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Comment by lispm | Hacker News Reader

many Lisp systems record the source location and/or the source itself (especially a source level interpreter needs that)

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Do you mind enumerating what those systems are? I've only played around with Allegro CL and SBCL myself.

Maybe collectively we can. In Emacs/SLIME/CCL,SBCL on ARM32,x86-64 ESC + '.' (command 'find-tag') on a symbol in the REPL opens a buffer with the definition of that symbol, provided you have the sources (it's neither decompiling nor reading the definition from the binary, but follows a hint to the source file). So this is more functionality of the environment / tools, rather then the compiler or language. Works beautifully though and in most cases you don't really want the sources embedded within the binary.

> So this is more functionality of the environment / tools, rather then the compiler or language.

Doesn't FUNCTION-LAMBDA-EXPRESSION apply here?

Didn't even know about this one. It is one of those 'optional' features -- the standard puts it like "Any implementation may legitimately return nil as the lambda-expression of any function." And indeed, CCL choses to do just that. SBCL seems to put in some effort to decompile the function.

Worst case scenario, you can probably patch your compiler's COMPILE function to store the data somewhere before performing the actual compilation.

As for CCL, it seems to work for me just fine as long as you set CCL:*SAVE-DEFINITIONS* to T:

    Clozure Common Lisp Version 1.12.1 (v1.12.1) LinuxX8664

    For more information about CCL, please see http://ccl.clozure.com.

    CCL is free software.  It is distributed under the terms of the Apache
    Licence, Version 2.0.
    ? (defun foobar (a b c) (* a (+ b c)))
    FOOBAR
    ? (function-lambda-expression #'foobar)
    NIL
    NIL
    FOOBAR
    ? (setf ccl:*save-definitions* t)
    T
    ? (defun foobar (a b c) (* a (+ b c)))
    FOOBAR
    ? (function-lambda-expression #'foobar)
    (LAMBDA (A B C) (DECLARE (CCL::GLOBAL-FUNCTION-NAME FOOBAR)) (BLOCK FOOBAR (* A (+ B C))))
    NIL
    FOOBAR

CCL has a feature called source-note to record locations and source.

Not a Common Lisp implementation but Clojure can find the source for a symbol (provided the source code file is in the classpath) with the clojure.repl/source function (doc: https://clojure.github.io/clojure/clojure.repl-api.html#cloj... .) All development environments support jump to definition.

LispWorks for example has a documented and extensible mechanism to record the locations of definitions:

http://www.lispworks.com/documentation/lw80/lw/lw-dspecs-ug....

Common Lisp has standard function FUNCTION-LAMBDA-EXPRESSION:

  * (defun foo (a)
      (my-if (> a 10) 'big 'small))
  FOO

  * (function-lambda-expression #'foo)
  (LAMBDA (A) (BLOCK FOO (MY-IF (> A 10) 'BIG 'SMALL)))
  T
  FOO

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