• Stefan Monnier's avatar
    Use a dedicated type to represent interpreted-function values · f2bccae2
    Stefan Monnier authored
    Change `function` so that when evaluating #'(lambda ...)
    we return an object of type `interpreted-function` rather than
    a list starting with one of `lambda` or `closure`.
    The new type reuses the existing PVEC_CLOSURE (nee PVEC_COMPILED)
    tag and tries to align the corresponding elements:
    
    - the arglist, the docstring, and the interactive-form go in the
      same slots as for byte-code functions.
    - the body of the function goes in the slot used for the bytecode string.
    - the lexical context goes in the slot used for the constants of
      bytecoded functions.
    
    The first point above means that `help-function-arglist`,
    `documentation`, and `interactive-form`s don't need to
    distinguish interpreted and bytecode functions any more.
    
    Main benefits of the change:
    
    - We can now reliably distinguish a list from a function value.
    - `cl-defmethod` can dispatch on `interactive-function` and `closure`.
      Dispatch on `function` also works now for interpreted functions but still
      won't work for functions represented as lists or as symbols, of course.
    - Function values are now self-evaluating.  That was alrready the case
      when byte-compiled, but not when interpreted since
      (eval '(closure ...)) signals a void-function error.
      That also avoids false-positive warnings about "don't quote your lambdas"
      when doing things like `(mapcar ',func ...)`.
    
    * src/eval.c (Fmake_interpreted_closure): New function.
    (Ffunction): Use it and change calling convention of
    `Vinternal_make_interpreted_closure_function`.
    (FUNCTIONP, Fcommandp, eval_sub, funcall_general, funcall_lambda)
    (Ffunc_arity, lambda_arity): Simplify.
    (funcall_lambda): Adjust to new representation.
    (syms_of_eval): `defsubr` the new function.  Remove definition of `Qclosure`.
    
    * lisp/emacs-lisp/cconv.el (cconv-make-interpreted-closure):
    Change calling convention and use `make-interpreted-closure`.
    
    * src/data.c (Fcl_type_of): Distinguish `byte-code-function`s from
    `interpreted-function`s.
    (Fclosurep, finterpreted_function_p): New functions.
    (Fbyte_code_function_p): Don't be confused by `interpreted-function`s.
    (Finteractive_form, Fcommand_modes): Simplify.
    (syms_of_data): Define new type symbols and `defsubr` the two
    new functions.
    
    * lisp/emacs-lisp/cl-print.el (cl-print-object) <interpreted-function>:
    New method.
    
    * lisp/emacs-lisp/oclosure.el (oclosure): Refine the parent
    to be `closure`.
    (oclosure--fix-type, oclosure-type): Simplify.
    (oclosure--copy, oclosure--get, oclosure--set): Adjust to
    new representation.
    
    * src/callint.c (Fcall_interactively): Adjust to new representation.
    
    * src/lread.c (bytecode_from_rev_list):
    
    * lisp/simple.el (function-documentation):
    * lisp/help.el (help-function-arglist): Remove the old `closure` case
    and adjust the byte-code case so it handles `interpreted-function`s.
    
    * lisp/emacs-lisp/cl-preloaded.el (closure): New type.
    (byte-code-function): Add it as a parent.
    (interpreted-function): Adjust parent (the type itself was already
    added earlier by accident).
    
    * lisp/emacs-lisp/bytecomp.el (byte-compile--reify-function): Adjust to
    new representation.
    (byte-compile): Use `interpreted-function-p`.
    
    * lisp/emacs-lisp/byte-opt.el (byte-compile-inline-expand): Adjust to
    new representation.
    (side-effect-free-fns): Add `interpreted-function-p` and `closurep`.
    
    * src/profiler.c (trace_hash, ffunction_equal): Simplify.
    * lisp/profiler.el (profiler-function-equal): Simplify.
    
    * lisp/emacs-lisp/nadvice.el (advice--interactive-form-1):
    Use `interpreted-function-p`; adjust to new representation; and take
    advantage of the fact that function values are now self-evaluating.
    
    * lisp/emacs-lisp/lisp-mode.el (closure):
    Remove `lisp-indent-function` property.
    
    * lisp/emacs-lisp/disass.el (disassemble-internal): Adjust to
    new representation.
    * lisp/emacs-lisp/edebug.el (edebug--strip-instrumentation):
    Use `interpreted-function-p`.
    * lisp/emacs-lisp/comp-common.el (comp-known-type-specifiers):
    Add `closurep` and `interpreted-function-p`.
    
    * test/lisp/help-fns-tests.el (help-fns-test-lisp-defun): Adjust to
    more precise type info in `describe-function`.
    * test/lisp/erc/resources/erc-d/erc-d-tests.el (erc-d--render-entries):
    Use `interpreted-function-p`.
    * test/lisp/emacs-lisp/macroexp-resources/vk.el (vk-f4, vk-f5):
    Don't hardcode function values.
    
    * doc/lispref/functions.texi (Anonymous Functions): Don't suggest that
    function values are lists.  Reword "self-quoting" to reflect the
    fact that #' doesn't return the exact same object.  Update examples
    with the new shape of the return value.
    
    * doc/lispref/variables.texi (Lexical Binding):
    * doc/lispref/lists.texi (Rearrangement):
    * doc/lispref/control.texi (Handling Errors): Update examples to reflect
    new representation of function values.
    f2bccae2