A Haskell Programmer Tries to Learn Racket

Next, enable the lisp/scheme modules in prelude-modules.el [1]. You need the Evil plugin to get Vim modal editing and probably Evil Leader (so you get Vim style commands).

You can look at my config [2], there's nothing really funny except I map Ctrl-H to backspace and Ctrl-[ to ESC as that's what I also use in my Vim. There's also a slight modification to make Smartparens make parenthesis highlighting behave like in Vim.

One other thing is if you're in insert mode then Emacs keystrokes should also work (Ctrl-Z to force switching between Vim/Emacs keystrokes).

If you install the SICP plugin for Emacs (it's in my custom.el) and you type M-x info-display-manual sicp, or if you have Evil installed you can use use Vim's command :info-display-manual sicp, you'll get the SICP book as a manual inside Emacs.

[1] https://github.com/humana/dotfiles/blob/master/emacs/prelude... [2] https://github.com/humana/dotfiles/blob/master/emacs/persona...

What is a "systems person", in this case? I guess it makes sense if you know who it was who said this, but I don't. Is it a programmer working with code for servers?

http://en.wikipedia.org/wiki/First-class_data_type

Hash-tables are part of the standard, and available in conforming implementations out-of-the-box. (make-hash-table) produces an instance of a table which can be passed as argument to function, be assigned to variables, ... I don't think syntax defines what feature is or isn't first-class, even though it has an impact on it's usage.

Adding support for litteral hash-tables is possible, as it was already said: define a reader macro; that macro could even simply use the utility function "plist-hash-table", from Alexandria, which is used like this:

     (alexandria:plist-hash-table '(:a 1 :b 2))

On the first hand, people say that CL is bloated, but on the other hand, they want to have everything available by default. Do you expect Python or C++ implementations to come with regular expression built-in, or is it okay if you need to add an 'import' statement or link with Boost?

CL allows you to define libraries that can change even the basic surface syntax, for your convenience. Considering that there is more than enough defined in the specification, what benefits would be in having an "official" hash litteral syntax? consistency accross different projects? many people use the "cl-ppcre" regex library without problem.

Yes, regular expressions come in a library even though they could easily be labelled as a fundamental feature of a language, and hence be expected to be "first-class", or "built-in"; but again, that is not the case in CL, which is neither Perl nor Lua.

And about keyword parameters, this is just the surface syntax, which is on purpose based on a simple, basic representation of the syntax tree as lists of expressions.

Then, the compiler will work with the argument list in your function definition and take one or another approach to represent them in the object code. And I doubt that they are stored in a hash-table, which is unlikely an appropriate way to handle a couple of keyword arguments.

Similarly, when you define a class, everything is declared by a simple list of slots, where slots are lists of parameters: but in fact, the class might store the actual instance slots in a hash-table, an array, a list, a database or a memory mapped file.

The fact that you are mainly manipulating lists does not mean that everything is eventually represented as supposedly inefficient linked-list at runtime.

Fair enough, pretend I said "first class syntactic object."

> CL allows you to define libraries that can change even the basic surface syntax, for your convenience. Considering that there is more than enough defined in the specification, what benefits would be in having an "official" hash litteral syntax?

Reader macros are powerful, no doubt. The benefit of building this into a language would mainly be syntactic regularity. CL as it stands has keyword args, alists, property lists, and real hash tables (probably amongst other things I don't know about), that all fill basically the same purpose of mapping names to values. If the creators of Common Lisp and its parent lisps had started with hash tables with standard reader syntax, they probably wouldn't have felt the need to introduce so many subtly different but conceptually identical concepts. Lua, for instance, uses its single table data structure both as syntax and as an internal representation for pretty much any case where it needs to map some names to some values; from keyword arguments to environments to "metatables" that provide fairly powerful metaprogramming support, they're all just tables that you can write literally and use the same functions to manipulate. You could say that alists fill this purpose and are even more syntactically regular since they're still sexps, but then why doesn't CL use alists for keyword args, and why don't Scheme's keyword arg extensions use alist syntax? Historical accident, or are alists just ugly? If you can admit that they're a little too ugly and verbose to include in function calls, then maybe you can see why I don't like writing alist literals.

> The fact that you are mainly manipulating lists does not mean that everything is eventually represented as supposedly inefficient linked-list at runtime.

I'm well aware that a compiler can easily expand keyword arguments into regular ones. I strongly doubt your compiler will transform all the literal alists in your program into hash tables, and replace all the alist-ref functions and so on operating on them with the equivalent hash table functions. As long as alists are more syntactically blessed than hash tables, people will use them where another data structure would be more appropriate.