/************************************************ enumerator.c - provides Enumerator class $Author$ Copyright (C) 2001-2003 Akinori MUSHA $Idaemons: /home/cvs/rb/enumerator/enumerator.c,v 1.1.1.1 2001/07/15 10:12:48 knu Exp $ $RoughId: enumerator.c,v 1.6 2003/07/27 11:03:24 nobu Exp $ $Id$ ************************************************/ #include "internal.h" /* * Document-class: Enumerator * * A class which allows both internal and external iteration. * * An Enumerator can be created by the following methods. * - Kernel#to_enum * - Kernel#enum_for * - Enumerator.new * * Most methods have two forms: a block form where the contents * are evaluated for each item in the enumeration, and a non-block form * which returns a new Enumerator wrapping the iteration. * * enumerator = %w(one two three).each * puts enumerator.class # => Enumerator * * enumerator.each_with_object("foo") do |item, obj| * puts "#{obj}: #{item}" * end * * # foo: one * # foo: two * # foo: three * * enum_with_obj = enumerator.each_with_object("foo") * puts enum_with_obj.class # => Enumerator * * enum_with_obj.each do |item, obj| * puts "#{obj}: #{item}" * end * * # foo: one * # foo: two * # foo: three * * This allows you to chain Enumerators together. For example, you * can map a list's elements to strings containing the index * and the element as a string via: * * puts %w[foo bar baz].map.with_index { |w, i| "#{i}:#{w}" } * # => ["0:foo", "1:bar", "2:baz"] * * An Enumerator can also be used as an external iterator. * For example, Enumerator#next returns the next value of the iterator * or raises StopIteration if the Enumerator is at the end. * * e = [1,2,3].each # returns an enumerator object. * puts e.next # => 1 * puts e.next # => 2 * puts e.next # => 3 * puts e.next # raises StopIteration * * You can use this to implement an internal iterator as follows: * * def ext_each(e) * while true * begin * vs = e.next_values * rescue StopIteration * return $!.result * end * y = yield(*vs) * e.feed y * end * end * * o = Object.new * * def o.each * puts yield * puts yield(1) * puts yield(1, 2) * 3 * end * * # use o.each as an internal iterator directly. * puts o.each {|*x| puts x; [:b, *x] } * # => [], [:b], [1], [:b, 1], [1, 2], [:b, 1, 2], 3 * * # convert o.each to an external iterator for * # implementing an internal iterator. * puts ext_each(o.to_enum) {|*x| puts x; [:b, *x] } * # => [], [:b], [1], [:b, 1], [1, 2], [:b, 1, 2], 3 * */ VALUE rb_cEnumerator; VALUE rb_cLazy; static ID id_rewind, id_each, id_new, id_initialize, id_yield, id_call, id_size, id_to_enum; static ID id_eqq, id_next, id_result, id_lazy, id_receiver, id_arguments, id_memo, id_method, id_force; static VALUE sym_each, sym_cycle; VALUE rb_eStopIteration; struct enumerator { VALUE obj; ID meth; VALUE args; VALUE fib; VALUE dst; VALUE lookahead; VALUE feedvalue; VALUE stop_exc; VALUE size; VALUE procs; rb_enumerator_size_func *size_fn; }; static VALUE rb_cGenerator, rb_cYielder; struct generator { VALUE proc; VALUE obj; }; struct yielder { VALUE proc; }; typedef struct MEMO *lazyenum_proc_func(VALUE, struct MEMO *, VALUE, long); typedef VALUE lazyenum_size_func(VALUE, VALUE); typedef struct { lazyenum_proc_func *proc; lazyenum_size_func *size; } lazyenum_funcs; struct proc_entry { VALUE proc; VALUE memo; const lazyenum_funcs *fn; }; static VALUE generator_allocate(VALUE klass); static VALUE generator_init(VALUE obj, VALUE proc); /* * Enumerator */ static void enumerator_mark(void *p) { struct enumerator *ptr = p; rb_gc_mark(ptr->obj); rb_gc_mark(ptr->args); rb_gc_mark(ptr->fib); rb_gc_mark(ptr->dst); rb_gc_mark(ptr->lookahead); rb_gc_mark(ptr->feedvalue); rb_gc_mark(ptr->stop_exc); rb_gc_mark(ptr->size); rb_gc_mark(ptr->procs); } #define enumerator_free RUBY_TYPED_DEFAULT_FREE static size_t enumerator_memsize(const void *p) { return sizeof(struct enumerator); } static const rb_data_type_t enumerator_data_type = { "enumerator", { enumerator_mark, enumerator_free, enumerator_memsize, }, 0, 0, RUBY_TYPED_FREE_IMMEDIATELY }; static struct enumerator * enumerator_ptr(VALUE obj) { struct enumerator *ptr; TypedData_Get_Struct(obj, struct enumerator, &enumerator_data_type, ptr); if (!ptr || ptr->obj == Qundef) { rb_raise(rb_eArgError, "uninitialized enumerator"); } return ptr; } static void proc_entry_mark(void *p) { struct proc_entry *ptr = p; rb_gc_mark(ptr->proc); rb_gc_mark(ptr->memo); } #define proc_entry_free RUBY_TYPED_DEFAULT_FREE static size_t proc_entry_memsize(const void *p) { return p ? sizeof(struct proc_entry) : 0; } static const rb_data_type_t proc_entry_data_type = { "proc_entry", { proc_entry_mark, proc_entry_free, proc_entry_memsize, }, }; static struct proc_entry * proc_entry_ptr(VALUE proc_entry) { struct proc_entry *ptr; TypedData_Get_Struct(proc_entry, struct proc_entry, &proc_entry_data_type, ptr); return ptr; } /* * call-seq: * obj.to_enum(method = :each, *args) -> enum * obj.enum_for(method = :each, *args) -> enum * obj.to_enum(method = :each, *args) {|*args| block} -> enum * obj.enum_for(method = :each, *args){|*args| block} -> enum * * Creates a new Enumerator which will enumerate by calling +method+ on * +obj+, passing +args+ if any. * * If a block is given, it will be used to calculate the size of * the enumerator without the need to iterate it (see Enumerator#size). * * === Examples * * str = "xyz" * * enum = str.enum_for(:each_byte) * enum.each { |b| puts b } * # => 120 * # => 121 * # => 122 * * # protect an array from being modified by some_method * a = [1, 2, 3] * some_method(a.to_enum) * * It is typical to call to_enum when defining methods for * a generic Enumerable, in case no block is passed. * * Here is such an example, with parameter passing and a sizing block: * * module Enumerable * # a generic method to repeat the values of any enumerable * def repeat(n) * raise ArgumentError, "#{n} is negative!" if n < 0 * unless block_given? * return to_enum(__method__, n) do # __method__ is :repeat here * sz = size # Call size and multiply by n... * sz * n if sz # but return nil if size itself is nil * end * end * each do |*val| * n.times { yield *val } * end * end * end * * %i[hello world].repeat(2) { |w| puts w } * # => Prints 'hello', 'hello', 'world', 'world' * enum = (1..14).repeat(3) * # => returns an Enumerator when called without a block * enum.first(4) # => [1, 1, 1, 2] * enum.size # => 42 */ static VALUE obj_to_enum(int argc, VALUE *argv, VALUE obj) { VALUE enumerator, meth = sym_each; if (argc > 0) { --argc; meth = *argv++; } enumerator = rb_enumeratorize_with_size(obj, meth, argc, argv, 0); if (rb_block_given_p()) { enumerator_ptr(enumerator)->size = rb_block_proc(); } return enumerator; } static VALUE enumerator_allocate(VALUE klass) { struct enumerator *ptr; VALUE enum_obj; enum_obj = TypedData_Make_Struct(klass, struct enumerator, &enumerator_data_type, ptr); ptr->obj = Qundef; return enum_obj; } static VALUE enumerator_init(VALUE enum_obj, VALUE obj, VALUE meth, int argc, const VALUE *argv, rb_enumerator_size_func *size_fn, VALUE size) { struct enumerator *ptr; rb_check_frozen(enum_obj); TypedData_Get_Struct(enum_obj, struct enumerator, &enumerator_data_type, ptr); if (!ptr) { rb_raise(rb_eArgError, "unallocated enumerator"); } ptr->obj = obj; ptr->meth = rb_to_id(meth); if (argc) ptr->args = rb_ary_new4(argc, argv); ptr->fib = 0; ptr->dst = Qnil; ptr->lookahead = Qundef; ptr->feedvalue = Qundef; ptr->stop_exc = Qfalse; ptr->size = size; ptr->size_fn = size_fn; return enum_obj; } /* * call-seq: * Enumerator.new(size = nil) { |yielder| ... } * Enumerator.new(obj, method = :each, *args) * * Creates a new Enumerator object, which can be used as an * Enumerable. * * In the first form, iteration is defined by the given block, in * which a "yielder" object, given as block parameter, can be used to * yield a value by calling the +yield+ method (aliased as +<<+): * * fib = Enumerator.new do |y| * a = b = 1 * loop do * y << a * a, b = b, a + b * end * end * * p fib.take(10) # => [1, 1, 2, 3, 5, 8, 13, 21, 34, 55] * * The optional parameter can be used to specify how to calculate the size * in a lazy fashion (see Enumerator#size). It can either be a value or * a callable object. * * In the second, deprecated, form, a generated Enumerator iterates over the * given object using the given method with the given arguments passed. * * Use of this form is discouraged. Use Kernel#enum_for or Kernel#to_enum * instead. * * e = Enumerator.new(ObjectSpace, :each_object) * #-> ObjectSpace.enum_for(:each_object) * * e.select { |obj| obj.is_a?(Class) } #=> array of all classes * */ static VALUE enumerator_initialize(int argc, VALUE *argv, VALUE obj) { VALUE recv, meth = sym_each; VALUE size = Qnil; if (rb_block_given_p()) { rb_check_arity(argc, 0, 1); recv = generator_init(generator_allocate(rb_cGenerator), rb_block_proc()); if (argc) { if (NIL_P(argv[0]) || rb_respond_to(argv[0], id_call) || (RB_TYPE_P(argv[0], T_FLOAT) && RFLOAT_VALUE(argv[0]) == INFINITY)) { size = argv[0]; } else { size = rb_to_int(argv[0]); } argc = 0; } } else { rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS); rb_warn("Enumerator.new without a block is deprecated; use Object#to_enum"); recv = *argv++; if (--argc) { meth = *argv++; --argc; } } return enumerator_init(obj, recv, meth, argc, argv, 0, size); } /* :nodoc: */ static VALUE enumerator_init_copy(VALUE obj, VALUE orig) { struct enumerator *ptr0, *ptr1; if (!OBJ_INIT_COPY(obj, orig)) return obj; ptr0 = enumerator_ptr(orig); if (ptr0->fib) { /* Fibers cannot be copied */ rb_raise(rb_eTypeError, "can't copy execution context"); } TypedData_Get_Struct(obj, struct enumerator, &enumerator_data_type, ptr1); if (!ptr1) { rb_raise(rb_eArgError, "unallocated enumerator"); } ptr1->obj = ptr0->obj; ptr1->meth = ptr0->meth; ptr1->args = ptr0->args; ptr1->fib = 0; ptr1->lookahead = Qundef; ptr1->feedvalue = Qundef; ptr1->size = ptr0->size; ptr1->size_fn = ptr0->size_fn; return obj; } /* * For backwards compatibility; use rb_enumeratorize_with_size */ VALUE rb_enumeratorize(VALUE obj, VALUE meth, int argc, const VALUE *argv) { return rb_enumeratorize_with_size(obj, meth, argc, argv, 0); } static VALUE lazy_to_enum_i(VALUE self, VALUE meth, int argc, const VALUE *argv, rb_enumerator_size_func *size_fn); VALUE rb_enumeratorize_with_size(VALUE obj, VALUE meth, int argc, const VALUE *argv, rb_enumerator_size_func *size_fn) { /* Similar effect as calling obj.to_enum, i.e. dispatching to either Kernel#to_enum vs Lazy#to_enum */ if (RTEST(rb_obj_is_kind_of(obj, rb_cLazy))) return lazy_to_enum_i(obj, meth, argc, argv, size_fn); else return enumerator_init(enumerator_allocate(rb_cEnumerator), obj, meth, argc, argv, size_fn, Qnil); } static VALUE enumerator_block_call(VALUE obj, rb_block_call_func *func, VALUE arg) { int argc = 