From 5097e30babe31a40a3fb8e281fee2a472414e5f8 Mon Sep 17 00:00:00 2001 From: Mathieu Lirzin Date: Wed, 20 Apr 2016 04:31:52 +0200 Subject: job-specifier: Add '%find-best-next' procedure. * scm/mcron/job-specifier.scm (find-best-next): Rename to ... (%find-best-next): ... this. Rewrite it using a functional style. All callers changed. --- scm/mcron/job-specifier.scm | 50 +++++++++++++++++++-------------------------- 1 file changed, 21 insertions(+), 29 deletions(-) (limited to 'scm/mcron/job-specifier.scm') diff --git a/scm/mcron/job-specifier.scm b/scm/mcron/job-specifier.scm index 3f73b82..1c2f9d9 100644 --- a/scm/mcron/job-specifier.scm +++ b/scm/mcron/job-specifier.scm @@ -24,6 +24,13 @@ ;; add-job function), and the procedure for declaring environment modifications. (define-module (mcron job-specifier) + #:use-module (ice-9 match) + #:use-module (mcron core) + #:use-module (mcron environment) + #:use-module (mcron vixie-time) + #:use-module (srfi srfi-1) + #:use-module (srfi srfi-26) + #:re-export (append-environment-mods) #:export (range next-year-from next-year next-month-from next-month @@ -33,15 +40,7 @@ next-second-from next-second set-configuration-user set-configuration-time - job - find-best-next) - #:use-module (mcron core) - #:use-module (mcron environment) - #:use-module (mcron vixie-time) - #:use-module (srfi srfi-1) - #:use-module (srfi srfi-26) - #:re-export (append-environment-mods)) - + job)) (define* (range start end #:optional (step 1)) "Produces a list of values from START up to (but not including) END. An @@ -49,25 +48,18 @@ optional STEP may be supplied, and (if positive) only every step'th value will go into the list. For example, (range 1 6 2) returns '(1 3 5)." (unfold (cut >= <> end) identity (cute + <> (max step 1)) start)) -;; Internal function (not supposed to be used directly in configuration files; -;; it is exported from the module for the convenience of other parts of the -;; mcron implementation) which takes a value and a list of possible next values -;; (all assumed less than 9999). It returns a pair consisting of the smallest -;; element of the list, and the smallest element larger than the current -;; value. If an example of the latter cannot be found, 9999 will be returned. - -(define (find-best-next current next-list) - (let ((current-best (cons 9999 9999))) - (for-each (lambda (allowed-time) - (if (< allowed-time (car current-best)) - (set-car! current-best allowed-time)) - (if (and (> allowed-time current) - (< allowed-time (cdr current-best))) - (set-cdr! current-best allowed-time))) - next-list) - current-best)) - - +(define (%find-best-next current next-list) + ;; Takes a value and a list of possible next values (all assumed less than + ;; 9999). It returns a pair consisting of the smallest element of the + ;; NEXT-LIST, and the smallest element larger than the CURRENT value. If an + ;; example of the latter cannot be found, 9999 will be returned. + (let loop ((smallest 9999) (closest+ 9999) (lst next-list)) + (match lst + (() (cons smallest closest+)) + ((time . rest) + (loop (min time smallest) + (if (> time current) (min time closest+) closest+) + rest))))) ;; Internal function to return the time corresponding to some near future ;; hour. If hour-list is not supplied, the time returned corresponds to the @@ -89,7 +81,7 @@ go into the list. For example, (range 1 6 2) returns '(1 3 5)." set-component! set-higher-component!) (if (null? value-list) (set-component! time (+ (component time) 1)) - (let ((best-next (find-best-next (component time) (car value-list)))) + (let ((best-next (%find-best-next (component time) (car value-list)))) (if (eqv? 9999 (cdr best-next)) (begin (set-higher-component! time (+ (higher-component time) 1)) -- cgit v1.2.3