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| author | David Thompson <dthompson2@worcester.edu> | 2016-02-10 21:59:10 -0500 |
|---|---|---|
| committer | David Thompson <dthompson2@worcester.edu> | 2016-02-10 22:01:38 -0500 |
| commit | 5571463e79247d6cb338a015e5bbf94d4bafde44 (patch) | |
| tree | 98cc33f34a40edb4fe76730f2796f54542192af3 | |
| parent | f36ee4549eca5a6754289befdda9bf9cc93a0ee9 (diff) | |
signal: Add signal-map-maybe.
* sly/signal.scm (signal-map-maybe): New procedure.
| -rw-r--r-- | sly/signal.scm | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/sly/signal.scm b/sly/signal.scm index 42cce40..41365a9 100644 --- a/sly/signal.scm +++ b/sly/signal.scm @@ -41,7 +41,9 @@ signal-set! signal-merge signal-zip - signal-map signal-sample-on + signal-map + signal-map-maybe + signal-sample-on signal-negate signal-fold signal-filter @@ -273,6 +275,15 @@ or more SIGNALs." (%signal-set! self (current-value))) inputs))) +(define (signal-map-maybe proc signal . rest) + "Create a new signal that applies PROC to the values stored in +SIGNAL ... if all of them are not #f." + (apply signal-map + (lambda args + (and (every identity args) + (apply proc args))) + signal rest)) + (define (signal-sample-on value-signal sample-signal) "Create a new signal that takes on the value of VALUE-SIGNAL whenever SAMPLE-SIGNAL receives a new value." |