0; const VALUE *argv = 0; const struct enumerator *e = enumerator_ptr(obj); ID meth = e->meth; if (e->args) { argc = RARRAY_LENINT(e->args); argv = RARRAY_CONST_PTR(e->args); } return rb_block_call(e->obj, meth, argc, argv, func, arg); } /* * call-seq: * enum.each { |elm| block } -> obj * enum.each -> enum * enum.each(*appending_args) { |elm| block } -> obj * enum.each(*appending_args) -> an_enumerator * * Iterates over the block according to how this Enumerator was constructed. * If no block and no arguments are given, returns self. * * === Examples * * "Hello, world!".scan(/\w+/) #=> ["Hello", "world"] * "Hello, world!".to_enum(:scan, /\w+/).to_a #=> ["Hello", "world"] * "Hello, world!".to_enum(:scan).each(/\w+/).to_a #=> ["Hello", "world"] * * obj = Object.new * * def obj.each_arg(a, b=:b, *rest) * yield a * yield b * yield rest * :method_returned * end * * enum = obj.to_enum :each_arg, :a, :x * * enum.each.to_a #=> [:a, :x, []] * enum.each.equal?(enum) #=> true * enum.each { |elm| elm } #=> :method_returned * * enum.each(:y, :z).to_a #=> [:a, :x, [:y, :z]] * enum.each(:y, :z).equal?(enum) #=> false * enum.each(:y, :z) { |elm| elm } #=> :method_returned * */ static VALUE enumerator_each(int argc, VALUE *argv, VALUE obj) { if (argc > 0) { struct enumerator *e = enumerator_ptr(obj = rb_obj_dup(obj)); VALUE args = e->args; if (args) { #if SIZEOF_INT < SIZEOF_LONG /* check int range overflow */ rb_long2int(RARRAY_LEN(args) + argc); #endif args = rb_ary_dup(args); rb_ary_cat(args, argv, argc); } else { args = rb_ary_new4(argc, argv); } e->args = args; } if (!rb_block_given_p()) return obj; return enumerator_block_call(obj, 0, obj); } static VALUE enumerator_with_index_i(RB_BLOCK_CALL_FUNC_ARGLIST(val, m)) { struct MEMO *memo = (struct MEMO *)m; VALUE idx = memo->v1; MEMO_V1_SET(memo, rb_int_succ(idx)); if (argc <= 1) return rb_yield_values(2, val, idx); return rb_yield_values(2, rb_ary_new4(argc, argv), idx); } static VALUE enumerator_size(VALUE obj); static VALUE enumerator_enum_size(VALUE obj, VALUE args, VALUE eobj) { return enumerator_size(obj); } /* * call-seq: * e.with_index(offset = 0) {|(*args), idx| ... } * e.with_index(offset = 0) * * Iterates the given block for each element with an index, which * starts from +offset+. If no block is given, returns a new Enumerator * that includes the index, starting from +offset+ * * +offset+:: the starting index to use * */ static VALUE enumerator_with_index(int argc, VALUE *argv, VALUE obj) { VALUE memo; rb_scan_args(argc, argv, "01", &memo); RETURN_SIZED_ENUMERATOR(obj, argc, argv, enumerator_enum_size); if (NIL_P(memo)) memo = INT2FIX(0); else memo = rb_to_int(memo); return enumerator_block_call(obj, enumerator_with_index_i, (VALUE)MEMO_NEW(memo, 0, 0)); } /* * call-seq: * e.each_with_index {|(*args), idx| ... } * e.each_with_index * * Same as Enumerator#with_index(0), i.e. there is no starting offset. * * If no block is given, a new Enumerator is returned that includes the index. * */ static VALUE enumerator_each_with_index(VALUE obj) { return enumerator_with_index(0, NULL, obj); } static VALUE enumerator_with_object_i(RB_BLOCK_CALL_FUNC_ARGLIST(val, memo)) { if (argc <= 1) return rb_yield_values(2, val, memo); return rb_yield_values(2, rb_ary_new4(argc, argv), memo); } /* * call-seq: * e.each_with_object(obj) {|(*args), obj| ... } * e.each_with_object(obj) * e.with_object(obj) {|(*args), obj| ... } * e.with_object(obj) * * Iterates the given block for each element with an arbitrary object, +obj+, * and returns +obj+ * * If no block is given, returns a new Enumerator. * * === Example * * to_three = Enumerator.new do |y| * 3.times do |x| * y << x * end * end * * to_three_with_string = to_three.with_object("foo") * to_three_with_string.each do |x,string| * puts "#{string}: #{x}" * end * * # => foo:0 * # => foo:1 * # => foo:2 */ static VALUE enumerator_with_object(VALUE obj, VALUE memo) { RETURN_SIZED_ENUMERATOR(obj, 1, &memo, enumerator_enum_size); enumerator_block_call(obj, enumerator_with_object_i, memo); return memo; } static VALUE next_ii(RB_BLOCK_CALL_FUNC_ARGLIST(i, obj)) { struct enumerator *e = enumerator_ptr(obj); VALUE feedvalue = Qnil; VALUE args = rb_ary_new4(argc, argv); rb_fiber_yield(1, &args); if (e->feedvalue != Qundef) { feedvalue = e->feedvalue; e->feedvalue = Qundef; } return feedvalue; } static VALUE next_i(VALUE curr, VALUE obj) { struct enumerator *e = enumerator_ptr(obj); VALUE nil = Qnil; VALUE result; result = rb_block_call(obj, id_each, 0, 0, next_ii, obj); e->stop_exc = rb_exc_new2(rb_eStopIteration, "iteration reached an end"); rb_ivar_set(e->stop_exc, id_result, result); return rb_fiber_yield(1, &nil); } static void next_init(VALUE obj, struct enumerator *e) { VALUE curr = rb_fiber_current(); e->dst = curr; e->fib = rb_fiber_new(next_i, obj); e->lookahead = Qundef; } static VALUE get_next_values(VALUE obj, struct enumerator *e) { VALUE curr, vs; if (e->stop_exc) rb_exc_raise(e->stop_exc); curr = rb_fiber_current(); if (!e->fib || !rb_fiber_alive_p(e->fib)) { next_init(obj, e); } vs = rb_fiber_resume(e->fib, 1, &curr); if (e->stop_exc) { e->fib = 0; e->dst = Qnil; e->lookahead = Qundef; e->feedvalue = Qundef; rb_exc_raise(e->stop_exc); } return vs; } /* * call-seq: * e.next_values -> array * * Returns the next object as an array in the enumerator, and move the * internal position forward. When the position reached at