Re: [stack] Cat Type Inference

chris glur <[email protected]> wrote:
> A perhaps trivial question [which also serves to test if my - via
> gmail - posts get through] is: "is it obvious why one would
> want to 'infer the types' ?"

Maybe not.

There are many languages that do very little typechecking at compile
time. They include concatenative languages like Forth, Joy, and
Postscript; people have worked with them for years. The problem is
that many errors you can make in them are incredibly hard to narrow
down and find, but very easy to make. You'd think that with just a
little tiny bit of static checking you could prevent a huge, annoying
class of problems from ever becoming an error.

The problem then becomes that the programmer has to tell the compiler
all about the types of the programs he wants to write, even though
"types" are not what programming is supposed to be about.

Type Inferencing makes the compiler do a bit of work to figure out
what the programmer meant, assuming that the programmer wanted to
write a program that behaves consistently and predictably. As a bonus,
not only does the programmer NOT have to explain all the types to the
compiler, the programmer also gets an error from the compiler if his
program isn't going to behave consistently and predictably.

> == Chris Glur.

-Billy