有无内置的将 closure 还原为 lambda 的 API? (需要能够递归处理 bindings 的)
如：
(let ((closure-to-lambda
(lambda (x)
`(let ,(mapcar
(lambda (sv)
(list (car sv) (cdr sv)))
(aref x 2))
(lambda ,(aref x 0) ,@(aref x 1))))))
(funcall
closure-to-lambda
(let ((a 1)) (lambda nil a))))
;; => (let ((a 1)) (lambda nil a))
#+name: 2025-07-30-19-34
#+begin_src emacs-lisp :eval yes :lexical t
(!let (ic2l)
(!def ic2l
(lambda (ic &optional new-env)
(cond
;; do convertion only when `ic' is
;; an interpreted-closure.
((and (interpreted-function-p ic)
(closurep ic))
(let ((args (aref ic 0))
(body (aref ic 1))
(env (aref ic 2))
(docstring
(when (length> ic 4) (aref ic 4)))
(iform
(when (length> ic 5) (aref ic 5))))
(when iform
(setq body `(,iform ,@body)))
(when docstring
(setq body `(,docstring ,@body)))
(if (equal '(t) env)
`(lambda ,args ,@body)
`(let ,(mapcar
(lambda (sv)
`(,(car sv)
;; replace variable with new
;; environment if required.
,(or
(alist-get (car sv) new-env)
(ic2l (cdr sv) new-env))))
env)
(lambda ,args ,@body)))))
(t ic))))
ic2l)
#+end_src
#+name: 2025-07-30-21-06
#+begin_src emacs-lisp :lexical t
(!def '!import
(!let (!import (ic2l (make-symbol "ic2l")))
(!def !import
(lambda (path &optional bindings)
;; 除了 (car (last path)) 可能指向 symbol 或
;; closure 外，其他都应该指向 closure.
(!let (env sym val first fi-prev-sym)
(setq first (car path))
(setq sym first)
(setq path (cdr path))
(setq val (symbol-function sym))
(while (and path (closurep val)
(interpreted-function-p val))
(setq env (aref val 2))
(setq sym (car path))
(setq path (cdr path))
;; 从 env 中，找到 symbol sym 所对应的
;; closure.
(cond
((and
(setq val (alist-get sym env))
(cond
((and (closurep val)
(interpreted-function-p val))
t)
;; function indirection
((symbolp val)
(while (and val (symbolp val))
(setq fi-prev-sym val)
(setq val (symbol-function val)))
(cond
((and (closurep val)
(interpreted-function-p val))
t)
;; 这是一个特殊分支，只为内部使用：
;; (!def (!import '(!import ic2l)) ...)
((and (null val) (null path)
(eq first '!import))
(setq val fi-prev-sym)))))))
(t (setq val nil))))
(when path (error "Not found %S" path))
(if (or (null bindings) (symbolp val)) val
;; '((s1 v1)(s2 v2)) =>
;; '((s1 . v1)(s2 . v2))
(setq env
(mapcar
(lambda (sv)
(cons (car sv) (cadr sv)))
bindings))
;; eval lambda sexp with new environment.
(eval (ic2l val env) env)))))
!import))
#+end_src
!import 的使用场景：
#+begin_src emacs-lisp :lexical t :eval no
;; -*- lexical-binding: t; -*-
(!def 'package-A
(!let (package-A log say-hi)
(!def log
(!let ((name "[A]"))
(lambda (fmt &rest args)
(apply
#'message
(concat name fmt) args))))
(!def say-hi (lambda () (log "hi")))
(!def package-A
(lambda (&rest args)
(ignore say-hi log)
(!import `(package-A ,@args))))
package-A))
(!def 'package-B
(!let (package-B
;; reuse `log' function of
;; package-A, but change it's
;; name to ours.
(log (!import '(package-A log)
'((name "[B]"))))
say-hi)
(!def say-hi (lambda () (log "hi")))
(!def package-B
(lambda (&rest args)
(ignore say-hi)
(!import `(package-B ,@args))))
package-B))
(!let ((say-hi (package-A 'say-hi)))
(say-hi)) ; => "[A]hi"
(!let ((say-hi (package-B 'say-hi)))
(say-hi)) ; => "[B]hi"
#+end_src
一种将 lambda 的构造工作委派给其他函数的方法：
#+begin_src emacs-lisp :eval no
(defmacro !fn (&rest cdr)
(declare (indent defun))
(!let* ((body (cdr cdr))
;; skip docstring.
(body (if (stringp (car body))
(cdr body)
body))
;; skip interactive form.