the end, * StopIteration is raised. * * This method can be used to distinguish yield and yield * nil. * * === Example * * o = Object.new * def o.each * yield * yield 1 * yield 1, 2 * yield nil * yield [1, 2] * end * e = o.to_enum * p e.next_values * p e.next_values * p e.next_values * p e.next_values * p e.next_values * e = o.to_enum * p e.next * p e.next * p e.next * p e.next * p e.next * * ## yield args next_values next * # yield [] nil * # yield 1 [1] 1 * # yield 1, 2 [1, 2] [1, 2] * # yield nil [nil] nil * # yield [1, 2] [[1, 2]] [1, 2] * * Note that +next_values+ does not affect other non-external enumeration * methods unless underlying iteration method itself has side-effect, e.g. * IO#each_line. * */ static VALUE enumerator_next_values(VALUE obj) { struct enumerator *e = enumerator_ptr(obj); VALUE vs; if (e->lookahead != Qundef) { vs = e->lookahead; e->lookahead = Qundef; return vs; } return get_next_values(obj, e); } static VALUE ary2sv(VALUE args, int dup) { if (!RB_TYPE_P(args, T_ARRAY)) return args; switch (RARRAY_LEN(args)) { case 0: return Qnil; case 1: return RARRAY_AREF(args, 0); default: if (dup) return rb_ary_dup(args); return args; } } /* * call-seq: * e.next -> object * * Returns the next object in the enumerator, and move the internal position * forward. When the position reached at the end, StopIteration is raised. * * === Example * * a = [1,2,3] * e = a.to_enum * p e.next #=> 1 * p e.next #=> 2 * p e.next #=> 3 * p e.next #raises StopIteration * * Note that enumeration sequence by +next+ does not affect other non-external * enumeration methods, unless the underlying iteration methods itself has * side-effect, e.g. IO#each_line. * */ static VALUE enumerator_next(VALUE obj) { VALUE vs = enumerator_next_values(obj); return ary2sv(vs, 0); } static VALUE enumerator_peek_values(VALUE obj) { struct enumerator *e = enumerator_ptr(obj); if (e->lookahead == Qundef) { e->lookahead = get_next_values(obj, e); } return e->lookahead; } /* * call-seq: * e.peek_values -> array * * Returns the next object as an array, similar to Enumerator#next_values, but * doesn't move the internal position forward. If the position is already at * the end, StopIteration is raised. * * === Example * * o = Object.new * def o.each * yield * yield 1 * yield 1, 2 * end * e = o.to_enum * p e.peek_values #=> [] * e.next * p e.peek_values #=> [1] * p e.peek_values #=> [1] * e.next * p e.peek_values #=> [1, 2] * e.next * p e.peek_values # raises StopIteration * */ static VALUE enumerator_peek_values_m(VALUE obj) { return rb_ary_dup(enumerator_peek_values(obj)); } /* * call-seq: * e.peek -> object * * Returns the next object in the enumerator, but doesn't move the internal * position forward. If the position is already at the end, StopIteration * is raised. * * === Example * * a = [1,2,3] * e = a.to_enum * p e.next #=> 1 * p e.peek #=> 2 * p e.peek #=> 2 * p e.peek #=> 2 * p e.next #=> 2 * p e.next #=> 3 * p e.peek #raises StopIteration * */ static VALUE enumerator_peek(VALUE obj) { VALUE vs = enumerator_peek_values(obj); return ary2sv(vs, 1); } /* * call-seq: * e.feed obj -> nil * * Sets the value to be returned by the next yield inside +e+. * * If the value is not set, the yield returns nil. * * This value is cleared after being yielded. * * # Array#map passes the array's elements to "yield" and collects the * # results of "yield" as an array. * # Following example shows that "next" returns the passed elements and * # values passed to "feed" are collected as an array which can be * # obtained by StopIteration#result. * e = [1,2,3].map * p e.next #=> 1 * e.feed "a" * p e.next #=> 2 * e.feed "b" * p e.next #=> 3 * e.feed "c" * begin * e.next * rescue StopIteration * p $!.result #=> ["a", "b", "c"] * end * * o = Object.new * def o.each * x = yield # (2) blocks * p x # (5) => "foo" * x = yield # (6) blocks * p x # (8) => nil * x = yield # (9) blocks * p x # not reached w/o another e.next * end * * e = o.to_enum * e.next # (1) * e.feed "foo" # (3) * e.next # (4) * e.next # (7) * # (10) */ static VALUE enumerator_feed(VALUE obj, VALUE v) { struct enumerator *e = enumerator_ptr(obj); if (e->feedvalue != Qundef) { rb_raise(rb_eTypeError, "feed value already set"); } e->feedvalue = v; return Qnil; } /* * call-seq: * e.rewind -> e * * Rewinds the enumeration sequence to the beginning. * * If the enclosed object responds to a "rewind" method, it is called. */ static VALUE enumerator_rewind(VALUE obj) { struct enumerator *e = enumerator_ptr(obj); rb_check_funcall(e->obj, id_rewind, 0, 0); e->fib = 0; e->dst = Qnil; e->lookahead = Qundef; e->feedvalue = Qundef; e->stop_exc = Qfalse; return obj; } static struct generator *generator_ptr(VALUE obj); static VALUE append_method(VALUE obj, VALUE str, ID default_method, VALUE default_args); static VALUE inspect_enumerator(VALUE obj, VALUE dummy, int recur) { struct enumerator *e; VALUE eobj, str, cname; TypedData_Get_Struct(obj, struct enumerator, &enumerator_data_type, e); cname = rb_obj_class(obj); if (!e || e->obj == Qundef) { return rb_sprintf("#<%"PRIsVALUE": uninitialized>", rb_class_path(cname)); } if (recur) { str = rb_sprintf("#<%"PRIsVALUE": ...