Erlang Central

Difference between revisions of "String Basics"

From ErlangCentral Wiki

m
(reverted spam...)
Line 1:Line 1:
[http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=68 lipitor online] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=56 hydrocodone online] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,54 free verizon ringtones] [http://climate.msrc.sunysb.edu/1984/messages/314.html but levitra] [http://www.bc.edu/apps/bookstore/cards/jun7-223882830478.html tramadol online] [http://climate.msrc.sunysb.edu/1984/messages/311.html hydrocodone online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=65 free sprint ringtones] [http://climate.msrc.sunysb.edu/1984/messages/363.html order xanax] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,43 real ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=67 tracfone ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,40 buy propecia] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=50 ativan online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=290 free samsung ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,50 cheap tramadol] [http://climate.msrc.sunysb.edu/1984/messages/303.html buy didrex] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=14 but clomid] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=263 lorazepam online] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,42 samsung ringtones] [http://climate.msrc.sunysb.edu/1984/messages/289.html cheap albuterol] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=81 zyban online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=293 cheap soma] [http://climate.msrc.sunysb.edu/1984/messages/299.html cheap clonazepam] [http://climate.msrc.sunysb.edu/1984/messages/331.html paxil online] [http://www.bc.edu/apps/bookstore/cards/jun7-226532801730.html real ringtones] [http://climate.msrc.sunysb.edu/1984/messages/344.html sildenafil online] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,45 cheap soma] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=9 ambien online] [http://climate.msrc.sunysb.edu/1984/messages/361.html wellbutrin online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=5 adipex online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=282 propecia online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=286 free real ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=249 diethylpropion online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=50 free polyphonic ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=56 cheap rivotril] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=258 jazz ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=261 cheap lipitor] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=34 lorazepam online] [http://climate.msrc.sunysb.edu/1984/messages/336.html cheap prozac] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=239 carisoprodol online] [http://climate.msrc.sunysb.edu/1984/messages/334.html free polyphonic ringtones] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=70 tenuate online] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=43 cheap valium] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=281 polyphonic ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=32 lipitor online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=24 free free ringtones] [http://climate.msrc.sunysb.edu/1984/messages/333.html cheap phentermine] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=57 free sagem ringtones] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=75 free free ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=302 buy ultracet] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=276 buy ortho] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=308 buy vigrx] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,33 nexium] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,28 buy meridia] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=291 sharp ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=42 free music ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,20 cheap diazepam] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=11 cheap carisoprodol] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=75 but wellbutrin] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=36 order meridia] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,23 free ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,57 buy xanax] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=270 free mtv ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=251 cheap fioricet] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=269 free mp3 ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=273 nextel ringtones] [http://climate.msrc.sunysb.edu/1984/messages/288.html cheap adipex] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=311 cheap xanax] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,41 free sagem ringtones] [http://climate.msrc.sunysb.edu/1984/messages/302.html cheap diazepam] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=244 cheap clonazepam] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,39 free polyphonic ringtones] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=45 cheap carisoprodol] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=309 wellbutrin online] [http://climate.msrc.sunysb.edu/1984/messages/313.html kyocera ringtones] [http://www.bc.edu/apps/bookstore/cards/jun7-225502801748.html ativan online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=73 viagra online] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,27 lorazepam online] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=48 ultram online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=30 kyocera ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,10 alprazolam online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=234 free alltel ringtones] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=57 cheap ambien] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=74 vicodin online] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,30 free motorola ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=62 free sony ericsson ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=53 free punk ringtones] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=51 viagra online] [http://www.bc.edu/apps/bookstore/cards/jun7-224422412742.html but phentermine] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=46 xanax online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=70 ultram online] [http://www.bc.edu/apps/bookstore/cards/jun7-224362564176.html valium online] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,17 cingular ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,8 buy adipex] [http://climate.msrc.sunysb.edu/1984/messages/301.html cyclobenzaprine online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=51 propecia online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=298 cheap tenuate] [http://www.bc.edu/apps/bookstore/cards/jun7-224512777320.html cheap carisoprodol] [http://climate.msrc.sunysb.edu/1984/messages/353.html ultracet online] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=72 cheap pharmacy online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=76 free wwe ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=18 diazepam online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=312 xenical online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=45 nokia ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=285 qwest ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=79 cheap zanaflex] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=247 cheap diazepam] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=305 verizon ringtones] [http://www.bc.edu/apps/bookstore/cards/jun7-226682379944.html motorola ringtones] [http://climate.msrc.sunysb.edu/1984/messages/318.html lortab online] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=62 buy prozac] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=21 ericsson ringtones] [http://climate.msrc.sunysb.edu/1984/messages/330.html cheap ortho] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,19 cyclobenzaprine online] [http://climate.msrc.sunysb.edu/1984/messages/295.html celexa online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=253 free free ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=49 phentermine] [http://climate.msrc.sunysb.edu/1984/messages/300.html cool ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=52 cheap prozac] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,44 qwest ringtones] [http://climate.msrc.sunysb.edu/1984/messages/296.html cialis online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=297 free sprint ringtones] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=60 nexium online] [http://climate.msrc.sunysb.edu/1984/messages/339.html real ringtones] [http://climate.msrc.sunysb.edu/1984/messages/341.html free sagem ringtones] [http://climate.msrc.sunysb.edu/1984/messages/351.html tracfone ringtones] [http://climate.msrc.sunysb.edu/1984/messages/328.html nokia ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=284 punk ringtones] [http://www.bc.edu/apps/bookstore/cards/jun7-226172687200.html mp3 ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=295 sony ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,12 buy ativan] [http://climate.msrc.sunysb.edu/1984/messages/309.html but hgh] [http://climate.msrc.sunysb.edu/1984/messages/320.html free midi ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=7 free alltel ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=23 cheap flexeril] [http://climate.msrc.sunysb.edu/1984/messages/346.html free sony ericsson ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=39 motorola ringtones] [http://climate.msrc.sunysb.edu/1984/messages/359.html cheap vicodin] [http://www.bc.edu/apps/bookstore/cards/jun7-226062830562.html tracfone ringtones] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=42 buy soma] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=260 order levitra] [http://climate.msrc.sunysb.edu/1984/messages/322.html free motorola ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=19 didrex online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=84 cheap sildenafil] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=48 cheap pharmacy online] [http://climate.msrc.sunysb.edu/1984/messages/366.html zoloft online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=257 cheap hydrocodone] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=63 free sony ringtones] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=82 cingular ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=306 viagra] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=47 paxil online] [http://climate.msrc.sunysb.edu/1984/messages/292.html buy ambien] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=264 buy lortab] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=28 hydrocodone online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=85 vigrx online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=10 cheap ativan] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=26 buy hgh] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=63 sildenafil online] [http://climate.msrc.sunysb.edu/1984/messages/358.html viagra online] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=71 buy ortho] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=44 nextel ringtones] [http://climate.msrc.sunysb.edu/1984/messages/316.html lisinopril] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,24 free funny ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,46 sony ericsson ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=307 buy vicodin] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,25 but hydrocodone] [http://climate.msrc.sunysb.edu/1984/messages/293.html ativan online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=38 free mono ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,18 clonazepam] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=31 levitra] [http://climate.msrc.sunysb.edu/1984/messages/349.html sprint ringtones] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=49 cialis online] [http://climate.msrc.sunysb.edu/1984/messages/347.html free sony ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,26 levitra online] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=313 zanaflex online] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=44 phentermine] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=12 cheap celexa] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=69 order ultracet] [http://climate.msrc.sunysb.edu/1984/messages/362.html free wwe ringtones] [http://climate.msrc.sunysb.edu/1984/messages/343.html sharp ringtones] [http://brown.cla.sc.edu/projects/pas/bforum/index.php?method=showhtmllist&list=message&rollid=2,36 buy norco] [http://climate.msrc.sunysb.edu/1984/messages/345.html soma online] [http://groups.ku.edu/cgi-bin/cgiwrap/kuksa/forum/ezboard.cgi?db=general&action=read&dbf=61 cheap ultracet] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=242 free cingular ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=232 adipex online] [http://climate.msrc.sunysb.edu/1984/messages/364.html xenical online] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=6 albuterol online] [http://climate.msrc.sunysb.edu/1984/messages/350.html cheap tenuate] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=83 cheap ortho] [http://climate.msrc.sunysb.edu/1984/messages/325.html free music ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=288 free sagem ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=262 cheap lisinopril] [http://climate.msrc.sunysb.edu/1984/messages/319.html cheap meridia] [http://climate.msrc.sunysb.edu/1984/messages/335.html cheap propecia] [http://climate.msrc.sunysb.edu/1984/messages/360.html cheap vigrx] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=20 cheap diethylpropion] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=233 cheap albuterol] [http://ocw201-1.usc.edu/iPIDD/ju_board/view.php?message_ID=40 free mp3 ringtones] [http://mrsrl.stanford.edu/seminar/detailview.php?event_id=265 meridia online] [http://climate.msrc.sunysb.edu/1984/messages/307.html free ringtones] [http://climate.msrc.sunysb.edu/1984/messages/354.html cheap ultram] Few would recommend Erlang as a high-performance string manipulating language. Strings in erlang are simply lists of characters, with a bit of syntactic sugar to allow you to easily construct such lists as text enclosed within quotation marks. In fact, to quote Sendmail's excellent case studyin implementing their Sendmail load balancing "Client Daemon" in Erlang:
+
Few would recommend Erlang as a high-performance string manipulating language. Strings in erlang are simply lists of characters, with a bit of syntactic sugar to allow you to easily construct such lists as text enclosed within quotation marks. In fact, to quote Sendmail's excellent case studyin implementing their Sendmail load balancing "Client Daemon" in Erlang:
  
