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GNU Guix consists of Scheme code that implements the deployment model
of the Nix package management tool.  In fact, it currently talks to a
build daemon whose code comes from Nix (see the manual for details.)

Nix was initially written by Eelco Dolstra; other people have been
contributing to it.  See `nix/AUTHORS' for details.

The list of GNU Guix contributors is now generated from the output of
'git log' and written to this file, as can be seen in release tarballs.
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es/>. (define-module (gnu installer timezone) #:use-module (gnu installer utils) #:use-module (guix i18n) #:use-module (srfi srfi-1) #:use-module (srfi srfi-26) #:use-module (srfi srfi-34) #:use-module (srfi srfi-35) #:use-module (ice-9 match) #:use-module (ice-9 receive) #:export (locate-children timezone->posix-tz timezone-has-child? zonetab->timezone-tree posix-tz->configuration)) (define %not-blank (char-set-complement char-set:blank)) (define (posix-tz->timezone tz) "Convert given TZ in Posix format like \"Europe/Paris\" into a list like (\"Europe\" \"Paris\")." (string-split tz #\/)) (define (timezone->posix-tz timezone) "Convert given TIMEZONE like (\"Europe\" \"Paris\") into a Posix timezone like \"Europe/Paris\"." (string-join timezone "/")) (define (zonetab->timezones zonetab) "Parse ZONETAB file and return the corresponding list of timezones." (define (zonetab-line->posix-tz line) (let ((tokens (string-tokenize line %not-blank))) (match tokens ((code coordinates tz _ ...) tz)))) (call-with-input-file zonetab (lambda (port) (let* ((lines (read-lines port)) ;; Filter comment lines starting with '#' character. (tz-lines (filter (lambda (line) (not (eq? (string-ref line 0) #\#))) lines))) (map (lambda (line) (posix-tz->timezone (zonetab-line->posix-tz line))) tz-lines))))) (define (timezones->timezone-tree timezones) "Convert the list of timezones, TIMEZONES into a tree under the form: (\"America\" (\"North_Dakota\" \"New_Salem\" \"Center\")) representing America/North_Dakota/New_Salem and America/North_Dakota/Center timezones." (define (remove-first lists) "Remove the first element of every sublists in the argument LISTS." (map (lambda (list) (if (null? list) list (cdr list))) lists)) (let loop ((cur-timezones timezones)) (match cur-timezones (() '()) (((region . rest-region) . rest-timezones) (if (null? rest-region) (cons (list region) (loop rest-timezones)) (receive (same-region other-region) (partition (lambda (timezone) (string=? (car timezone) region)) cur-timezones) (acons region (loop (remove-first same-region)) (loop other-region)))))))) (define (locate-children tree path) "Return the children of the timezone indicated by PATH in the given TREE. Raise a condition if the PATH could not be found." (let ((extract-proc (cut map car <>))) (match path (() (sort (extract-proc tree) string<?)) ((region . rest) (or (and=> (assoc-ref tree region) (cut locate-children <> rest)) (raise (condition (&message (message (format #f (G_ "Unable to locate path: ~a.") path)))))))))) (define (timezone-has-child? tree timezone) "Return #t if the given TIMEZONE any child in TREE and #f otherwise." (not (null? (locate-children tree timezone)))) (define* (zonetab->timezone-tree zonetab) "Return the timezone tree corresponding to the given ZONETAB file." (timezones->timezone-tree (zonetab->timezones zonetab))) ;;; ;;; Configuration formatter. ;;; (define (posix-tz->configuration timezone) "Return the configuration field for TIMEZONE." `((timezone ,timezone)))
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