>", rb_class_path(cname)); OBJ_TAINT(str); return str; } if (e->procs) { long i; eobj = generator_ptr(e->obj)->obj; /* In case procs chained enumerator traversing all proc entries manually */ if (rb_obj_class(eobj) == cname) { str = rb_inspect(eobj); } else { str = rb_sprintf("#<%"PRIsVALUE": %+"PRIsVALUE">", rb_class_path(cname), eobj); } for (i = 0; i < RARRAY_LEN(e->procs); i++) { str = rb_sprintf("#<%"PRIsVALUE": %"PRIsVALUE, cname, str); append_method(RARRAY_AREF(e->procs, i), str, e->meth, e->args); rb_str_buf_cat2(str, ">"); } return str; } eobj = rb_attr_get(obj, id_receiver); if (NIL_P(eobj)) { eobj = e->obj; } /* (1..100).each_cons(2) => "#" */ str = rb_sprintf("#<%"PRIsVALUE": %+"PRIsVALUE, rb_class_path(cname), eobj); append_method(obj, str, e->meth, e->args); rb_str_buf_cat2(str, ">"); return str; } static VALUE append_method(VALUE obj, VALUE str, ID default_method, VALUE default_args) { VALUE method, eargs; method = rb_attr_get(obj, id_method); if (method != Qfalse) { if (!NIL_P(method)) { Check_Type(method, T_SYMBOL); method = rb_sym2str(method); } else { method = rb_id2str(default_method); } rb_str_buf_cat2(str, ":"); rb_str_buf_append(str, method); } eargs = rb_attr_get(obj, id_arguments); if (NIL_P(eargs)) { eargs = default_args; } if (eargs != Qfalse) { long argc = RARRAY_LEN(eargs); const VALUE *argv = RARRAY_CONST_PTR(eargs); /* WB: no new reference */ if (argc > 0) { rb_str_buf_cat2(str, "("); while (argc--) { VALUE arg = *argv++; rb_str_append(str, rb_inspect(arg)); rb_str_buf_cat2(str, argc > 0 ? ", " : ")"); OBJ_INFECT(str, arg); } } } return str; } /* * call-seq: * e.inspect -> string * * Creates a printable version of e. */ static VALUE enumerator_inspect(VALUE obj) { return rb_exec_recursive(inspect_enumerator, obj, 0); } /* * call-seq: * e.size -> int, Float::INFINITY or nil * * Returns the size of the enumerator, or +nil+ if it can't be calculated lazily. * * (1..100).to_a.permutation(4).size # => 94109400 * loop.size # => Float::INFINITY * (1..100).drop_while.size # => nil */ static VALUE enumerator_size(VALUE obj) { struct enumerator *e = enumerator_ptr(obj); int argc = 0; const VALUE *argv = NULL; VALUE size; if (e->procs) { struct generator *g = generator_ptr(e->obj); VALUE receiver = rb_check_funcall(g->obj, id_size, 0, 0); long i = 0; for (i = 0; i < RARRAY_LEN(e->procs); i++) { VALUE proc = RARRAY_AREF(e->procs, i); struct proc_entry *entry = proc_entry_ptr(proc); lazyenum_size_func *size = entry->fn->size; if (!size) { return Qnil; } receiver = (*size)(proc, receiver); } return receiver; } if (e->size_fn) { return (*e->size_fn)(e->obj, e->args, obj); } if (e->args) { argc = (int)RARRAY_LEN(e->args); argv = RARRAY_CONST_PTR(e->args); } size = rb_check_funcall(e->size, id_call, argc, argv); if (size != Qundef) return size; return e->size; } /* * Yielder */ static void yielder_mark(void *p) { struct yielder *ptr = p; rb_gc_mark(ptr->proc); } #define yielder_free RUBY_TYPED_DEFAULT_FREE static size_t yielder_memsize(const void *p) { return sizeof(struct yielder); } static const rb_data_type_t yielder_data_type = { "yielder", { yielder_mark, yielder_free, yielder_memsize, }, 0, 0, RUBY_TYPED_FREE_IMMEDIATELY }; static struct yielder * yielder_ptr(VALUE obj) { struct yielder *ptr; TypedData_Get_Struct(obj, struct yielder, &yielder_data_type, ptr); if (!ptr || ptr->proc == Qundef) { rb_raise(rb_eArgError, "uninitialized yielder"); } return ptr; } /* :nodoc: */ static VALUE yielder_allocate(VALUE klass) { struct yielder *ptr; VALUE obj; obj = TypedData_Make_Struct(klass, struct yielder, &yielder_data_type, ptr); ptr->proc = Qundef; return obj; } static VALUE yielder_init(VALUE obj, VALUE proc) { struct yielder *ptr; TypedData_Get_Struct(obj, struct yielder, &yielder_data_type, ptr); if (!ptr) { rb_raise(rb_eArgError, "unallocated yielder"); } ptr->proc = proc; return obj; } /* :nodoc: */ static VALUE yielder_initialize(VALUE obj) { rb_need_block(); return yielder_init(obj, rb_block_proc()); } /* :nodoc: */ static VALUE yielder_yield(VALUE obj, VALUE args) { struct yielder *ptr = yielder_ptr(obj); return rb_proc_call(ptr->proc, args); } /* :nodoc: */ static VALUE yielder_yield_push(VALUE obj, VALUE args) { yielder_yield(obj, args); return obj; } static VALUE yielder_yield_i(RB_BLOCK_CALL_FUNC_ARGLIST(obj, memo)) { return rb_yield_values2(argc, argv); } static VALUE yielder_new(void) { return yielder_init(yielder_allocate(rb_cYielder), rb_proc_new(yielder_yield_i, 0)); } /* * Generator */ static void generator_mark(void *p) { struct generator *ptr = p; rb_gc_mark(ptr->proc); rb_gc_mark(ptr->obj); } #define generator_free RUBY_TYPED_DEFAULT_FREE static size_t generator_memsize(const void *p) { return sizeof(struct generator); } static const rb_data_type_t generator_data_type = { "generator", { generator_mark, generator_free, generator_memsize, }, 0, 0, RUBY_TYPED_FREE_IMMEDIATELY }; static struct generator * generator_ptr(VALUE obj) { struct generator *ptr; TypedData_Get_Struct(obj, struct generator, &generator_data_type, ptr); if (!ptr || ptr->proc == Qundef) { rb_raise(rb_eArgError, "uninitialized generator"); } return ptr; } /* :nodoc: */ static VALUE generator_allocate(VALUE klass) { struct generator *ptr; VALUE obj; obj = TypedData_Make_Struct(klass, struct generator, &generator_data_type, ptr); ptr->proc = Qundef; return obj; } static VALUE generator_init(VALUE obj, VALUE proc) { struct generator *ptr; rb_check_frozen(obj); TypedData_Get_Struct(obj, struct generator, &generator_data_type, ptr); if (!ptr) { rb_raise(rb_eArgError, "unallocated generator"); } ptr->proc = proc; return