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Comment by BoingBoomTschak | Hacker News Reader

>God, Lisp...the core language isn't exactly that interesting in this day-and-age. Dynamic typing, garbage collection, anonymous functions, this has been the bread-and-butter of Python, JS, Ruby, etc.

CL still got symbols, the reader (and its macros), gradual typing and user available runtime compilation (compile and compile-file).

I find the core language itself near perfect (mostly the historic stuff like threads/atomics/unicode missing, the whole divide between normal CL and CLOS and lack of recursive and parametric typing") but the standard library quite baroque and lacking; still infinitely more serviceable than C's, though.

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(to be clear those historic stuff are present in today's implementations)

> CL still got symbols, the reader (and its macros), gradual typing and user available runtime compilation (compile and compile-file).

TypeScript has all of these, too.

who is using macros in ts ?

Really? You can `(compile nil my-lambda)` without having to write a JIT yourself?

I meant reader macros, by the way: can it do that?

  ; A comment
  (set-macro-character #\% (get-macro-character #\;))
  % Also a comment

I must admit, I don't know what this is doing, and why.

The semi-colon symbol is the single-line comment symbol in Lisp, but the percent symbol means nothing special in Lisp.

SET-MACRO-CHARACTER is used to modify what happens when certain characters are found while reading code. In this case, SET-MACRO-CHARACTER is being used to instruct Lisp to start treating % as if it were a semi-colon (i.e. the third line is a comment), thus extending the syntax of Lisp on-the-fly.

The (GET-MACRO-CHARACTER #\;) portion could have been any code at all; GP could have defined % to do anything, such as "treat the remainder of this line as if it were a line of Python code", using calls to a Python implementation, such as cl-python [0].

[0] = <https://github.com/metawilm/cl-python>

Sure.

    new Function(“…”)

There’s no guarantee that it will be JITed, but then the CL standard is also pretty loose about the semantics of ‘compile’.

JS Symbols are like CL gensym and CL symbols (interned strings) don't exist in JS.

Normal TS doesn't expose normal macros or reader macros to the user.

JS runtimes don't have the image introspection ability of CL.

TS types are removed before the JIT and don't actually impact performance (not to mention they encourage polymorphism which is actively BAD for JS performance). CL type hints are use by the compiler to actually speed up the output code (quite dramatically I'd add).

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