From: Yehuda Katz <wycats@...>
Date: 2008-11-16T07:16:43+09:00
Subject: [ruby-core:19955] Re: Proposal: Method#get_args

Agreed. What we need is a special sentinel value (I originally  
proposed Method::EXPRESSION)

Sent from my iPhone

On Nov 15, 2008, at 12:53 PM, Nobuyoshi Nakada <nobu@ruby-lang.org>  
wrote:

> Hi,
>
> At Sun, 16 Nov 2008 00:48:54 +0900,
> Yukihiro Matsumoto wrote in [ruby-core:19942]:
>> |I guess so.  I'd like to make sure two more things:
>> |
>> |  * symbol for block argument should be :block, or anything else?
>> |  * if you don't have a rest argument name, you will get [:rest],  
>> ok?
>>
>> One more:
>>
>>> def foo(a, b = 1, *c, d)
>>> => [[:req, :a], [:opt, :b, 1], [:rest, :c], [:req, :d]]
>>
>> what if the default value for an optional argument is more than a  
>> simple
>> literal?   :expr as Austine mentioned in [ruby-core:19882]?  Or drop
>> default values altogether?
>
> Since :expr is a valid expression, I don't think it is
> reasonable.
>
> 
> Index: iseq.c
> ===================================================================
> --- iseq.c    (revision 20237)
> +++ iseq.c    (working copy)
> @@ -1275,4 +1275,67 @@ rb_iseq_clone(VALUE iseqval, VALUE newcb
> }
>
> +static VALUE
> +simple_default_value(const VALUE *seq)
> +{
> +    VALUE val;
> +    switch (*seq++) {
> +      case BIN(putnil):
> +    val = Qnil;
> +      case BIN(putobject):
> +    val = *seq++;
> +    if (*seq == BIN(setlocal)) break;
> +      default:
> +    return Qundef;
> +    }
> +    return val;
> +}
> +
> +VALUE
> +rb_iseq_parameters(const rb_iseq_t *iseq)
> +{
> +    int i, r, s;
> +    VALUE a, args = rb_ary_new2(iseq->arg_size);
> +    ID req, opt, rest, block;
> +#define PARAM_TYPE(type) rb_ary_push(a = rb_ary_new2(2),  
> ID2SYM(type))
> +#define PARAM_ID(i) iseq->local_table[i]
> +#define PARAM(i, type) (              \
> +    PARAM_TYPE(type),              \
> +    rb_id2name(PARAM_ID(i)) ?          \
> +    rb_ary_push(a, ID2SYM(PARAM_ID(i))) : \
> +    a)
> +
> +    CONST_ID(req, "req");
> +    for (i = 0; i < iseq->argc; i++) {
> +    rb_ary_push(args, PARAM(i, req));
> +    }
> +    r = iseq->arg_rest != -1 ? iseq->arg_rest :
> +    iseq->arg_post_len > 0 ? iseq->arg_post_start :
> +    iseq->arg_block != -1 ? iseq->arg_block :
> +    iseq->arg_size;
> +    CONST_ID(opt, "opt");
> +    for (s = i; i < r; i++) {
> +    PARAM_TYPE(opt);
> +    if (rb_id2name(PARAM_ID(i))) {
> +        VALUE defval = simple_default_value(iseq->iseq + iseq- 
> >arg_opt_table[i-s]);
> +        rb_ary_push(a, ID2SYM(PARAM_ID(i)));
> +        if (defval != Qundef) rb_ary_push(a, defval);
> +    }
> +    rb_ary_push(args, a);
> +    }
> +    if (iseq->arg_rest != -1) {
> +    CONST_ID(rest, "rest");
> +    rb_ary_push(args, PARAM(iseq->arg_rest, rest));
> +    }
> +    r = iseq->arg_post_start + iseq->arg_post_len;
> +    for (i = iseq->arg_post_start; i < r; i++) {
> +    rb_ary_push(args, PARAM(i, req));
> +    }
> +    if (iseq->arg_block != -1) {
> +    CONST_ID(block, "block");
> +    rb_ary_push(args, PARAM(iseq->arg_block, block));
> +    }
> +    return args;
> +}
> +
> /* ruby2cext */
>
> Index: proc.c
> ===================================================================
> --- proc.c    (revision 20237)
> +++ proc.c    (working copy)
> @@ -26,7 +26,10 @@ VALUE rb_cBinding;
> VALUE rb_cProc;
>
> +VALUE rb_iseq_parameters(const rb_iseq_t *iseq);
> +
> static VALUE bmcall(VALUE, VALUE);
> static int method_arity(VALUE);
> static VALUE rb_obj_is_method(VALUE m);
> +static rb_iseq_t *get_method_iseq(VALUE method);
>
> /* Proc */
> @@ -616,6 +619,12 @@ get_proc_iseq(VALUE self)
