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[Daniele Filaretti <dfilaretti AT gmail.com>]

Thanks Dwight and Grigore for your answers. 

I will have a look at Dwight's Python semantics, and see if I find some 
inspiration! 

Cheers,
Daniele

On 1 Feb 2013, at 14:00, "Rosu, Grigore" 
<grosu AT illinois.edu>
 wrote:

> Thanks Dwight, but let's face it: we cannot prolong this for too long 
> anymore, we need to provide full lexing support in the tool.  SDF already 
> does it, so it is only a matter of wrapping it up.  Radu, we can use the 
> syntax that we discussed a couple of months ago, something like this if I 
> remember correctly:
> 
>  syntax MyID ::= Token("[A-Za-z$#][0-9A-Za-Z]*")
> 
> This should not be too hard to support, although I let Radu speak for that, 
> because there are several parsers that need to be convinced to work.
> 
> Grigore
> 
> 
> 
> ________________________________________
> From: 
> k-user-bounces AT cs.uiuc.edu
>  
> [k-user-bounces AT cs.uiuc.edu]
>  on behalf of Guth, Dwight 
> [dguth2 AT illinois.edu]
> Sent: Friday, February 01, 2013 7:41 AM
> To: Daniele Filaretti; 
> k-user AT cs.uiuc.edu
> Subject: Re: [K-user] resolving variable names inside double quoted strings 
> (as in PHP)
> 
> I actually just implemented a very similar feature in my python semantics 
> concerning str.format. As part of that I implemented some custom string 
> processing functions that you may find useful. It allowed me to very 
> cleanly iterate through the string, pause at each escape character, and 
> write a rule that customizes the behavior for each one. You are welcome to 
> take a look at it as soon as I push my commit upstream later today to 
> http://code.google.com/p/k-python-semantics/source/browse/python-semantics-strings.k
> 
> If you like the solution you're free to use as much or as little of my code 
> as you want. You're free to ask me any questions you have about the code 
> too.
> 
> Daniele Filaretti 
> <dfilaretti AT gmail.com>
>  wrote:
> 
> 
> Hi all,
> 
> In PHP (the language I'm trying to define in K) when a variable name occurs 
> in a string (variable names always start with $) the value of that variable 
> is found in the environment and printed into the string. For example:
> 
>> $x = "Daniele";
>> echo "Hello $x!"
>> 
>> out>> "Hello Daniele!"
> 
> Until now I ignored this in my definition - i.e., I'm using builtin strings 
> that K offer, and I can achieve the same with (that is also legal in PHP):
> 
>> $x = "Daniele";
>> echo "Hello " . $x . "!"
>> 
>> out>> "Hello Daniele!"
> 
> However, I noticed that the feature is heavily used (of course, as it's a 
> very handy shortcut), so I decided to add it.
> 
> I'm currently having a look at the C definition by Chucky Ellison, as I 
> think something similar has to be done for C's 'printf". However, it seems 
> that their solution is very low level (scanning a string character by 
> character and defining some kind of state machine I guess), and perhaps I 
> don't need that level of detail.
> 
> Ideally, all I need is just something like a string tokenizer.
> For example if my string is
> 
>> "Hello $x!"
> 
> I would like to obtain a list (containing strings and variables) :
> 
>> ["Hello", $x, "!"]
> 
> with this list I could easily print the elements that are already strings, 
> and evaluate the variable names before printing them as well (using my 
> already defined printing function for strings -- sending to it the elements 
> of my list one by one).
> 
> Any ideas? Comments? Suggestions?
> 
> Thanks a lot to everyone!
> 
> Cheers,
> Daniele
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