# String parsing?

**URL:** <https://rubytalk.org/t/string-parsing/21884>\
**Category:** ruby-talk\
**Created:** [25 October 2005 19:32 UTC](https://rubytalk.org/t/string-parsing/21884 "2005-10-25T19:32:58Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![Michael\_Zanis](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Michael\_Zanis](https://rubytalk.org/u/Michael_Zanis)\
**Post date:** [25 October 2005 19:32 UTC](https://rubytalk.org/t/string-parsing/21884/1 "2005-10-25T19:32:58Z")

</div>

Hi,

I am new to ruby but have an okay background in perl. I am trying to parse  
a string into an array.

string = (foo:0.05,bar:0.115);

I would like the array to look like this:

Array[0] = (  
Array[1] = foo  
Array[2] = 0.05  
Array[3] = ,  
Array[4] = bar  
Array[5] = 0.115  
Array[6] = )  
Array[7] = ;

I have a rather clunky perl script for this, but in learning ruby I thought  
I might see if there is an elegant way to parse this string using tokens.  
Thank you for any help you might have.

-M

---

<div class="post-metadata">

**Author:** ![James\_Edward\_Gray\_II](https://avatars.discourse-cdn.com/v4/letter/j/ea5d25/32.png) [@James\_Edward\_Gray\_II](https://rubytalk.org/u/James_Edward_Gray_II)\
**Post date:** [25 October 2005 19:42 UTC](https://rubytalk.org/t/string-parsing/21884/2 "2005-10-25T19:42:34Z")

</div>

> Hi,
> 
> I am new to ruby but have an okay background in perl. I am trying to parse  
> a string into an array.
> 
> string = (foo:0.05,bar:0.115);
> 
> I would like the array to look like this:
> 
> Array[0] = (  
> Array[1] = foo  
> Array[2] = 0.05  
> Array[3] = ,  
> Array[4] = bar  
> Array[5] = 0.115  
> Array[6] = )  
> Array[7] = ;

See if this helps:

\>\> "(foo:0.05,bar:0.115);".scan(/[a-z]+|\d+\.\d+|[(,);]/)  
=\> ["(", "foo", "0.05", ",", "bar", "0.115", ")", ";"]

James Edward Gray II

> **···**
>
> On Oct 25, 2005, at 2:32 PM, Michael Zanis wrote:

---

<div class="post-metadata">

**Author:** ![Eric\_Mahurin1](https://avatars.discourse-cdn.com/v4/letter/e/34f0e0/32.png) [@Eric\_Mahurin1](https://rubytalk.org/u/Eric_Mahurin1)\
**Post date:** [25 October 2005 20:00 UTC](https://rubytalk.org/t/string-parsing/21884/3 "2005-10-25T20:00:02Z")

</div>

This may be an overkill, but take a look at my grammar project:

[http://rubyforge.org/projects/grammar/](http://rubyforge.org/projects/grammar/)

You can build a lexer (what you want) and/or a parser with ruby  
syntax that looks kind of like BNF.

But keep in mind the above is only the first release. I'm  
building a ruby parser/lexer right now and doing this is  
revealing various holes and inconsistencies in the API. The  
basics of the API will remain unchanged though: "+" create a  
sequence (from 2 grammars) and "|" will create an alternation  
(from 2 grammars). The basic idea is that you start with base  
grammar objects and you build more complex grammar objects  
using various methods to combine or morph them.

> **···**
>
> --- Michael Zanis \<mzanis@purdue.edu\> wrote:
> 
> > Hi,
> > 
> > I am new to ruby but have an okay background in perl. I am  
> > trying to parse  
> > a string into an array.
> > 
> > string = (foo:0.05,bar:0.115);
> > 
> > I would like the array to look like this:
> > 
> > Array[0] = (  
> > Array[1] = foo  
> > Array[2] = 0.05  
> > Array[3] = ,  
> > Array[4] = bar  
> > Array[5] = 0.115  
> > Array[6] = )  
> > Array[7] = ;
> > 
> > I have a rather clunky perl script for this, but in learning  
> > ruby I thought  
> > I might see if there is an elegant way to parse this string  
> > using tokens.  
> > Thank you for any help you might have.
> > 
> > -M
> 
> \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_  
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