>     GetProcPtr(self, proc);
>     iseq = proc->block.iseq;
> -    if (!RUBY_VM_NORMAL_ISEQ_P(iseq))
> -    return 0;
> +    if (!RUBY_VM_NORMAL_ISEQ_P(iseq)) {
> +    NODE *node = (NODE *)iseq;
> +    iseq = 0;
> +    if (nd_type(node) == NODE_IFUNC && node->nd_cfnc == bmcall) {
> +        /* method(:foo).to_proc */
> +        iseq = get_method_iseq(node->nd_tval);
> +    }
> +    }
>     return iseq;
> }
> @@ -651,4 +660,40 @@ rb_proc_location(VALUE self)
> }
>
> +static VALUE
> +unnamed_parameters(int arity)
> +{
> +    VALUE a, param = rb_ary_new2((arity < 0) ? -arity : arity);
> +    int n = (arity < 0) ? ~arity : arity;
> +    ID req, rest;
> +    CONST_ID(req, "req");
> +    a = rb_ary_new3(1, ID2SYM(req));
> +    OBJ_FREEZE(a);
> +    for (; n; --n) {
> +    rb_ary_push(param, a);
> +    }
> +    if (arity < 0) {
> +    CONST_ID(rest, "rest");
> +    rb_ary_store(param, ~arity, rb_ary_new3(1, ID2SYM(rest)));
> +    }
> +    return param;
> +}
> +
> +/*
> + * call-seq:
> + *    proc.parameters  => array
> + *
> + * returns the parameter information of this proc
> + */
> +
> +static VALUE
> +rb_proc_parameters(VALUE self)
> +{
> +    rb_iseq_t *iseq = get_proc_iseq(self);
> +    if (!iseq) {
> +    return unnamed_parameters(proc_arity(self));
> +    }
> +    return rb_iseq_parameters(iseq);
> +}
> +
> /*
>  * call-seq:
> @@ -1461,4 +1506,6 @@ get_method_iseq(VALUE method)
>     body = data->body;
>     switch (nd_type(body)) {
> +      case NODE_BMETHOD:
> +    return get_proc_iseq(body->nd_cval);
>       case RUBY_VM_METHOD_NODE:
>    GetISeqPtr((VALUE)body->nd_body, iseq);
> @@ -1485,4 +1532,21 @@ rb_method_location(VALUE method)
>
> /*
> + * call-seq:
> + *    meth.parameters  => array
> + *
> + * returns the parameter information of this method
> + */
> +
> +static VALUE
> +rb_method_parameters(VALUE method)
> +{
> +    rb_iseq_t *iseq = get_method_iseq(method);
> +    if (!iseq) {
> +    return unnamed_parameters(method_arity(method));
> +    }
> +    return rb_iseq_parameters(iseq);
> +}
> +
> +/*
>  *  call-seq:
>  *   meth.to_s      =>  string
> @@ -1812,4 +1876,5 @@ Init_Proc(void)
>     rb_define_method(rb_cProc, "curry", proc_curry, -1);
>     rb_define_method(rb_cProc, "source_location", rb_proc_location,  
> 0);
> +    rb_define_method(rb_cProc, "parameters", rb_proc_parameters, 0);
>
>     /* Exceptions */
> @@ -1847,4 +1912,5 @@ Init_Proc(void)
>     rb_define_method(rb_cMethod, "unbind", method_unbind, 0);
>     rb_define_method(rb_cMethod, "source_location",  
> rb_method_location, 0);
> +    rb_define_method(rb_cMethod, "parameters",  
> rb_method_parameters, 0);
>     rb_define_method(rb_mKernel, "method", rb_obj_method, 1);
>     rb_define_method(rb_mKernel, "public_method",  
> rb_obj_public_method, 1);
> @@ -1865,4 +1931,5 @@ Init_Proc(void)
>     rb_define_method(rb_cUnboundMethod, "bind", umethod_bind, 1);
>     rb_define_method(rb_cUnboundMethod, "source_location",  
> rb_method_location, 0);
> +    rb_define_method(rb_cUnboundMethod, "parameters",  
> rb_method_parameters, 0);
>
>     /* Module#*_method */
> Index: test/ruby/test_proc.rb
> ===================================================================
> --- test/ruby/test_proc.rb    (revision 20237)
> +++ test/ruby/test_proc.rb    (working copy)
> @@ -674,3 +674,46 @@ class TestProc < Test::Unit::TestCase
>     assert_equal([1,2,[3],4,5], r, "[ruby-core:19485]")
>   end
> +
> +  def test_parameters
> +    assert_equal([], proc {}.parameters)
> +    assert_equal([], proc {||}.parameters)
> +    assert_equal([[:req, :a]], proc {|a|}.parameters)
> +    assert_equal([[:req, :a], [:req, :b]], proc {|a, b|}.parameters)
