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Re: trimming a string

• To: mathgroup at smc.vnet.net
• Subject: [mg50868] Re: [mg50861] trimming a string
• From: "Wolf, Hartmut" <Hartmut.Wolf at t-systems.com>
• Date: Sat, 25 Sep 2004 01:55:06 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

>-----Original Message-----
>From: Akos Beleznay [mailto:abeleznay at equitas-capital.com]
To: mathgroup at smc.vnet.net
>Sent: Friday, September 24, 2004 10:42 AM
>To: mathgroup at smc.vnet.net
>Subject: [mg50868] [mg50861] trimming a string
>
>
>I would appreciate if somebody could show me a simple way of trimming a
>string. (I did it a hard way, but suspect an elegant solution.)
>
>Trim(a_string): returns a copy of a string without leading and trailing
>spaces.
>
[...]
>
>Akos Beleznay
[...]


Aknos,

I don't your solution, but here is another one, striktly unelegant:

 
In[80]:=
trimString[str_] := 
  Module[{s, t, u}, t = Transpose[StringPosition[str, " "]][[1]];
    s = t - Join[{0}, Drop[t, -1] + 1];
    u = #[[{1, -1}, 2]] & /@ Split[Transpose[{s, t}], First[#2] == 0 &];
    Fold[StringDrop, str, Reverse@Cases[u, {1, _} | {_, StringLength[str]}]]]

In[81]:= ss = "In the beginning there was no earth or sky";

In[82]:= ss === trimString[ss]
Out[82]= True
In[83]:= ss === trimString[StringJoin["  ", ss]]
Out[83]= True
In[84]:= ss === trimString[StringJoin[ss, " "]]
Out[84]= True

(But possibly, for string manipulation, you might like to search for a different tool, Perl perhaps)

---
Hartmut