RE Module Performance

Jeremy Sanders jeremy at jeremysanders.net
Thu Jul 25 09:36:25 EDT 2013


wxjmfauth at gmail.com wrote:

> Short example. Writing an editor with something like the
> FSR is simply impossible (properly).

http://www.gnu.org/software/emacs/manual/html_node/elisp/Text-Representations.html#Text-Representations

"To conserve memory, Emacs does not hold fixed-length 22-bit numbers that are 
codepoints of text characters within buffers and strings. Rather, Emacs uses a 
variable-length internal representation of characters, that stores each 
character as a sequence of 1 to 5 8-bit bytes, depending on the magnitude of 
its codepoint[1]. For example, any ASCII character takes up only 1 byte, a 
Latin-1 character takes up 2 bytes, etc. We call this representation of text 
multibyte.

...

[1] This internal representation is based on one of the encodings defined by 
the Unicode Standard, called UTF-8, for representing any Unicode codepoint, but 
Emacs extends UTF-8 to represent the additional codepoints it uses for raw 8-
bit bytes and characters not unified with Unicode.

"

Jeremy





More information about the Python-list mailing list