(body (if (eq (car-safe (car body))
'interactive)
(cdr body)
body))
decl gtor)
(cond
((and
;; 试找 declare
(when (eq (car-safe (car body))
'declare)
(setq decl (car body)))
;; 试找 declare 中的 '(!fn gtor)
(catch 'break
(mapcar
(lambda (spec)
(when (eq (car-safe spec) '!fn)
;; 让 gtor 决定如何生成 lambda
(setq gtor (cadr spec))
(when (and (symbolp gtor)
(not (functionp gtor)))
(setq gtor (intern-soft
(format
"!fn-%S" gtor))))
(when (functionp gtor)
(throw 'break (gtor cdr)))))
decl)
nil)))
(t `(lambda ,@cdr)))))
#+end_src
!fn 的使用场景
根据给定 Org链接 指向的代码块构造 lambda.
在这里，我们稍微对 Org代码块 做个区分。当前，我们将其划分为三类：A类 是 elisp 代码片段；B类 是 elisp lambda; C类 是非 elisp 语言的代码块。
举例说明：
A类：
#+name: 2025-08-03-20-38
#+begin_src emacs-lisp :var args='("a" "b") :results silent
(apply #'concat args)
#+end_src
B类：
#+name: 2025-08-03-20-39
#+begin_src emacs-lisp :var args='("a" "b") :results silent
(lambda (&rest args)
(apply #'concat args))
#+end_src
C类：
#+name: 2025-08-03-20-40
#+begin_src python python :var args='("a" "b") :results silent
from functools import reduce
return reduce(lambda a,b:a+b, args)
#+end_src
#+name: 2025-08-03-20-41
#+begin_src C++ :var args='("a" "b") :includes '(<string> <iostream>)
std::string c = "";
for (int i = 0; i < sizeof(args)/sizeof(const char *); ++i)
{
c += std::string(args[i]);
}
std::cout << c;
#+end_src
借助 !fn 和几个工具函数，我们可以实现从 Org代码块 加载 lambda:
(!let (s+ r)
(!def s+
(!fn (&rest args)
(declare (!fn wrap-org-src-block))
[[2025-08-03-20-38]]))
(push (s+ "a" "b" "c") r)
(!def s+
(!fn (&rest args)
(declare (!fn from-org-src-block))
[[2025-08-03-20-39]]))
(push (s+ "a" "b" "c") r)
(!def s+
(!fn (&rest args)
(declare (!fn by-org-src-block))
[[2025-08-03-20-40]]))
(push (s+ "a" "b" "c") r)
(!def s+
(!fn (&rest args)
(declare (!fn by-org-src-block))
[[2025-08-03-20-41]]))
(push (s+ "a" "b" "c") r)
r)
;; => ("abc" "abc" "abc" "abc")
于是，我们可以很容易地从其他语言引入一些东西，比如，从 python 中引入矩阵乘法：
#+name: 2025-08-03-21-03
#+begin_src python :var a='((1) (2)) b='(3 4) :results silent
import numpy as np
a = np.mat(a)
b = np.mat(b)
c = a @ b
return c.tolist()
#+end_src
(!let ((m* (!fn (a b)
(declare (!fn by-org-src-block))
[[2025-08-03-21-03]])))
(m*
'((1 2 3)(4 5 6))
'((7 8 9 10)(11 12 13 14)(15 16 17 18))))
;; => ((74 80 86 92) (173 188 203 218))
实现
针对 A, B, C类，我们分别用如下的三个工具函数生成 lambda:
A类：
#+name: 2025-08-03-20-33
#+begin_src emacs-lisp :eval no :lexical t
(!def '!fn-wrap-org-src-block
(lambda (cdr)
(unless (fboundp 'org-noweb-expand-link)
(error
"!fn-wrap-org-src-block: %s"
"`org-noweb-expand-link' no found."))
(read
(format
"(lambda %S %s)"
(car cdr)
(org-noweb-expand-link
(format "%s" (car (last cdr))))))))
#+end_src
B类：
#+name: 2025-08-03-20-34
#+begin_src emacs-lisp :eval no :lexical t
(!def '!fn-from-org-src-block
(lambda (cdr)
(unless (fboundp 'org-noweb-expand-link)
(error
"!fn-from-org-src-block: %s"
"`org-noweb-expand-link' no found."))
(read
(org-noweb-expand-link
(format "%s" (car (last cdr)))))))
#+end_src
C类：
#+name: 2025-08-03-20-35
#+begin_src emacs-lisp :eval no :lexical t
(!def '!fn-by-org-src-block
(lambda (cdr)
(unless (fboundp 'org-exec)
(error
"!fn-by-org-src-block: %s"
"`org-exec' no found."))
`(lambda ,(car cdr)
(org-exec
,(car (last cdr)) nil
:eval "yes" :results "none"
,@(apply
#'append
(mapcar
(lambda (a)
(if (eq a '&rest) nil
`(',a `(identity ',,a))))
(car cdr)))))))
#+end_src