There are two conveniences that will be useful on writers:
methods using a DefaultFrame (depends on #148) instead of requiring the user to pass a Frame
methods that return just the output type and discard the A value in the Picture (A is almost always Unit; discarding it is what draw does.)
These can both be implemented as syntax. (It's good to not have redundant methods on the type classes / algebras, though this is not consistently followed.)
(What's below is more speculative.)
There are a number of writers that don't require any input beyond the Picture and Frame (e.g. writing to an value, like Base64 or a BufferedImage). To ensure consistency for these kinds of writers we can define a subtype of Writer, let's say ValueWriter:
There are two conveniences that will be useful on writers:
DefaultFrame(depends on #148) instead of requiring the user to pass aFrameAvalue in thePicture(Ais almost alwaysUnit; discarding it is whatdrawdoes.)These can both be implemented as syntax. (It's good to not have redundant methods on the type classes / algebras, though this is not consistently followed.)
(What's below is more speculative.)
There are a number of writers that don't require any input beyond the
PictureandFrame(e.g. writing to an value, likeBase64or aBufferedImage). To ensure consistency for these kinds of writers we can define a subtype ofWriter, let's sayValueWriter:Then we can define syntax on
ValueWriterthat all implementations will automatically have. Probably something likewhere the type variable
Outis used to select theValueWriterinstance.