Comments
Wolfgang Corcoran-Mathe
(13 Aug 2020 04:13 UTC)
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Re: Comments
John Cowan
(14 Aug 2020 01:47 UTC)
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Re: Comments
Vladimir Nikishkin
(25 Aug 2020 03:58 UTC)
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Re: Comments
Wolfgang Corcoran-Mathe
(04 Sep 2020 19:36 UTC)
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Re: Comments Wolfgang Corcoran-Mathe (04 Sep 2020 20:10 UTC)
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Re: Comments
Vladimir Nikishkin
(15 Sep 2020 15:31 UTC)
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Re: Comments Wolfgang Corcoran-Mathe 04 Sep 2020 20:10 UTC
On 2020-09-04 15:36 -0400, Wolfgang Corcoran-Mathe wrote: > The sentence "if the canvas does not exist, it > is created" seems a little vague in its current position. Does this apply > to canvas-cleanup, i.e. does it create a canvas to delete? > > I think it's sufficient merely to add a note to rogers about canvas > creation. You've already done this for draw-line and draw-bezier. I realize after re-reading that I interpreted part of the `rogers' spec as a general requirement. Apologies. The rest of the above can be ignored. An additional comment: I'm not exactly sure what this paragraph means: > v-list may be one of the possible implementations of a frame, in the > SICP terminology. However, in order to avoid nudging the potential > users of the library into a particular implementation of frames, we > opted to specify one of the possible underlying data structures > directly. Converting between this representation, as well as any > other representation, should be a relatively simple exercise. From what comes before, I gather that a v-list is a list of three or more length-two numeric lists. Maybe such a simple structure and its operations should just be described at the head of the specification. (Accessors would also be helpful, to eliminate the need for the hand-rolled cadr and caddr in the `rogers' spec.) -- Wolfgang Corcoran-Mathe <xxxxxx@sigwinch.xyz> "It is better to forget time altogether. Time plays no role at the fundamental level of physics." --Carlo Rovelli