[REBOL] Speed and Memory Management in REBOL Re:(2)
From: jelinem1:nationwide at: 6-Sep-2000 9:40
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I always thought it was more "efficient" to read in and write a block of
data at a time (or the whole file) as opposed to a line of some arbitrary
length. I guess it depends on the OS treatment of buffering data from the
device when reading in line-by-line.
IMO If you are worried about memory efficiency, program in C. Interpreted
languages are inefficient by design, however much I prefer them (esp
REBOL).
[bo--rebol--com] on 09/05/2000 05:37:39 PM
From: [bo--rebol--com] on 09/05/2000 05:37 PM
Please respond to [list--rebol--com]
To: [list--rebol--com]
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Subject: [REBOL] Speed and Memory Management in REBOL Re:
princepawn,
Attached you will find an example that should allow CSV conversion of a
file of any length.
Shocked and honored that simple old %convert-csv.r is one of the most
popular scripts!
Have fun!
-Bo
On 5-Sep-2000/12:52:36-7:00, [princepawn--lycos--com] wrote:
>I was glancing at one of the most popular scripts at the REBOL archive and
developed some questions:
>1- Is it possible to incrementally write to a file in REBOL?
>2- Is it possible to append to a file in REBOL
>3- This script seems in-efficient and memory wasteful: it reads and entire
file into a temporary array and then converts the array. In Perl, I could
do each conversion as I read in each line and write each line out after
each conversion.
>REBOL [
> Title: "Comma-Seperated-Values to REBOL converter"
> Date: 16-Jun-1999
> Author: "Bohdan Lechnowsky"
> Email: [bo--rebol--com]
> File: %convert-csv.r
> Purpose: <lb>
> Convert CSV files to REBOL blocks
> <rb>
> Category: [file util db text 2]
>]
>
>csv: read/lines to-file ask "Filename to convert from CSV: "
>
>block: make block! 100
>
>headings: parse/all first csv ","
>
>foreach line next csv [append block parse/all line ","]
>
>save to-file ask "Filename to save to: " head insert/only block headings
>
>Get your FREE Email and Voicemail at Lycos Communications at
>http://comm.lycos.com
>
--
Bohdan "Bo" Lechnowsky
REBOL Adventure Guide
REBOL Technologies 707-467-8000 (http://www.rebol.com)
Download the REBOL Messaging Language
The Official Source for REBOL Books (http://www.REBOLpress.com)
(See attached file: new-csv.r)
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