Re: How to get struct's members ?

[bioinfornatics via Digitalmars-d-learn]

On Friday, 23 May 2014 at 08:20:05 UTC, Philippe Sigaud via
Digitalmars-d-learn wrote:

On Fri, May 23, 2014 at 8:44 AM, monarch_dodra via Digitalmars-d-learn

<digitalmars-d-learn@puremagic.com> wrote:

On Friday, 23 May 2014 at 01:17:18 UTC, bioinfornatics wrote:

I would like to get struct's members and zip them with an action

tupleof will do what you need (mostly). However, I don't think there will be any way to (generically) run-time zip on the members, due to probably type mismatch, and memory layout. In any case, nothing trivial, AFAIK.

You can define a map-like (or zip-like) template to act on tuples as if they were ranges, but the resulting type will still be a tuple: in general, the members and the delegates associated with them will all

have a different type.

Bioinfornatics, if you know your struct members are all of the same type, you can 'cast' the tuple as an array by wrapping it in square

brackets like this:

[ myStruct.tupleof ]

and then use the usual range algorithms.

If that's not the case, you can create another struct, holding both

the original struct and the delegates...

I did some generic range-like work on tuples a few years ago. See for example:

https://github.com/PhilippeSigaud/dranges/blob/master/tuple.d#L620

Could you explain what you want with more details?

I would like to create a generic parser for simple case.
User provide a sructure to fill:
struct A {
    string a;
    string b
}

In another way they are a struct whicg describe how to get start
and end section.



alias predicate = bool delegate( immutable(ubyte)[] );

struct Statement
{
      immutable bool delegate( immutable(ubyte)[] ) start;
      immutable bool delegate( immutable(ubyte)[] ) end;
      immutable bool isOptional;

      @safe nothrow
      this( in predicate start, in predicate end, isOptional =
false )
      {
          this.start      = start;
          this.end        = end;
          this.isOptional = isOptional;
      }

}

Like this you could say members a start by @ and end by a newline

Statement sequenceLine          = Statement(
                                                  ( word ) =>
word[0] >= 'A' && word[0]  <= 'z',
                                                  ( word ) =>
word[0] == '\n' );

Once all section are delimited give them to eat to a parser. You
have not to write a parser for each new file format