| From: Thomas Lord <[email protected]>
| Date: Sat, 19 Sep 2009 15:49:47 -0700
|
| On Sat, 2009-09-19 at 01:24 -0400, John Cowan wrote:
| [....]
| > 2) Algorithms where you want to modify strings in the middle are rare,
|
| Claims like this always make the hairs on the back of my
| neck stand up. There are two problems with them.
| First, there isn't a really good empirical way to establish
| such claims. Second, rarity per se, is not the most
| important consideration.
|
| Surely if we scan the source for PLT or various Scheme
| compilers, SLIB, and similar systems we'll find that
| string mutation is less common than immutable uses of
| strings. Well, I haven't actually *checked* but I wouldn't
| be surprised. Still, that tells us little about what
| code there is that we can't see and won't here about and it
| tells us even less about what kinds of code people will
| want to write in 3 years.
Below are the occurences of string-set! in SLIB. One frequent pattern
of use is to make a string using MAKE-STRING; then fill it with
STRING-SET!. Accumulating characters with STRING-APPEND is a bad
idea; it turns a O(N) process into O(N^2). So I guess lists-of-chars
and LIST->STRING would be the alternative to MAKE-STRING with
STRING-SET!.
-=-=-=-=-
array.scm:375: ((if (string? store) string-set! vector-set!)
To implement uniform character arrays.
byte.scm:89: (string-set! new idx (integer->char (byte-ref bts idx))))))
Byte-vectors implemented from strings.
chap.scm
CHAP:NEXT-STRING increments (in the lexicographic order) a copy of a
given string.
format.scm:725: (string-set! format:fn-str format:fn-len c)
format.scm:728: (string-set! format:en-str format:en-len c)
format.scm:769: (string-set! format:en-str format:en-len c)
format.scm:779: (string-set! format:fn-str i
format.scm:785: (string-set! format:fn-str i #\0))))
format.scm:794: (string-set! format:fn-str (- i n) (string-ref
format:fn-str i))))
format.scm:805: (string-set! format:fn-str 0 #\1)
format.scm:810: (string-set! format:fn-str i (integer->char
format.scm:837: (string-set! format:fn-str format:fn-len #\0)
format.scm:1631: (string-set! cap-str i (char-downcase c))
format.scm:1634: (string-set! cap-str i (char-upcase c)))))))))
One use is capitalizing a copy of a string. The other occurences are
harder to figure.
genwrite.scm:261: (string-set! result k (string-ref str j))
Fills in the result of a call to MAKE-STRING.
getparam.scm:109: (string-set! str i #\-))))))
Converting space to "-" in copy of a string.
http-cgi.scm:
HTTP:READ-QUERY-STRING and CGI:READ-QUERY-STRING fill strings returned
by MAKE-STRING.
lineio.scm:60: (string-set! str i char)))))
READ-LINE! fills an argument string with characters read from a port.
matfile.scm:129: (string-set! namstr idx (read-char port)))
MATFILE:READ-MATRIX reads characters into a string returned by MAKE-STRING.
printf.scm:
SPRINTF stores output into string passed as argument.
sc2.scm:
SUBSTRING-MOVE-LEFT!, SUBSTRING-MOVE-RIGHT!, and SUBSTRING-FILL!
sc4opt.scm:35: (string-set! s i obj)))
STRING-FILL!
scanf.scm:105: (string-set! str i
(read-input-char))))))))
scanf.scm:225: (string-set! str i (read-input-char)))))
Filling string made by MAKE-STRING.
strcase.scm:
STRING-UPCASE!, STRING-DOWNCASE!, and STRING-CAPITALIZE!
strport.scm:39: (string-set! buf i c)
CALL-WITH-OUTPUT-STRING fills string created by MAKE-STRING or
extended with STRING-APPEND.
transact.scm:116: (string-set! str idx (read-char iport))
transact.scm:121: (string-set! name idx (read-char iport))
WORD-LOCK:CERTIFICATE fills result of MAKE-STRING with characters read
from a port.
xml-parse.scm:263: (string-set! buffer i c)
xml-parse.scm:313: (string-set! buffer i c)
xml-parse.scm:331: (string-set! buffer i c)
xml-parse.scm:349: (else (string-set! buffer idx chr))))))
Seems to be filling result of MAKE-STRING with read characters.
yasyn.scm:27: (cons string-ref string-set!))
Not a clue.
_______________________________________________
r6rs-discuss mailing list
[email protected]
http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
