whatever I do, things get slower and bigger

[Robert Fraser]

Bill Baxter wrote:
> BCS wrote:
>> I'm working on my parser generator and trying to shoe horn it into a 
>> smaller memory foot print. One approach I'm trying, is to replace 
>> recursive templates with CTFE function and string mixins. This is in 
>> an effort to reduce the number of types that get declared (mostly I'm 
>> using struct templates). The problem is that the CTFE functions seem 
>> to actually use MORE ram than the templates do. I've tried a number of 
>> things like converting to an O(n log n) concatenation system rather 
>> than a O(n^2) and other such tricks but everything seems to be going 
>> backwards. Any advice? (D v1 BTW) I can post code if anyone cares 
>> (it's kind of large: 1.2KLOC, takes a while to compile: ~6min, and use 
>> a lot of RAM: ~2GB).
>>
>> (after a bit more fiddling)
>>
>> I've got it down to 1GB of ram (Yeah!). My conclusions: don't build 
>> strings with CTFE unless it's a lot harder to do it with templates. It 
>> seems that CTFE is a bigger memory hog than templates even with 
>> temples memoizing everything into the symbol tables.
>>
>>
> 
> Yes I believe Don has previously reported that CTFE manipulations on 
> strings basically *never* free the intermediate strings.  Basically the 
> CTFE engine needs a garbage collector (or equiv).
> 
> --bb

grep for 'delete' in the front-end code. It's not there very much :-).