diff options
| -rw-r--r-- | doc/api/scripting.texi | 22 | ||||
| -rw-r--r-- | sly/actor.scm | 13 |
2 files changed, 35 insertions, 0 deletions
diff --git a/doc/api/scripting.texi b/doc/api/scripting.texi index ca2cfd4..299cf0f 100644 --- a/doc/api/scripting.texi +++ b/doc/api/scripting.texi @@ -221,6 +221,28 @@ transformed. @end deffn +@deffn {Scheme Procedure} action-effect-lift @var{proc} +Create an action constructor from @var{proc}, a procedure of any +number of arguments, whose first two arguments are the world being +transformed and the game object being acted upon. The actions +returned from this new procedure specify that @var{proc} should be +performed as an effect on the world, and do not change the actor +itself. + +@example +;; Theoretical procedure that spawns a new enemy next to the current +;; enemy actor. +(define (spawn-enemy world enemy type) + (add-enemy world (enemy-position enemy) (make-enemy type)) + +(define spawn-enemy* (action-effect-lift spawn-enemy)) + +;; Create a new action that spawns a goblin. +(spawn-enemy* 'goblin) +@end example + +@end deffn + @deffn {Scheme Procedure} both @var{a} @var{b} Peform action @var{a} immediately followed by action @var{b}. When the action is run, the remainder of both @var{a} and @var{b} are diff --git a/sly/actor.scm b/sly/actor.scm index fd21a64..5b6d7e3 100644 --- a/sly/actor.scm +++ b/sly/actor.scm @@ -37,6 +37,7 @@ call-with-actor action-lift + action-effect-lift idle both then @@ -106,6 +107,18 @@ transformed." effects (apply proc object args))))) +(define (action-effect-lift proc) + "Create an action constructor from PROC, a procedure of any number +of arguments, whose first two arguments are the world being +transformed and the game object being acted upon. The actions +returned from this new procedure specify that PROC should be performed +as an effect on the world, and do not change the actor itself." + (lambda args + (lambda (world effects object) + (values #f + (list (lambda (world) (apply proc world object args))) + object)))) + (define (idle world effects object) "Do nothing. Do not change OBJECT nor add anything to EFFECTS." (values #f effects object)) |