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Diffstat (limited to 'doc/api')
-rw-r--r-- | doc/api/utils.texi | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/doc/api/utils.texi b/doc/api/utils.texi index e75dd47..308daee 100644 --- a/doc/api/utils.texi +++ b/doc/api/utils.texi @@ -14,6 +14,27 @@ (use-modules (sly utils repl)) @end example +The Sly REPL is a cooperative REPL server that is integrated into the +game loop. It is the key to live coding games with Sly. To connect +to the REPL server, use the @uref{http://www.nongnu.org/geiser/, +Geiser} extension for GNU Emacs. + +@deffn {Scheme Procedure} start-sly-repl [@var{port}] +Start a cooperative REPL server that listens on the given @code{port}. +By default, this port is 37146. Additionally, a process is scheduled +to poll the REPL server upon every tick of the game loop. +@end deffn + +The Sly REPL detects when the game loop throws an error and enters a +special loop for debugging. When in this state, game state will not +be updated or rendered. When the errors have been fixed, calling the +@code{resume-game-loop} procedure will hand control back to the game +loop. + +@deffn {Scheme Procedure} resume-game-loop +Abort from the error handling loop prompt and resume the game loop. +@end deffn + @node Live Reloading @subsection Live Reloading @@ -21,9 +42,69 @@ (use-modules (sly utils live-reload)) @end example +The live-reload module enables Sly programs to react to changes in the +file system and reload assets automatically, which is useful when +using external programs such as an image editor or map editor. This +makes it easy to see the changes made to game assets quickly. + +@defun live-reload @var{proc} [@var{polling-interval}] +Return a new procedure that re-applies @code{proc} whenever the +associated file is modified. The new procedure returns a signal +(@pxref{Signals}) that contains the return value of @code{proc}. The +first argument to @code{proc} must be a file name string. + +A simple polling method is used to test for updates. Files are polled +every @code{polling-interval} ticks (120 by default). +@end defun + @node Miscellaneous-Utilities @subsection Miscellaneous @example (use-modules (sly utils)) @end example + +Miscellaneous helpful procedures. + +@deffn {Scheme Syntax} define-guardian @var{name} @var{reaper} +Define a new guardian called @code{name} and call @code{reaper} when +an object within the guardian is GC'd. Reaping is ensured to happen +from the same thread that is running the game loop. +@end deffn + +@deffn memoize @var{proc} +Return a memoizing version of @code{proc}. +@end deffn + +@deffn {Scheme Syntax} forever @var{body} @dots{} +Evaluate @code{body} in an unbounded loop. Useful in coroutines that +have no end. +@end deffn + +@deffn {Scheme Syntax} trampoline @var{proc-name} +Create a new procedure that applies the procedure bound to +@code{proc-name} with all given arguments. +@end deffn + +@deffn {Scheme Syntax} chain* @var{args} (@var{proc} @dots{}) . @var{rest} +Handy macro for flattening nested procedure calls where the output of +an inner call is the last argument to the outer call. + +@example +(chain* (list '(1 2) '(3 4)) + (map +) + (fold + 0)) ;; => 10 +@end example + +@end deffn + +@deffn {Scheme Syntax} chain @var{arg} (@var{proc} @dots{}) . @var{rest} +Like @code{chain*} but for a single argument. + +@example +(chain '(1 2 3 4) + (map 1+) + (fold + 0)) ;; => 14 +@end example + +@end deffn |