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| author | Hugo Hörnquist <hugo@hornquist.se> | 2019-10-05 23:58:03 +0200 |
|---|---|---|
| committer | Hugo Hörnquist <hugo@hornquist.se> | 2019-10-05 23:58:03 +0200 |
| commit | 68dfd8bb5abcc449500614c46566ffa4a83177a4 (patch) | |
| tree | e1259834ad04db9fe2db7fec526cf4fd52b26990 | |
| parent | Fix day-stream, and in effect terminal output. (diff) | |
| download | calp-68dfd8bb5abcc449500614c46566ffa4a83177a4.tar.gz calp-68dfd8bb5abcc449500614c46566ffa4a83177a4.tar.xz | |
Documentation of stream behavior.
| -rw-r--r-- | module/srfi/srfi-41/util.scm | 14 | ||||
| -rw-r--r-- | module/vcomponent/group.scm | 5 |
2 files changed, 16 insertions, 3 deletions
diff --git a/module/srfi/srfi-41/util.scm b/module/srfi/srfi-41/util.scm index 050e1d2e..be363146 100644 --- a/module/srfi/srfi-41/util.scm +++ b/module/srfi/srfi-41/util.scm @@ -24,11 +24,19 @@ (define-public (stream-insert < item s) (interleave-streams < (list (stream item) s))) -(define-public (filter-sorted-stream proc stream) +;; Requires that stream is a total order in regards to what we filter +;; on. From there it knows that once it has found the first element +;; that satisfies our predicate all remaining elements satisfying pred +;; will be in direct succession. +(define-public (filter-sorted-stream pred stream) (stream-take-while - proc (stream-drop-while - (negate proc) stream))) + pred (stream-drop-while + (negate pred) stream))) + +;; Simmilar to the regular @code{filter-sorted-stream}, but once an +;; element satisfies @code{keep-remaning?} then the remaining tail +;; of the stream is all assumed to be good. (define-public (filter-sorted-stream* pred? keep-remaining? stream) (cond [(stream-null? stream) stream-null] [(keep-remaining? (stream-car stream)) stream] diff --git a/module/vcomponent/group.scm b/module/vcomponent/group.scm index 7733d981..46160a3a 100644 --- a/module/vcomponent/group.scm +++ b/module/vcomponent/group.scm @@ -20,6 +20,11 @@ (let ((head (stream-take-while (ein? day) stream)) (tail + ;; This is a filter, instead of a stream-span together with head, + ;; since events can span multiple days. + ;; This starts with taking everything which end after the beginning + ;; of tommorow, and finishes with the rest when it finds the first + ;; object which begins tomorow (after midnight, exclusize). (filter-sorted-stream* (lambda (e) (time<? tomorow (attr e 'DTEND))) (lambda (e) (time<=? tomorow (attr e 'DTSTART))) |