From: "Vítor De Araújo" <vbuaraujo@sapo.pt>
To: Mark Carter <alt.mcarter@gmail.com>, guile-user@gnu.org
Subject: Re: Is this a good use for "compile"
Date: Mon, 19 Feb 2018 21:08:25 -0300 [thread overview]
Message-ID: <5d3802ce-88b8-7b8a-13e5-b1fbd9dfd0c9@sapo.pt> (raw)
In-Reply-To: <d5f145f3-ce31-71e4-d256-229ec21d2668@gmail.com>
On 18/02/2018 18:56, Mark Carter wrote:
> New scheme user here.
>
> Suppose I'm writing a spreadsheet. The user inputs a formula for a cell.
>
> The plan is to use guile's peg parser to convert the formula into a
> lambda expression, which I then compile in order to speed-up subsequent
> processing.
>
> So, suppose I convert the user's formula to a list, which turns out to
> be, for example: '(lambda (x) (+ x 13)) and compile it and save it in a
> formula table:
>
> (hash-set! my-cell-formulae some-cell-ref (compile '(lambda (x) (+ x 13))))
>
> So I can I expect a speed-up by having done the compile, as opposed to
> an eval?
>
> I assume the answer is "yes", but I wanted to check.
We can try this out:
scheme@(guile-user)> (use-modules (system base compile))
scheme@(guile-user)> (define exp '(lambda (n)
(let loop ([i n] [total 0])
(if (= i 0)
total
(loop (1- i) (+ i total))))))
scheme@(guile-user)> (define f1 (eval exp (interaction-environment)))
scheme@(guile-user)> (define f2 (compile exp #:env
(interaction-environment)))
scheme@(guile-user)> ,time (f1 1000000)
$2 = 500000500000
;; 0.845240s real time, 0.895351s run time. 0.071494s spent in GC.
scheme@(guile-user)> ,time (f2 1000000)
$3 = 500000500000
;; 0.067317s real time, 0.067278s run time. 0.000000s spent in GC.
So the answer does seem to be "yes": the compiled procedure is much faster.
--
Vítor De Araújo
https://elmord.org/
next prev parent reply other threads:[~2018-02-20 0:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-18 21:56 Is this a good use for "compile" Mark Carter
2018-02-19 17:30 ` Matt Wette
2018-02-20 0:08 ` Vítor De Araújo [this message]
2018-02-20 9:28 ` Mark Carter
-- strict thread matches above, loose matches on Subject: below --
2018-02-20 11:03 Mark Carter
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