[m-users.] String comparison when compiling to C

[Sean Charles (emacstheviking)]

Thank Zoltan.

I am now using `ordering` in and `compare` for my code. I also have now found '3.5 The standard ordering' chapter and read it.
Again, apologies for the noise, in my defence, chemotherapy followed by radiotherapy comes with a few side effects, fortunately one of them is liking Mercury more and more and making me hate my day job as a Django developer even worse :D haha

Thanks again,
Sean. (I think that's who I am...)


> On 23 Aug 2024, at 12:35, Zoltan Somogyi <zoltan.somogyi at runbox.com> wrote:
> 
> 
> 
> On Fri, 23 Aug 2024 12:15:24 +0100, "Sean Charles (emacstheviking)" <objitsu at gmail.com> wrote:
>> % The builtin comparison operation on strings is also implementation
>> % dependent. The current implementation performs string comparison using
>> %
>> % - C's strcmp() function, when compiling to C;
> 
>> So what is the 'way' to do string comparisons?
> 
> The compare predicate in the builtin module. That is what your initial quote
> is referring to.
> 
>> I find it odd in all the code I've written, I have never needed to do this before!
> 
> Most of the time, when people compare strings in other languages,
> they do it to implement operations such as maps from strings to other entities,
> or sorting. In Mercury, the standard library provides all the usual such operations.
> And since those operations are generic, i.e. they operate on values of any type,
> their implementations use the generic compare predicate in the builtin module,
> not type-specific operations such as < or >.
> 
> Zoltan.
> 
>