hopefully)
> self-explanatory.  The second describes two databases:
> 
>   db       tables
>   -------  -----------------------
>   ttn      sw_maint
>   gnuvola  updbad, updok, updfiles
> 
> Each table's columns are further described in a way that really ought to
> be queryable from the backend, so that is a Code Enhancement Opportunity
> for the Guile-PG reflection module alluded to by the "Some day" comment.
> 
> Although i think SQL is ugly (and thus concur in jest, i believe,
> with Andy Wingo's admonition :-), Guile-PG makes it livable.  E.g.:
> http://www.gnuvola.org/software/guile-pg/qcons-notes.txt
> 
> So, to answer your question: yes, sexps work fine as a Data Dictionary.