diff options
| -rw-r--r-- | 2d/signals.scm | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/2d/signals.scm b/2d/signals.scm index 04de9c0..85cc5af 100644 --- a/2d/signals.scm +++ b/2d/signals.scm @@ -51,7 +51,8 @@ signal-and signal-or signal-when - signal-unless)) + signal-unless + signal-do)) ;;; ;;; Signals @@ -281,3 +282,14 @@ is never true." #:transformer (lambda (value prev from) (signal-ref consequent)) #:connectors (list predicate consequent))) + +(define (signal-do proc signal) + "Create a new signal that applies PROC with incoming values from +SIGNAL. The value of the new signal will always be the value of +SIGNAL. This signal is a convenient way to apply a side-effect to a +signal value." + (make-signal + #:transformer (lambda (value prev from) + (proc value) + value) + #:connectors (list signal))) |