obj; } /* :nodoc: */ static VALUE generator_initialize(int argc, VALUE *argv, VALUE obj) { VALUE proc; if (argc == 0) { rb_need_block(); proc = rb_block_proc(); } else { rb_scan_args(argc, argv, "1", &proc); if (!rb_obj_is_proc(proc)) rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE" (expected Proc)", rb_obj_class(proc)); if (rb_block_given_p()) { rb_warn("given block not used"); } } return generator_init(obj, proc); } /* :nodoc: */ static VALUE generator_init_copy(VALUE obj, VALUE orig) { struct generator *ptr0, *ptr1; if (!OBJ_INIT_COPY(obj, orig)) return obj; ptr0 = generator_ptr(orig); TypedData_Get_Struct(obj, struct generator, &generator_data_type, ptr1); if (!ptr1) { rb_raise(rb_eArgError, "unallocated generator"); } ptr1->proc = ptr0->proc; return obj; } /* :nodoc: */ static VALUE generator_each(int argc, VALUE *argv, VALUE obj) { struct generator *ptr = generator_ptr(obj); VALUE args = rb_ary_new2(argc + 1); rb_ary_push(args, yielder_new()); if (argc > 0) { rb_ary_cat(args, argv, argc); } return rb_proc_call(ptr->proc, args); } /* Lazy Enumerator methods */ static VALUE enum_size(VALUE self) { VALUE r = rb_check_funcall(self, id_size, 0, 0); return (r == Qundef) ? Qnil : r; } static VALUE lazyenum_size(VALUE self, VALUE args, VALUE eobj) { return enum_size(self); } static VALUE lazy_size(VALUE self) { return enum_size(rb_ivar_get(self, id_receiver)); } static VALUE lazy_receiver_size(VALUE generator, VALUE args, VALUE lazy) { return lazy_size(lazy); } static VALUE lazy_init_iterator(RB_BLOCK_CALL_FUNC_ARGLIST(val, m)) { VALUE result; if (argc == 1) { VALUE args[2]; args[0] = m; args[1] = val; result = rb_yield_values2(2, args); } else { VALUE args; int len = rb_long2int((long)argc + 1); VALUE *nargv = ALLOCV_N(VALUE, args, len); nargv[0] = m; if (argc > 0) { MEMCPY(nargv + 1, argv, VALUE, argc); } result = rb_yield_values2(len, nargv); ALLOCV_END(args); } if (result == Qundef) rb_iter_break(); return Qnil; } static VALUE lazy_init_block_i(RB_BLOCK_CALL_FUNC_ARGLIST(val, m)) { rb_block_call(m, id_each, argc-1, argv+1, lazy_init_iterator, val); return Qnil; } #define memo_value v2 #define memo_flags u3.state #define LAZY_MEMO_BREAK 1 #define LAZY_MEMO_PACKED 2 #define LAZY_MEMO_BREAK_P(memo) ((memo)->memo_flags & LAZY_MEMO_BREAK) #define LAZY_MEMO_PACKED_P(memo) ((memo)->memo_flags & LAZY_MEMO_PACKED) #define LAZY_MEMO_SET_BREAK(memo) ((memo)->memo_flags |= LAZY_MEMO_BREAK) #define LAZY_MEMO_SET_VALUE(memo, value) MEMO_V2_SET(memo, value) static VALUE lazy_init_yielder(VALUE val, VALUE m, int argc, VALUE *argv) { VALUE yielder = RARRAY_AREF(m, 0); VALUE procs_array = RARRAY_AREF(m, 1); VALUE memos = rb_attr_get(yielder, id_memo); long i = 0; struct MEMO *result; int cont = 1; result = MEMO_NEW(Qnil, rb_enum_values_pack(argc, argv), argc > 1 ? LAZY_MEMO_PACKED : 0); for (i = 0; i < RARRAY_LEN(procs_array); i++) { VALUE proc = RARRAY_AREF(procs_array, i); struct proc_entry *entry = proc_entry_ptr(proc); if (!(*entry->fn->proc)(proc, result, memos, i)) { cont = 0; break; } } if (cont) { rb_funcall2(yielder, id_yield, 1, &(result->memo_value)); } if (LAZY_MEMO_BREAK_P(result)) { rb_iter_break(); } return result->memo_value; } static VALUE lazy_init_block(VALUE val, VALUE m, int argc, VALUE *argv) { VALUE procs = RARRAY_AREF(m, 1); rb_ivar_set(val, id_memo, rb_ary_new2(RARRAY_LEN(procs))); rb_block_call(RARRAY_AREF(m, 0), id_each, 0, 0, lazy_init_yielder, rb_ary_new3(2, val, procs)); return Qnil; } static VALUE lazy_generator_init(VALUE enumerator, VALUE procs) { VALUE generator; VALUE obj; struct generator *gen_ptr; struct enumerator *e = enumerator_ptr(enumerator); if (RARRAY_LEN(procs) > 0) { struct generator *old_gen_ptr = generator_ptr(e->obj); obj = old_gen_ptr->obj; } else { obj = enumerator; } generator = generator_allocate(rb_cGenerator); rb_block_call(generator, id_initialize, 0, 0, lazy_init_block, rb_ary_new3(2, obj, procs)); gen_ptr = generator_ptr(generator); gen_ptr->obj = obj; return generator; } /* * call-seq: * Lazy.new(obj, size=nil) { |yielder, *values| ... } * * Creates a new Lazy enumerator. When the enumerator is actually enumerated * (e.g. by calling #force), +obj+ will be enumerated and each value passed * to the given block. The block can yield values back using +yielder+. * For example, to create a method +filter_map+ in both lazy and * non-lazy fashions: * * module Enumerable * def filter_map(&block) * map(&block).compact * end * end * * class Enumerator::Lazy * def filter_map * Lazy.new(self) do |yielder, *values| * result = yield *values * yielder << result if result * end * end * end * * (1..Float::INFINITY).lazy.filter_map{|i| i*i if i.even?