Re: dynamic vs. static typing

[Pascal Costanza <address@hidden>]

Anton van Straaten wrote:

> Pierce has a nice description of the subjective effects of static type
> checks, in TAPL:
> 
>    "In practice, static typechecking exposes a surprisingly broad range of
> errors.  Programmers working in richly typed languages often remark that
> their programs tend to "just work" once they pass the typechecker, much more
> often than they feel they have a right to expect.  One possible explanation
> for this is that not only trivial mental slips [...] but also deeper
> conceptual errors [...] will often manifest as inconsistencies at the level
> of types."
> 
> Anyone who's made serious use of a language with a good static typesystem
> has experienced this.  Think of it as a way to get an entire class of
> high-performance unit tests without having to actually write them.

While it's certainly true that there is a critical mass of people who 
find static type systems liberating and empowering, I recall reading 
statements by people who have made the opposite experience. They have 
found dynamic type systems to be liberating and empowering - and they 
include people who have tried languages with advanced H-M type systems.

So going from a subjective assessment to a claim about "anyone" is not 
valid.


Pascal

-- 
Pascal Costanza               University of Bonn
mailto:costanza@web.de        Institute of Computer Science III
http://www.pascalcostanza.de  Römerstr. 164, D-53117 Bonn (Germany)