Scheme or Common Lisp?

Yes, it's a “which programming language to leran ???” thread, but this time it's ...more specific I guess?

So I already know C ^{_{and Perl}} and wish to acquaint myself with other paradigms than the procedural and object-oriented ones I've become uncomfortably familiar with (i.e., functional). I also intend to learn Haskell at some point in the future in order to complete the holy trinity of syntaxes.

So, /anus/. Regarding the thread title, what are the differences that you find make you prefer one Lisp dialect to another? Is there even much of a difference? Or did you just choose one as your way of saying, “I've read SICP”?

>>34
No, what is prohibited in the standard (but actually allowed by most implementations, some even make it easier) is changing the value or rebinding it (of symbols in CL).

However, nothing prevents you from making another package and doing a shadowing import or merely, not importing some symbols from the CL package (symbols for you you can provide definitions, and the definitions you make can call the original ones).

The major reasoning for disallowing such things are:
1) You're changing the behaviour of code you didn't write and the functionality of other code may become unreliable/non-standard compliant
2) Even if you change the definition of a function, that function can be already inlined, or changing one macro definition won't change the expansions of already compiled code.

Of course, using packages to pick what symbols you like (and thus features) is perfectly permitted and that's what most people do when they want to change the behaviour of some symbols in the CL package portably.