Opportunities for D

[Jacob Carlborg via Digitalmars-d]

On 09/07/14 00:21, bearophile wrote:

> 9. Built-in tuples usable in all the most important situations (with a
> syntax that doesn't kill possible future improvements of the switch
> statement to perform basic pattern matching on structs that have an
> optional method named "unapply").

I think it would be possible to implement pattern matching in library 
code. Something like this:

match!(value,
     (int t) => ifInt(),
     (char t) => ifChar(),
     () => noOtherMatch()
);

Destructing a type could look something like this:

match(value,
     (type!(Foo), int a, int b) => doSomething(), // match if value is 
of type Foo and extract it
     (int a, int b) => doSomething() // match anything that can be 
destructed to two ints
);

The syntax is not so pretty but I think it would be possible.

-- 
/Jacob Carlborg