Re: shiny uno version, Desktop IDL

On 06/19/2012 11:27 AM, Bjoern Michaelsen wrote:
> On Tue, Jun 19, 2012 at 10:42:39AM +0200, Stephan Bergmann wrote:
> > On 06/14/2012 01:58 PM, Bjoern Michaelsen wrote:
> > Actually writing down the static information can have a huge benefit
> > on maintainability.  (Even in static languages with type inference
> > like Haskell, where you would not actually need to write down type
> > signatures, it is common practice to nevertheless do so especially
> > for exported entities, for better documentation.)  Witness gbuild:
> > we do run into cases there where a macro is called with more
> > arguments than it expects, and at least I often need to decipher
> > definitions (or worse, use "monkey see, monkey do" copy/paste) to
> > figure out what arguments, and in what order, a macro takes.  I
> > would *love* to have a more statically typed machinery there...
>
> The problem with gbuild is not that it is dynamic typed, but that it is weakly
> typed (everything is a string).

While gbuild indeed only has a single basic data type (string), it does 
have the notion of functions (aka macros) that take arguments, so it 
does have more elaborate types, namely "string* -> string" (i.e., a 
macro takes an arbitrary number of string arguments and produces a 
single result string).  What I was complaining about is that it does not 
have more specific types like "(string, string, string) -> string" 
(i.e., a macro that takes exactly three string arguments).

Literature often calls gbuild's "everything is a string" design 
"type-unsafe" rather than "weakly typed" (then again, nomenclature is 
certainly inconsistent in this field).

> Testing an Any to be of a type able to provide what it
> should at runtime is still a sane thing to do, and is done anyway most of the
> time.

It is the minimum of what one needs to be done, I'd say.  ;)  (Or I 
maybe don't get what you want to say here exactly.)  What I'm arguing is 
that having to resort to runtime checking is needed rarely, so I 
wouldn't make dynamic typing the default.

Stephan