MIT Scheme primitives in DrScheme

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Chris Conley

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Feb 6, 2009, 11:04:34 AM2/6/09
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Is anyone else using DrScheme and having any luck with the exercises
at the end of Section 1.2? It seems that DrScheme doesn't have the
(runtime) primitive.

Is there a library out there or something? Or is everybody just using
MIT Scheme?

Thanks!
Chris
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Chris Conley

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Feb 6, 2009, 11:25:38 AM2/6/09
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I'm using R5RS, and have tried a few others with no luck.

On Fri, Feb 6, 2009 at 11:16 AM, Nadim Ratani <nra...@gmail.com> wrote:
Are you using the right mode in Dr. Scheme? I'm not that far yet, but you can choose the subset of scheme that you want.

Nadim
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Bill Mill

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Feb 6, 2009, 11:31:26 AM2/6/09
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Chris Conley

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Feb 6, 2009, 11:36:52 AM2/6/09
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Thanks Bill. Yeah I found that too, but R5RS doesn't respond to any of those procedures either. I'll double check later on today though.

Chris Conley

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Feb 6, 2009, 11:45:03 AM2/6/09
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It looks like "Pretty Big" responds to (current-gc-milliseconds), but I haven't had time to make sure that's what we want. I'll try to dive into later today.

Nicolás Canevali

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Feb 6, 2009, 2:15:04 PM2/6/09
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I've had trouble with those exercises as well. You can use FreeTime, I think it's called, but that one doesn't have the printing procedures. At last, I had to use the command line utility mzscheme, and it worked fine, even though it's much less pleasant to code in than DrScheme. But it's only for this section, there won't be any more time-related exercises in the next chapters.

Mario Romero Zavala

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Feb 6, 2009, 8:32:42 PM2/6/09
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FWIW I'm using current-milliseconds in place of the non existant runtime.

here's some relevant docs:
http://download.plt-scheme.org/doc/103p1/html/mzscheme/node134.htm

James Coglan

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Feb 8, 2009, 12:02:51 PM2/8/09
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> FWIW I'm using current-milliseconds in place of the non existant runtime.

Also FWIW: I'm rolling my own Scheme in Ruby to play along with SICP.
I seem to remember getting all zeros on benchmarking in PLT because it
was too fast; fortunately mine's slow enough to give you decent
numbers! It has (runtime) which returns microseconds, and enough code
to do chapter 1 of SICP. I'm working on macros and continuations, any
Ruby hackers feel like playing with it can get it on github:

http://github.com/jcoglan/heist
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