Generator from Enumerable#map

Yusuke_ENDOH · September 19, 2007, 4:20pm

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1.9 e$B$G$O!“e(BEnumerable#map e$B$de(B Enumerable#index
e$B$r%V%m%C%/$J$7$G8F$V$He(B
generator e$B$rJV$9$h$&$G$9$,!”$3$l$Oe(B Object#to_enum
e$B$H2?$+0[$J$k$Ne(B
e$B$G$7$g$&$+!#e(B

$ ./ruby -ve ‘g = [:a, :b, :c].map; loop { p g.next }’
ruby 1.9.0 (2007-09-15 patchlevel 0) [i686-linux]
:a
:b
:c

$ ./ruby -ve ‘g = [:a, :b, :c].index; loop { p g.next }’
ruby 1.9.0 (2007-09-15 patchlevel 0) [i686-linux]
:a
:b
:c

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e$B$N$G$9$,!"$I$&$G$7$g$&$+!#e(B

Enumerator e$B$Ge(B yield
e$B$NJV$jCMAjEv$J$I$r;XDj$G$-$k$J$i0UL#$,$"$j$=$&$G$9!#e(B
e$BNc$($Pe(B Enumerator#value= e$B$He(B #result
e$B$rF~$l$F$3$s$JIw$K!#e(B

g = [1, 2, 3].map
loop { x = g.next; g.value = x * 2 }
p g.result #=> [2, 4, 6]

g = [:a, :b, :c].index
loop { x = g.next; g.value = x == :b }
p g.result #=> 1

Yusuke_ENDOH · September 24, 2007, 7:09pm

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1.9 e$B$G$O!“e(BEnumerable#map e$B$de(B Enumerable#index e$B$r%V%m%C%/$J$7$G8F$V$He(B
generator e$B$rJV$9$h$&$G$9$,!”$3$l$Oe(B Object#to_enum e$B$H2?$+0[$J$k$Ne(B
e$B$G$7$g$&$+!#e(B

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e$B$G$7$g$&$+!#e(B

p g.result #=> 1
e$B$3$N3HD%$,FCJL$KM_$7$$$o$1$G$O$J$$$N$G$9$,!“30It%$%F%l!<%?$re(B fiber
e$B$Ne(B
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Index: enumerator.c

— enumerator.c (revision 13509)
+++ enumerator.c (working copy)
@@ -42,6 +42,8 @@
VALUE method;
VALUE proc;
VALUE args;

VALUE value;
VALUE result;
enum_iter *iter;
VALUE fib;
VALUE dst;
@@ -55,6 +57,8 @@
rb_gc_mark(ptr->method);
rb_gc_mark(ptr->proc);
rb_gc_mark(ptr->args);
rb_gc_mark(ptr->value);
rb_gc_mark(ptr->result);
rb_gc_mark(ptr->fib);
rb_gc_mark(ptr->dst);
}
@@ -238,6 +242,8 @@
ptr->iter = (enum_iter *)rb_yield;
}
if (argc) ptr->args = rb_ary_new4(argc, argv);
ptr->value = Qnil;
ptr->result = Qnil;
ptr->fib = 0;
ptr->dst = Qnil;
ptr->no_next = Qfalse;
@@ -286,6 +292,8 @@
ptr1->proc = ptr0->proc;
ptr1->iter = ptr0->iter;
ptr1->args = ptr0->args;
ptr1->value = ptr0->value;
ptr1->result = ptr0->result;
ptr1->fib = ptr0->fib;

return obj;
@@ -371,8 +379,9 @@
next_ii(VALUE i, VALUE obj)
{
struct enumerator *e = enumerator_ptr(obj);
e->value = Qnil;
rb_fiber_yield(1, &i);

return Qnil;

return e->value;
}

static VALUE
@@ -381,7 +390,7 @@
struct enumerator *e = enumerator_ptr(obj);
VALUE nil = Qnil;

rb_block_call(obj, rb_intern(“each”), 0, 0, next_ii, obj);

e->result = rb_block_call(obj, rb_intern(“each”), 0, 0, next_ii,
obj);
e->no_next = Qtrue;
return rb_fiber_yield(1, &nil);
}
@@ -431,6 +440,36 @@