}.first(5) * # => [4, 16, 36, 64, 100] */ static VALUE lazy_initialize(int argc, VALUE *argv, VALUE self) { VALUE obj, size = Qnil; VALUE generator; rb_check_arity(argc, 1, 2); if (!rb_block_given_p()) { rb_raise(rb_eArgError, "tried to call lazy new without a block"); } obj = argv[0]; if (argc > 1) { size = argv[1]; } generator = generator_allocate(rb_cGenerator); rb_block_call(generator, id_initialize, 0, 0, lazy_init_block_i, obj); enumerator_init(self, generator, sym_each, 0, 0, 0, size); rb_ivar_set(self, id_receiver, obj); return self; } static void lazy_set_args(VALUE lazy, VALUE args) { ID id = rb_frame_this_func(); rb_ivar_set(lazy, id_method, ID2SYM(id)); if (NIL_P(args)) { /* Qfalse indicates that the arguments are empty */ rb_ivar_set(lazy, id_arguments, Qfalse); } else { rb_ivar_set(lazy, id_arguments, args); } } static VALUE lazy_set_method(VALUE lazy, VALUE args, rb_enumerator_size_func *size_fn) { struct enumerator *e = enumerator_ptr(lazy); lazy_set_args(lazy, args); e->size_fn = size_fn; return lazy; } static VALUE lazy_add_method(VALUE obj, int argc, VALUE *argv, VALUE args, VALUE memo, const lazyenum_funcs *fn) { struct enumerator *new_e; VALUE new_obj; VALUE new_generator; VALUE new_procs; struct enumerator *e = enumerator_ptr(obj); struct proc_entry *entry; VALUE entry_obj = TypedData_Make_Struct(rb_cObject, struct proc_entry, &proc_entry_data_type, entry); if (rb_block_given_p()) { entry->proc = rb_block_proc(); } entry->fn = fn; entry->memo = args; lazy_set_args(entry_obj, memo); new_procs = RTEST(e->procs) ? rb_ary_dup(e->procs) : rb_ary_new(); new_generator = lazy_generator_init(obj, new_procs); rb_ary_push(new_procs, entry_obj); new_obj = enumerator_init_copy(enumerator_allocate(rb_cLazy), obj); new_e = DATA_PTR(new_obj); new_e->obj = new_generator; new_e->procs = new_procs; if (argc > 0) { new_e->meth = rb_to_id(*argv++); --argc; } else { new_e->meth = id_each; } new_e->args = rb_ary_new4(argc, argv); return new_obj; } /* * call-seq: * e.lazy -> lazy_enumerator * * Returns a lazy enumerator, whose methods map/collect, * flat_map/collect_concat, select/find_all, reject, grep, grep_v, zip, take, * take_while, drop, and drop_while enumerate values only on an * as-needed basis. However, if a block is given to zip, values * are enumerated immediately. * * === Example * * The following program finds pythagorean triples: * * def pythagorean_triples * (1..Float::INFINITY).lazy.flat_map {|z| * (1..z).flat_map {|x| * (x..z).select {|y| * x**2 + y**2 == z**2 * }.map {|y| * [x, y, z] * } * } * } * end * # show first ten pythagorean triples * p pythagorean_triples.take(10).force # take is lazy, so force is needed * p pythagorean_triples.first(10) # first is eager * # show pythagorean triples less than 100 * p pythagorean_triples.take_while { |*, z| z < 100 }.force */ static VALUE enumerable_lazy(VALUE obj) { VALUE result = lazy_to_enum_i(obj, sym_each, 0, 0, lazyenum_size); /* Qfalse indicates that the Enumerator::Lazy has no method name */ rb_ivar_set(result, id_method, Qfalse); return result; } static VALUE lazy_to_enum_i(VALUE obj, VALUE meth, int argc, const VALUE *argv, rb_enumerator_size_func *size_fn) { return enumerator_init(enumerator_allocate(rb_cLazy), obj, meth, argc, argv, size_fn, Qnil); } /* * call-seq: * lzy.to_enum(method = :each, *args) -> lazy_enum * lzy.enum_for(method = :each, *args) -> lazy_enum * lzy.to_enum(method = :each, *args) {|*args| block} -> lazy_enum * lzy.enum_for(method = :each, *args){|*args| block} -> lazy_enum * * Similar to Kernel#to_enum, except it returns a lazy enumerator. * This makes it easy to define Enumerable methods that will * naturally remain lazy if called from a lazy enumerator. * * For example, continuing from the example in Kernel#to_enum: * * # See Kernel#to_enum for the definition of repeat * r = 1..Float::INFINITY * r.repeat(2).first(5) # => [1, 1, 2, 2, 3] * r.repeat(2).class # => Enumerator * r.repeat(2).map{|n| n ** 2}.first(5) # => endless loop! * # works naturally on lazy enumerator: * r.lazy.repeat(2).class # => Enumerator::Lazy * r.lazy.repeat(2).map{|n| n ** 2}.first(5) # => [1, 1, 4, 4, 9] */ static VALUE lazy_to_enum(int argc, VALUE *argv, VALUE self) { VALUE lazy, meth = sym_each; if (argc > 0) { --argc; meth = *argv++; } lazy = lazy_to_enum_i(self, meth, argc, argv, 0); if (rb_block_given_p()) { enumerator_ptr(lazy)->size = rb_block_proc(); } return lazy; } static VALUE lazyenum_yield(VALUE proc_entry, struct MEMO *result) { struct proc_entry *entry = proc_entry_ptr(proc_entry); return rb_proc_call_with_block(entry->proc, 1, &result->memo_value, Qnil); } static VALUE lazyenum_yield_values(VALUE proc_entry, struct MEMO *result) { struct proc_entry *entry = proc_entry_ptr(proc_entry); int argc = 1; const VALUE *argv = &result->memo_value; if (LAZY_MEMO_PACKED_P(result)) { const VALUE args = *argv; argc = RARRAY_LENINT(args); argv = RARRAY_CONST_PTR(args); } return rb_proc_call_with_block(entry->proc, argc, argv, Qnil); } static struct MEMO * lazy_map_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo_index) { VALUE value = lazyenum_yield_values(proc_entry, result); LAZY_MEMO_SET_VALUE(result, value); return result; } static VALUE lazy_map_size(VALUE entry, VALUE receiver) { return receiver; } static const lazyenum_funcs lazy_map_funcs = { lazy_map_proc, lazy_map_size, }; static VALUE lazy_map(VALUE obj) { if (!rb_block_given_p()) { rb_raise(rb_eArgError, "tried to call lazy map without a block"); } return lazy_add_method(obj, 0, 0, Qnil, Qnil, &lazy_map_funcs); } static VALUE lazy_flat_map_i(RB_BLOCK_CALL_FUNC_ARGLIST(i, yielder)) { return rb_funcallv(yielder, id_yield, argc, argv); } static VALUE lazy_flat_map_each(VALUE obj, VALUE yielder) { rb_block_call(obj, id_each, 0, 0, lazy_flat_map_i, yielder); return Qnil; } static VALUE lazy_flat_map_to_ary(VALUE obj, VALUE yielder) { VALUE ary = rb_check_array_type(obj); if (NIL_P(ary)) { rb_funcall(yielder, id_yield, 1, obj); } else { long i; for (i = 0; i < RARRAY_LEN(ary); i++) { rb_funcall(yielder, id_yield, 1, RARRAY_AREF(ary, i)); } } return Qnil; } static VALUE