> +    assert_equal([[:opt, :a, :a], [:block, :b]], proc {|a=:a,  
> &b|}.parameters)
> +    assert_equal([[:req, :a], [:opt, :b, :b]], proc {|a,  
> b=:b|}.parameters)
> +    assert_equal([[:rest, :a]], proc {|*a|}.parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:block, :c]], proc {|a,  
> *b, &c|}.parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c]], proc {|a,  
> *b, c|}.parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c],  
> [:block, :d]], proc {|a, *b, c, &d|}.parameters)
> +    assert_equal([[:req, :a], [:opt, :b, :b], [:rest, :c],  
> [:req, :d], [:block, :e]], proc {|a, b=:b, *c, d, &e|}.parameters)
> +    assert_equal([[:req], [:block, :b]], proc {|(a), &b|}.parameters)
> +    assert_equal([[:req, :a], [:req, :b], [:opt, :c, :c],  
> [:opt, :d, :d], [:rest, :e], [:req, :f], [:req, :g], [:block, :h]],  
> proc {|a,b,c=:c,d=:d,*e,f,g,&h|}.parameters)
> +  end
> +
> +  def pm0() end
> +  def pm1(a) end
> +  def pm2(a, b) end
> +  def pmo1(a = :a, &b) end
> +  def pmo2(a, b = :b) end
> +  def pmo3(*a) end
> +  def pmo4(a, *b, &c) end
> +  def pmo5(a, *b, c) end
> +  def pmo6(a, *b, c, &d) end
> +  def pmo7(a, b = :b, *c, d, &e) end
> +  def pma1((a), &b) end
> +
> +
> +  def test_bound_parameters
> +    assert_equal([], method(:pm0).to_proc.parameters)
> +    assert_equal([[:req, :a]], method(:pm1).to_proc.parameters)
> +    assert_equal([[:req, :a], [:req, :b]],  
> method(:pm2).to_proc.parameters)
> +    assert_equal([[:opt, :a, :a], [:block, :b]],  
> method(:pmo1).to_proc.parameters)
> +    assert_equal([[:req, :a], [:opt, :b, :b]],  
> method(:pmo2).to_proc.parameters)
> +    assert_equal([[:rest, :a]], method(:pmo3).to_proc.parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:block, :c]],  
> method(:pmo4).to_proc.parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c]],  
> method(:pmo5).to_proc.parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c],  
> [:block, :d]], method(:pmo6).to_proc.parameters)
> +    assert_equal([[:req, :a], [:opt, :b, :b], [:rest, :c],  
> [:req, :d], [:block, :e]], method(:pmo7).to_proc.parameters)
> +    assert_equal([[:req], [:block, :b]],  
> method(:pma1).to_proc.parameters)
> +  end
> end
> Index: test/ruby/test_method.rb
> ===================================================================
> --- test/ruby/test_method.rb    (revision 20237)
> +++ test/ruby/test_method.rb    (working copy)
> @@ -21,4 +21,6 @@ class TestMethod < Test::Unit::TestCase
>   def mo5(a, *b, c) end
>   def mo6(a, *b, c, &d) end
> +  def mo7(a, b = nil, *c, d, &e) end
> +  def ma1((a), &b) end
>
>   class Base
> @@ -222,3 +224,71 @@ class TestMethod < Test::Unit::TestCase
>     assert_raise(ArgumentError) { o.method(:foo).call(1) }
>   end
> +
> +  define_method(:pm0) {||}
> +  define_method(:pm1) {|a|}
> +  define_method(:pm2) {|a, b|}
> +  define_method(:pmo1) {|a = nil, &b|}
> +  define_method(:pmo2) {|a, b = nil|}
> +  define_method(:pmo3) {|*a|}
> +  define_method(:pmo4) {|a, *b, &c|}
> +  define_method(:pmo5) {|a, *b, c|}
> +  define_method(:pmo6) {|a, *b, c, &d|}
> +  define_method(:pmo7) {|a, b = nil, *c, d, &e|}
> +  define_method(:pma1) {|(a), &b|}
> +
> +  def test_bound_parameters
> +    assert_equal([], method(:m0).parameters)
> +    assert_equal([[:req, :a]], method(:m1).parameters)
> +    assert_equal([[:req, :a], [:req, :b]], method(:m2).parameters)
> +    assert_equal([[:opt, :a, nil], [:block, :b]],  
> method(:mo1).parameters)
> +    assert_equal([[:req, :a], [:opt, :b, nil]],  
> method(:mo2).parameters)
> +    assert_equal([[:rest, :a]], method(:mo3).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:block, :c]],  
