cheap diazepam cheap xenical nokia ringtones qwest ringtones zanaflex online diazepam online verizon ringtones free motorola ringtones order lortab prozac online ericsson ringtones but ortho cheap cyclobenzaprine cheap celexa free ringtones phentermine free cool ringtones cheap prozac free qwest ringtones cialis online sprint ringtones nexium online real ringtones sagem ringtones tracfone ringtones free nokia ringtones free punk ringtones mp3 ringtones sony ringtones ativan online but hgh free midi ringtones alltel ringtones cheap flexeril sony ericsson ringtones motorola ringtones vicodin online free tracfone ringtones buy soma levitra online free motorola ringtones cheap didrex cheap sildenafil pharmacy online online zoloft online hydrocodone online free sony ringtones cingular ringtones viagra buy paxil ambien online buy lortab order hydrocodone vigrx online cheap ativan hgh online sildenafil online buy viagra ortho online nextel ringtones lisinopril free funny ringtones free sony ericsson ringtones buy vicodin hydrocodone order ativan mono ringtones clonazepam levitra free sprint ringtones cialis online sony ringtones cheap levitra zanaflex online phentermine celexa online ultracet online wwe ringtones free sharp ringtones buy norco soma online cheap ultracet free cingular ringtones cheap adipex cheap xenical cheap albuterol cheap tenuate cheap ortho free music ringtones sagem ringtones cheap lisinopril meridia online cheap propecia cheap vigrx cheap diethylpropion cheap albuterol mp3 ringtones meridia online free ringtones cheap ultram soma online cheap lortab cheap sildenafil free nextel ringtones cheap lorazepam free funny ringtones diethylpropion online free ringtones funny ringtones cingular ringtones cheap soma nokia ringtones clonazepam online zyban online clomid online buy prozac online valium order lisinopril meridia online buy tramadol sharp ringtones free midi ringtones flexeril online real ringtones celexa online zoloft online free nextel ringtones ericsson ringtones free music ringtones mtv ringtones order ultram buy valium viagra online lorazepam online cheap cialis cheap phentermine buy nexium samsung ringtones cheap norco meridia online sprint ringtones buy rivotril order carisoprodol carisoprodol online cyclobenzaprine online free qwest ringtones free qwest ringtones cheap fioricet verizon ringtones punk ringtones cheap hoodia pharmacy online online tracfone ringtones tramadol cheap rivotril tramadol online didrex online cheap fioricet music ringtones cheap albuterol free nokia ringtones buy viagra buy alprazolam buy xenical pharmacy online online free funny ringtones order zanaflex free ericsson ringtones cyclobenzaprine online adipex online cheap xanax free alltel ringtones free qwest ringtones ultram online sonyericsson ringtones free samsung ringtones cheap lortab free mono ringtones free samsung ringtones zyban online cheap celexa free funny ringtones wwe ringtones cheap rivotril but clomid buy fioricet buy hgh cheap lipitor cheap hoodia clonazepam online cool ringtones tenuate online cheap vicodin real ringtones free sonyericsson ringtones buy hoodia buy tramadol nextel ringtones cheap alprazolam ambien online 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!"