Are you *sure* you know what “dynamic typing” is ? How does explicit typing system differ from implicit ? Why can a typing system be strong and weak ?

I had some knowledge of this stuff, but it wasn’t really organized in my head (bet most of you feel the same). Today I found this on Lambda the Ultimate:

There are a lot of choices when designing a type system

Strong vs Weak

Strong: Impossible to treat an object as an wrong type

Weak: Possible to use improper operations on an object

Static vs Dynamic

Static: The type of an expression is known at compile time.

Dynamic: The type of an expression is only known at run time.

Explicit vs Implicit

Explicit: All variables and functions are explicitly typed (also called Manifest typing)

Implicit: The types of variables are implicit (also called Latent typing)

Many people argue ardently about this stuff while they don’t really understand the terms. I paste it here just to remember it

Related posts:

1. A taxonomy of typing systems
2. Programming language typing - a big mishmash
3. Reading C type declarations
4. Lisp on one hand, Ada on the other
5. SICP section 2.4

This entry was posted on Wednesday, September 3rd, 2003 at 10:32 pm and is filed under Programming. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.