Re:Practical Common Lisp (2005)
by lispm on Monday December 05, 2016 @06:19AM
(#13104725)
>People can build amazing programs with just Vectors or Hashes. People can build amazing programs without understanding recursion,
evaluation, macros, or metalinguistic abstraction.
That's what Common Lisp provided back in 1984. Basic data structures like strings, characters, vectors, various numbers, I/O streams, records and hashes. It offer a lot of Lisp-stuff additionally, but it had everything to write plain programs.
> recursion was a negative, not a positive
That's why real-world Common Lisp usually avoided recursion early on and Common Lisp has lots of non-recursive iteration facilities. Scheme made some forms of recursion 'cheap' by introducing tail call optimisation (TCO) - which often is provided by Common Lisp implementations, too. But TCO was not standardised because it was difficult to integrate it with the rest of the language back then.
> I do not remember any discussion of Hashes, Vectors, etc.,
There were some books with more interesting examples, like the then popular LISP from Winston/Horn, where the 3rd edition from 1989 was fully moved to Common Lisp.
For key-value data structures Lisp traditionally used property lists, association lists and forms of search trees. Later some forms of object systems, which also map keys to values - like Frame systems. Larger Lisp systems used hash arrays (Interlisp) or hash tables (Common Lisp). Hash-tables were indeed not that often topic in the literature.
> CLtL and R4RS are references
The CLtL1 was quite good for learning Common Lisp. It's an nicely readable book and not the dense R4RS. CLtL2 made thinks difficult, because it was presenting the then defined ANSI CL (before it was actually finished) and all the deltas to the older CLtL1.
That's what Common Lisp provided back in 1984. Basic data structures like strings, characters, vectors, various numbers, I/O streams, records and hashes. It offer a lot of Lisp-stuff additionally, but it had everything to write plain programs.
> recursion was a negative, not a positive
That's why real-world Common Lisp usually avoided recursion early on and Common Lisp has lots of non-recursive iteration facilities. Scheme made some forms of recursion 'cheap' by introducing tail call optimisation (TCO) - which often is provided by Common Lisp implementations, too. But TCO was not standardised because it was difficult to integrate it with the rest of the language back then.
> I do not remember any discussion of Hashes, Vectors, etc.,
There were some books with more interesting examples, like the then popular LISP from Winston/Horn, where the 3rd edition from 1989 was fully moved to Common Lisp.
For key-value data structures Lisp traditionally used property lists, association lists and forms of search trees. Later some forms of object systems, which also map keys to values - like Frame systems. Larger Lisp systems used hash arrays (Interlisp) or hash tables (Common Lisp). Hash-tables were indeed not that often topic in the literature.
> CLtL and R4RS are references
The CLtL1 was quite good for learning Common Lisp. It's an nicely readable book and not the dense R4RS. CLtL2 made thinks difficult, because it was presenting the then defined ANSI CL (before it was actually finished) and all the deltas to the older CLtL1.