Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.compilers > #3120

Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple?

Show all headers | View raw

On Friday, July 15, 2022 at 4:13:42 AM UTC+2, George Neuner wrote:
> In many (actually most) cases, the binary representation of an integer
> can be stored in less space than the text representation.

The output of a command such as (cd /usr/src/linux; grep --only-matching
--recursive "\b[0-9][0-9]*\b") proves the falsity of the above claim.

Binary, fixed-width, representation of integers is statistically more
space-efficient compared to implicit-width textual representation only if the
text representation of the integers includes (for example): a plain 32/64-bit
pointer to the start of the text, a plain 16/32/64-bit relative/absolute
offset to the start of the number in a character array, the [length of the
textual form of the number] in an explicit form.

Binary, fixed-width, representation of integers is more likely to be more
space-efficient than [their textual representation with an implicit length] if
the source of the integers doesn't originate from a human hand typing digits
on a keyboard. For example, when the source of the integers is a
high-precision measurement device, is something with a physical counterpart
(such as: the GPS coordinates of objects spread across Earth's surface), etc.

-atom
[It's still hard to imagine that the size difference would matter in a compiler.
If you're logging a million values a second and saving it to an archive, well,
that's different. -John]

Back to comp.compilers | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? Roger L Costello <costello@mitre.org> - 2022-07-14 10:25 +0000
  Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? gah4 <gah4@u.washington.edu> - 2022-07-14 10:03 -0700
  Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? George Neuner <gneuner2@comcast.net> - 2022-07-14 16:38 -0400
    Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? Spiros Bousbouras <spibou@gmail.com> - 2022-07-15 07:08 +0000
    Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? Jan Ziak <0xe2.0x9a.0x9b@gmail.com> - 2022-07-15 03:02 -0700
      Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? Jan Ziak <0xe2.0x9a.0x9b@gmail.com> - 2022-07-15 10:50 -0700
      Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? George Neuner <gneuner2@comcast.net> - 2022-07-17 16:52 -0400
        Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? Thomas Koenig <tkoenig@netcologne.de> - 2022-07-18 05:44 +0000
      Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? George Neuner <gneuner2@comcast.net> - 2022-07-17 18:01 -0400
  Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? Kaz Kylheku <480-992-1380@kylheku.com> - 2022-07-15 14:41 +0000
  Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? "matt.ti...@gmail.com" <matt.timmermans@gmail.com> - 2022-07-16 05:32 -0700
  Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? Christopher F Clark <christopher.f.clark@compiler-resources.com> - 2022-07-17 13:10 -0400
    Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? gah4 <gah4@u.washington.edu> - 2022-07-17 20:39 -0700
      Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? gah4 <gah4@u.washington.edu> - 2022-07-19 16:39 -0700
        Re: Why does the lexer convert text integer lexemes to binary integers? I thought that lexers should be simple? luser droog <luser.droog@gmail.com> - 2022-07-21 14:16 -0700
      Scannerless parsing was: Why does the lexer convert text integer lexemes ...? "Ev. Drikos" <drikosev@gmail.com> - 2022-07-21 13:41 +0300
        Re: Scannerless parsing was: Why does the lexer convert text integer lexemes ...? "Ev. Drikos" <drikosev@gmail.com> - 2022-07-22 12:29 +0300

csiph-web