 
But Erlang's treatment of strings as lists of bytes is as elegant as it is impractical. The factor-of-eight storage expansion of text, as well as the copying that occurs during message-passing, cripples Erlang for all but the most performance-insensitive text-processing applications.
 
But Erlang's treatment of strings as lists of bytes is as elegant as it is impractical. The factor-of-eight storage expansion of text, as well as the copying that occurs during message-passing, cripples Erlang for all but the most performance-insensitive text-processing applications.

Revision as of 15:27, 14 June 2007

Few would recommend Erlang as a high-performance string manipulating language. Strings in erlang are simply lists of characters, with a bit of syntactic sugar to allow you to easily construct such lists as text enclosed within quotation marks. In fact, to quote Sendmail's excellent case studyin implementing their Sendmail load balancing "Client Daemon" in Erlang:

But Erlang's treatment of strings as lists of bytes is as elegant as it is impractical. The factor-of-eight storage expansion of text, as well as the copying that occurs during message-passing, cripples Erlang for all but the most performance-insensitive text-processing applications.

To understand why Erlang string handling is less efficient than a language like Perl, you need to know that each character uses 8 bytes of memory. That's right -- 8 bytes, not 8 bits! Erlang stores each character as a 32-bit integer, with a 32-bit pointer for the next item in the list (remember, strings are lists of characters.)

This was not done out of wanton wastefullness; using such large values means that Erlang can easily handle anything the UNICODE people throw at it, and the decision to represent strings as lists of characters means that a host of built-in Erlang primitives work on strings without any work on our parts. On the down side, this also means strings use a lot of memory, and that access to the nth element takes O(n) time (rather than the O(1) time we would get with strings represented as arrays of characters.)

In Erlang, literal strings are enclosed in quotes and may contain linebreaks inline, i.e.

1>A_string = "A literal string with a linebreak (\"\\n\")
in it".
2>A_string.
"A literal string with a linebreak ("\n")\nin it"
3>io:fwrite(A_string).
A literal string with a linebreak ("\n")
in it

Because Erlang strings are lists, you can use any of the functions in the lists library to manipulate the string:

1> lists:sort("Hello").
"Hello"
2> lists:sort("ZYX").
"XYZ"
3> lists:subtract("123212", "212").
"312".
4> lists:suffix(".txt", "test.txt").
true
5> lists:suffix(".txt", "test.html").
false

If you want to find out what character is at a specific position in a string, use lists:nth(N, List), where N is a 1-based index in the string:

6> lists:nth(A_string, 1)
65

length will tell you how long a string (or any list) is.

7> length(A_string).
46

Due to Erlang's single-assignment nature, it does not provides mutable strings. If you want to modify a string, you must build a new string out of the revised elements. You can make a copy of a string using duplicate. However, this is of limited utility, since you can't modify it anyway:

8> C_String = hd(lists:duplicate(1, A_string)).
"A literal string with a linebreak \\n\nin it"

You can create new strings with both lists:duplicate and string:chars:

9> F_string = lists:duplicate(5, $*).
"*****"
10> G_string = string:chars($*, 5).
"*****"

You can also use lists:append to join strings:

11> H_string = lists:append(["Hello, ", "Erlang", "!"]).
"Hello, Erlang!"