Working with Strings

*To*: mathgroup at smc.vnet.net*Subject*: [mg35021] Working with Strings*From*: bghiggins at ucdavis.edu (Brian Higgins)*Date*: Thu, 20 Jun 2002 02:13:18 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Hi Mathgroup, In a webMathematica application I need to process string information. The essential problem is as follows. The user selects chemical species such as species1 = "cis-3-hexene"; species2 = "acetone"; Ideally these strings need to be processed into a list by using AppendTo to obtain mystring = {"cis-3-hexene", "acetone"}. Then finally this list has to be converted to a string to be passed by the web browser for another 'session', as follows In[13]:=ToString[mystring] Out[13]="{cis-3-hexene, acetone}" The problem is that in the new session I need to convert this string back to a Mathematica expression for further processing, and when I do this the data get corrupted: In[14]:=ToExpression[ToString[mystring]] Out[14]={-3 + cis - hexene, acetone} I have figured a way around this problem but it is in my opinion obtuse and I am looking for a more direct way to handle my problem. Any thoughts? Here is the way I handle it now. Instead of using AppendTo I create the string for passing to the browser as follows ClearAttributes[Plus, Orderless] specieslist = ToString[species1 + species2] (Note the order is important) In the new session this string is processed with the following function stringList[mylist_] := Module[{aa}, aa = DeleteCases[Characters[mylist], x_ /; x == " ", Infinity] //. {x1___, "+", x2___} :> {{x1}, {x2}}; Cases[aa, {x__String} :> StringJoin[x], Infinity]] In[16]:=stringList[specieslist] Out[16]={"cis-3-hexene", "acetone"} Thanks in advance for any help you can offer, Brian