> method(:mo4).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c]],  
> method(:mo5).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c],  
> [:block, :d]], method(:mo6).parameters)
> +    assert_equal([[:req, :a], [:opt, :b, nil], [:rest, :c],  
> [:req, :d], [:block, :e]], method(:mo7).parameters)
> +    assert_equal([[:req], [:block, :b]], method(:ma1).parameters)
> +  end
> +
> +  def test_unbound_parameters
> +    assert_equal([], self.class.instance_method(:m0).parameters)
> +    assert_equal([[:req, :a]],  
> self.class.instance_method(:m1).parameters)
> +    assert_equal([[:req, :a], [:req, :b]],  
> self.class.instance_method(:m2).parameters)
> +    assert_equal([[:opt, :a, nil], [:block, :b]],  
> self.class.instance_method(:mo1).parameters)
> +    assert_equal([[:req, :a], [:opt, :b, nil]],  
> self.class.instance_method(:mo2).parameters)
> +    assert_equal([[:rest, :a]],  
> self.class.instance_method(:mo3).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:block, :c]],  
> self.class.instance_method(:mo4).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c]],  
> self.class.instance_method(:mo5).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c],  
> [:block, :d]], self.class.instance_method(:mo6).parameters)
> +    assert_equal([[:req, :a], [:opt, :b, nil], [:rest, :c],  
> [:req, :d], [:block, :e]],  
> self.class.instance_method(:mo7).parameters)
> +    assert_equal([[:req], [:block, :b]],  
> self.class.instance_method(:ma1).parameters)
> +  end
> +
> +  def test_bmethod_bound_parameters
> +    assert_equal([], method(:pm0).parameters)
> +    assert_equal([[:req, :a]], method(:pm1).parameters)
> +    assert_equal([[:req, :a], [:req, :b]], method(:pm2).parameters)
> +    assert_equal([[:opt, :a, nil], [:block, :b]],  
> method(:pmo1).parameters)
> +    assert_equal([[:req, :a], [:opt, :b, nil]],  
> method(:pmo2).parameters)
> +    assert_equal([[:rest, :a]], method(:pmo3).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:block, :c]],  
> method(:pmo4).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c]],  
> method(:pmo5).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c],  
> [:block, :d]], method(:pmo6).parameters)
> +    assert_equal([[:req, :a], [:opt, :b, nil], [:rest, :c],  
> [:req, :d], [:block, :e]], method(:pmo7).parameters)
> +    assert_equal([[:req], [:block, :b]], method(:pma1).parameters)
> +  end
> +
> +  def test_bmethod_unbound_parameters
> +    assert_equal([], self.class.instance_method(:pm0).parameters)
> +    assert_equal([[:req, :a]],  
> self.class.instance_method(:pm1).parameters)
> +    assert_equal([[:req, :a], [:req, :b]],  
> self.class.instance_method(:pm2).parameters)
> +    assert_equal([[:opt, :a, nil], [:block, :b]],  
> self.class.instance_method(:pmo1).parameters)
> +    assert_equal([[:req, :a], [:opt, :b, nil]],  
> self.class.instance_method(:pmo2).parameters)
> +    assert_equal([[:rest, :a]],  
> self.class.instance_method(:pmo3).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:block, :c]],  
> self.class.instance_method(:pmo4).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c]],  
> self.class.instance_method(:pmo5).parameters)
> +    assert_equal([[:req, :a], [:rest, :b], [:req, :c],  
> [:block, :d]], self.class.instance_method(:pmo6).parameters)
> +    assert_equal([[:req, :a], [:opt, :b, nil], [:rest, :c],  
> [:req, :d], [:block, :e]],  
> self.class.instance_method(:pmo7).parameters)
> +    assert_equal([[:req], [:block, :b]],  
> self.class.instance_method(:pma1).parameters)
> +  end
> end
> 
>
> -- 
> Nobu Nakada
>