[plt-scheme] typed scheme type checking takes very long

From: Sam Tobin-Hochstadt (samth at ccs.neu.edu)
Date: Tue Feb 23 16:00:31 EST 2010

On Tue, Feb 23, 2010 at 3:24 PM, keydana at gmx.de <keydana at gmx.de> wrote:
> Hi all,
> I am wondering if I'm doing something wrong using typed scheme - it takes about 20 seconds on my machine (Mac Book Pro with 2,4 Ghz Intel Core 2 Duo and 4 GB) to typecheck about 130 lines of code, consisting mainly of data definitions and functions (that is, after enhancing the memory to 256 MB "on demand")...
> Is this normal, and if so, what could I do? Further enhance the memory (where can I do this?). Or might there be a problem in the code (I can send it)?

Unfortunately, Typed Scheme is not really fast right now.  The next
result should be somewhat faster, but not fast enough.  I hope to make
it faster in the future.

You can increase the memory from the Language preference panel.

You can also compile files with the 'mzc' command-line program, which
will both run faster and save the results of compilation and

> And an additional question (just for curiosity, for now) - when a typed scheme application goes "productive", would the type checking be disabled (for performance reasons, with no-check), so it would be mainly a help to the programmer during development?
> (BTW although I'm at the beginning only, I already start to find it really helpful, and the error messages are informative, too :-) )

No, because all of the typechecking happens at compile time, so there
is no runtime performance cost.

Thanks for using Typed Scheme.
sam th
samth at ccs.neu.edu

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