/*

call-seq:

- e.value = v => v
- Sets the value that current block will return.
*/

+static VALUE
+enumerator_set_value(VALUE obj, VALUE value) {

struct enumerator *e = enumerator_ptr(obj);
e->value = value;
return value;
+}

+/*

- call-seq:
- e.result => object
- Returns the value that the iteration method returned.
*/

+static VALUE
+enumerator_result(VALUE obj) {

struct enumerator *e = enumerator_ptr(obj);
return e->result;
+}

+/*

- call-seq:
- e.next? => e
- Rewinds the enumeration sequence by the next method.
  @@ -467,6 +506,8 @@
  rb_define_method(rb_cEnumerator, “to_splat”, enumerator_to_splat,
  0);
  rb_define_method(rb_cEnumerator, “next”, enumerator_next, 0);
  rb_define_method(rb_cEnumerator, “rewind”, enumerator_rewind, 0);
rb_define_method(rb_cEnumerator, “value=”, enumerator_set_value,
1);
rb_define_method(rb_cEnumerator, “result”, enumerator_result, 0);

rb_eStopIteration = rb_define_class(“StopIteration”,
rb_eIndexError);

Yusuke_ENDOH · September 29, 2007, 5:24pm

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In message “Re: [ruby-dev:31847] Re: generator from Enumerable#map”
on Tue, 25 Sep 2007 02:09:33 +0900, “Yusuke ENDOH” [email protected]
writes:

|> 1.9 e$B$G$O!“e(BEnumerable#map e$B$de(B Enumerable#index e$B$r%V%m%C%/$J$7$G8F$V$He(B
|> generator e$B$rJV$9$h$&$G$9$,!”$3$l$Oe(B Object#to_enum e$B$H2?$+0[$J$k$Ne(B
|> e$B$G$7$g$&$+!#e(B
|
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|e$B$G$7$g$&$+!#e(B

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e$B$KJXMx$@$H;W$C$F$$$k$o$1$G$O$J$$$G$9!#BP>N@-e(B(e$B$H$+D>8r@-e(B)e$B$Oe(B
Rubye$B$N@_7W4p=`$G$OM%@hEY$,Dc$$$N$G!”$J$K$+M}M3$,$“$l$P$=$l$re(B
e$B$R$C$/$j$+$($9$3$H$K0[O@$O$”$j$^$;$s!#e(B

|> Enumerator e$B$Ge(B yield e$B$NJV$jCMAjEv$J$I$r;XDj$G$-$k$J$i0UL#$,$"$j$=$&$G$9!#e(B

|e$B$3$N3HD%$,FCJL$KM_$7$$$o$1$G$O$J$$$N$G$9$,!“30It%$%F%l!<%?$re(B fiber e$B$Ne(B
|e$BBeMQ$H$9$k$?$a$K$OL5$$$HITJX$J$N$G!”;n$7$K<BAu$7$F$_$^$7$?!#e(B
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e$BBe$o$j$K;H$&I,MW$O$J$$$s$8$c$J$$$G$7$g$&$+!#e(B

Yusuke_ENDOH · September 30, 2007, 12:26pm

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|> 1.9 e$B$G$O!“e(BEnumerable#map e$B$de(B Enumerable#index e$B$r%V%m%C%/$J$7$G8F$V$He(B
|> generator e$B$rJV$9$h$&$G$9$,!”$3$l$Oe(B Object#to_enum e$B$H2?$+0[$J$k$Ne(B
|> e$B$G$7$g$&$+!#e(B

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e$B$R$C$/$j$+$($9$3$H$K0[O@$O$"$j$^$;$s!#e(B

