[ragel-users] Re: Help with extracting a list of numbers

Manoj Rajagopalan ma... at nanorex.com
Wed Mar 26 00:02:19 UTC 2008


Hi Adrian

    The detection works only when I enter a space at the end. And yes, 
the terminating 0 is being sent. Hope this isn't a bug. Maybe I'm 
missing something really simple.

    I'm using Ragel 6.0 on Fedora 8.

    BTW, I'm attaching a small C++ program if anyone would like to run it.

    In the program, it prints out the ending character (*pe) and 
confirms that it is '\0'. Should 'pe' point to the last char or to one 
past it, i.e., is the character range [p,pe] or [p, pe) ?

    In one place in the manual I see p+strlen(buf) (fig 5.1, pg 36) 
whereas in another I see p+strlen(buf)+1 (pg 6)


-- Manoj


Adrian Thurston wrote:
> Hi Manoj,
> 
> Are you sure the null is being sent to the parser? If it is then
> printNumber should be executed on the last character.
> 
> Adrian
> 
> Manoj Rajagopalan wrote:
>> Hi all,
>>
>>    I'm trying to write a pattern to extract a list of numbers following 
>> the keyword bond and I'm not able to figure out why my pattern below 
>> always skips the last number
>>
>>    My input is of the form:
>>
>>    bond <number> <number> ...
>>
>> %%{
>>      machine bond_parser;
>>
>>      whole_number = digit+    >to{intVal=0;}   ${intVal = intVal*10 + 
>> (fc-'0');}    ;
>>
>>      main :=
>>          space* 'bond'
>>          (space+ whole_number %printNumber)+
>>          space* 0;
>> }%%
>>
>> where printNumber is an action to print the number just updated into the 
>> integer variable intVal.
>>
>> The 0 at the end of the pattern is the NULL character that cin.getline() 
>> adds when reading upto the newline character from the console.
>>
>> I realize this may be due to the leaving action for the last number that 
>> never gets called but could someone tell me a way around this?
>>
>> Thanks,
>> Manoj
>>
> 
> > 
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