Re: [Chicken-users] INI files in Scheme? (or something similar)

[Mario Domenech Goulart]

Hi Hans,

On Mon, 03 Mar 2008 20:22:11 -0500 Hans Nowak <address@hidden> wrote:

> Is there a "standard" way to do INI files (or similar kinds of
> initialization files, ala .bashrc etc) in Scheme?  For example,
> something like this:
> 
> [config.ini]
> --->8---
> [Keys]
> Developer=INSERT_DEV_ID
> Application=INSERT_APP_ID
> Certificate=INSERT_CERT_ID
> 
> [Server]
> ; This is for the development sandbox
> URL=api.sandbox.foobar.com
> Directory=/ws/api.dll
> 
> [Authentication]
> ; blah blah blah
> Token=INSERT_USER_TOKEN
> --->8---
> 
> 
> I understand that this could easily be done in Scheme itself, e.g.
> 
> (define developer INSERT_DEV_ID)
> (define url "api.sandbox.foobar.com")

Another approach would be translating the .ini syntax to Scheme, and
having a program to read the conf file as a list:

,----[ config.ini ]
| (keys
|  (developer "INSERT_DEV_ID")
|  (application "INSERT_APP_ID")
|  (certificate "INSERT_CERT_ID"))
| 
| (server
|  (url "api.sandbox.foobar.com")
|  (directory "/ws/api.dll"))
| 
| (authentication
|  (token "INSERT_USER_TOKEN"))
`----

,----[ config-reader.scm ]
| (define conf-file "config.ini")
| 
| (define read-conf
|   (let ((data #f))
|     (lambda ()
|       (unless data
|         (set! data (with-input-from-file conf-file read-file)))
|       data)))
| 
| (define (conf-section section)
|   (alist-ref section (read-conf)))
| 
| (define (conf-item section item #!optional default)
|   (cond ((alist-ref item (conf-section section))
|          => (lambda (i) (car i)))
|         (else default)))
|   
| (print (conf-item 'server 'url))
`----

Or using parameters:

,----[ config.ini ]
| (conf:keys-application "something")
`----

,----[ config-reader.scm ]
| (define conf-file "config.ini")
| (define conf:keys-developer (make-parameter "INSERT_DEV_ID"))
| (define conf:keys-application (make-parameter "INSERT_APP_ID"))
| ;; ... other defaults here
| 
| (load conf-file)
| 
| (print (conf:keys-application))
`----


Of course, there are many other ways.

Best wishes,
Mario