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each e$B$G%V%m%C%/$r>JN,$7$?;~e(B generator e$B$rJV$9$J$i!"e(B
map e$B$G%V%m%C%/$r>JN,$7$?;~$be(B generator e$B$rJV$9$Y$-e(B

e$B$H$$$&$3$H$G$7$g$&$+!#$=$3$@$1BP>N$K$7$F$b!"e(Bmap e$B$de(B index
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each e$B$,%V%m%C%/$G$be(B generator e$B$G$b$=$N5!G=$r;H$($k$J$i!"e(B
map e$B$b%V%m%C%/$G$be(B generator e$B$G$b$=$N5!G=$r;H$($k$Y$-e(B

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Yusuke_ENDOH · October 5, 2007, 3:32pm

e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:31916] Re: generator from Enumerable#map”
on Sun, 30 Sep 2007 19:25:42 +0900, “Yusuke ENDOH” [email protected]
writes:

|> e$B0[$J$C$F$$$^$;$s!#$=$NB8:_$KBP>N@-0J30$NM}M3$O$“$j$^$;$s!#FCe(B
|> e$B$KJXMx$@$H;W$C$F$$$k$o$1$G$O$J$$$G$9!#BP>N@-e(B(e$B$H$+D>8r@-e(B)e$B$Oe(B
|> Rubye$B$N@_7W4p=`$G$OM%@hEY$,Dc$$$N$G!”$J$K$+M}M3$,$“$l$P$=$l$re(B
|> e$B$R$C$/$j$+$($9$3$H$K0[O@$O$”$j$^$;$s!#e(B
|
|e$BBP>N@-$N0UL#$,$h$/$o$+$j$^$;$s$,!"e(B
|
| each e$B$be(B map e$B$b%$%F%l!<%H$9$kE@$G;w$F$$$k$+$i!"e(B
| each e$B$G%V%m%C%/$r>JN,$7$?;~e(B generator e$B$rJV$9$J$i!"e(B
| map e$B$G%V%m%C%/$r>JN,$7$?;~$be(B generator e$B$rJV$9$Y$-e(B
|
|e$B$H$$$&$3$H$G$7$g$&$+!#$=$3$@$1BP>N$K$7$F$b!"e(Bmap e$B$de(B index e$B$NK\Mh$Ne(B
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e$B$(!<$H!“!V$J$iMW$i$J$$$N$+$J$”!W$H:n6H$r;O$a$h$&$H$7$F$h$&$de(B
e$B$/;W$$=P$7$^$7$?!#e(Bmape$B$,e(Benumeratore$B$rJV$9$He(B

obj.map.with_index{|x,i|…}

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|
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| each e$B$,%V%m%C%/$G$be(B generator e$B$G$b$=$N5!G=$r;H$($k$J$i!“e(B
| map e$B$b%V%m%C%/$G$be(B generator e$B$G$b$=$N5!G=$r;H$($k$Y$-e(B
|
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Yusuke_ENDOH · October 14, 2007, 6:34pm

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07/10/05 e$B$Ke(B Yukihiro M.[email protected]
e$B$5$s$O=q$-$^$7$?e(B:

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e$B$J$k$[$I!<!“$”$j$,$H$&$4$6$$$^$9!#e(B
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e$B$D$N5!G=$,e(B
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ary.map do … end

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p ary.map do … end

e$B$H=q$-D>$7$F$7$^$C$?$H$$$&$h$/$"$k%_%9$J$N$G!“e(Bmap
e$B$K:a$O$”$j$^$;$s!#e(B

Yusuke_ENDOH · October 15, 2007, 2:38am

e$B$^$D$b$He(B e$B$f$-$R$m$G$9e(B

In message “Re: [ruby-dev:32055] Re: generator from Enumerable#map”
on Mon, 15 Oct 2007 01:33:16 +0900, “Yusuke ENDOH” [email protected]
writes:

|07/10/05 e$B$Ke(B Yukihiro M.[email protected] e$B$5$s$O=q$-$^$7$?e(B:
|> * eache$B$K$be(Bmape$B$K$be(Bwith_indexe$B$,IU$1$i$l$F4r$7$$e(B
|>
|> e$B$H$$$&$N$,K\Ev$NM}M3$G$9!#e(B
|
|e$B$J$k$[$I!<!“$”$j$,$H$&$4$6$$$^$9!#e(B
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|
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|
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|
|p ary.map do … end
|
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