lazy_flat_map_proc(RB_BLOCK_CALL_FUNC_ARGLIST(val, m)) { VALUE result = rb_yield_values2(argc - 1, &argv[1]); if (RB_TYPE_P(result, T_ARRAY)) { long i; for (i = 0; i < RARRAY_LEN(result); i++) { rb_funcall(argv[0], id_yield, 1, RARRAY_AREF(result, i)); } } else { if (rb_respond_to(result, id_force) && rb_respond_to(result, id_each)) { lazy_flat_map_each(result, argv[0]); } else { lazy_flat_map_to_ary(result, argv[0]); } } return Qnil; } /* * call-seq: * lazy.collect_concat { |obj| block } -> a_lazy_enumerator * lazy.flat_map { |obj| block } -> a_lazy_enumerator * * Returns a new lazy enumerator with the concatenated results of running * block once for every element in lazy. * * ["foo", "bar"].lazy.flat_map {|i| i.each_char.lazy}.force * #=> ["f", "o", "o", "b", "a", "r"] * * A value x returned by block is decomposed if either of * the following conditions is true: * * a) x responds to both each and force, which means that * x is a lazy enumerator. * b) x is an array or responds to to_ary. * * Otherwise, x is contained as-is in the return value. * * [{a:1}, {b:2}].lazy.flat_map {|i| i}.force * #=> [{:a=>1}, {:b=>2}] */ static VALUE lazy_flat_map(VALUE obj) { if (!rb_block_given_p()) { rb_raise(rb_eArgError, "tried to call lazy flat_map without a block"); } return lazy_set_method(rb_block_call(rb_cLazy, id_new, 1, &obj, lazy_flat_map_proc, 0), Qnil, 0); } static struct MEMO * lazy_select_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo_index) { VALUE chain = lazyenum_yield(proc_entry, result); if (!RTEST(chain)) return 0; return result; } static const lazyenum_funcs lazy_select_funcs = { lazy_select_proc, 0, }; static VALUE lazy_select(VALUE obj) { if (!rb_block_given_p()) { rb_raise(rb_eArgError, "tried to call lazy select without a block"); } return lazy_add_method(obj, 0, 0, Qnil, Qnil, &lazy_select_funcs); } static struct MEMO * lazy_reject_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo_index) { VALUE chain = lazyenum_yield(proc_entry, result); if (RTEST(chain)) return 0; return result; } static const lazyenum_funcs lazy_reject_funcs = { lazy_reject_proc, 0, }; static VALUE lazy_reject(VALUE obj) { if (!rb_block_given_p()) { rb_raise(rb_eArgError, "tried to call lazy reject without a block"); } return lazy_add_method(obj, 0, 0, Qnil, Qnil, &lazy_reject_funcs); } static struct MEMO * lazy_grep_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo_index) { struct proc_entry *entry = proc_entry_ptr(proc_entry); VALUE chain = rb_funcall(entry->memo, id_eqq, 1, result->memo_value); if (!RTEST(chain)) return 0; return result; } static struct MEMO * lazy_grep_iter_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo_index) { struct proc_entry *entry = proc_entry_ptr(proc_entry); VALUE value, chain = rb_funcall(entry->memo, id_eqq, 1, result->memo_value); if (!RTEST(chain)) return 0; value = rb_proc_call_with_block(entry->proc, 1, &(result->memo_value), Qnil); LAZY_MEMO_SET_VALUE(result, value); return result; } static const lazyenum_funcs lazy_grep_iter_funcs = { lazy_grep_iter_proc, 0, }; static const lazyenum_funcs lazy_grep_funcs = { lazy_grep_proc, 0, }; static VALUE lazy_grep(VALUE obj, VALUE pattern) { const lazyenum_funcs *const funcs = rb_block_given_p() ? &lazy_grep_iter_funcs : &lazy_grep_funcs; return lazy_add_method(obj, 0, 0, pattern, rb_ary_new3(1, pattern), funcs); } static VALUE lazy_grep_v_func(RB_BLOCK_CALL_FUNC_ARGLIST(val, m)) { VALUE i = rb_enum_values_pack(argc - 1, argv + 1); VALUE result = rb_funcall(m, id_eqq, 1, i); if (!RTEST(result)) { rb_funcall(argv[0], id_yield, 1, i); } return Qnil; } static VALUE lazy_grep_v_iter(RB_BLOCK_CALL_FUNC_ARGLIST(val, m)) { VALUE i = rb_enum_values_pack(argc - 1, argv + 1); VALUE result = rb_funcall(m, id_eqq, 1, i); if (!RTEST(result)) { rb_funcall(argv[0], id_yield, 1, rb_yield(i)); } return Qnil; } static VALUE lazy_grep_v(VALUE obj, VALUE pattern) { return lazy_set_method(rb_block_call(rb_cLazy, id_new, 1, &obj, rb_block_given_p() ? lazy_grep_v_iter : lazy_grep_v_func, pattern), rb_ary_new3(1, pattern), 0); } static VALUE call_next(VALUE obj) { return rb_funcall(obj, id_next, 0); } static VALUE next_stopped(VALUE obj) { return Qnil; } static VALUE lazy_zip_arrays_func(RB_BLOCK_CALL_FUNC_ARGLIST(val, arrays)) { VALUE yielder, ary, memo; long i, count; yielder = argv[0]; memo = rb_attr_get(yielder, id_memo); count = NIL_P(memo) ? 0 : NUM2LONG(memo); ary = rb_ary_new2(RARRAY_LEN(arrays) + 1); rb_ary_push(ary, argv[1]); for (i = 0; i < RARRAY_LEN(arrays); i++) { rb_ary_push(ary, rb_ary_entry(RARRAY_AREF(arrays, i), count)); } rb_funcall(yielder, id_yield, 1, ary); rb_ivar_set(yielder, id_memo, LONG2NUM(++count)); return Qnil; } static VALUE lazy_zip_func(RB_BLOCK_CALL_FUNC_ARGLIST(val, zip_args)) { VALUE yielder, ary, arg, v; long i; yielder = argv[0]; arg = rb_attr_get(yielder, id_memo); if (NIL_P(arg)) { arg = rb_ary_new2(RARRAY_LEN(zip_args)); for (i = 0; i < RARRAY_LEN(zip_args); i++) { rb_ary_push(arg, rb_funcall(RARRAY_AREF(zip_args, i), id_to_enum, 0)); } rb_ivar_set(yielder, id_memo, arg); } ary = rb_ary_new2(RARRAY_LEN(arg) + 1); v = Qnil; if (--argc > 0) { ++argv; v = argc > 1 ? rb_ary_new_from_values(argc, argv) : *argv; } rb_ary_push(ary, v); for (i = 0; i < RARRAY_LEN(arg); i++) { v = rb_rescue2(call_next, RARRAY_AREF(arg, i), next_stopped, 0, rb_eStopIteration, (VALUE)0); rb_ary_push(ary, v); } rb_funcall(yielder, id_yield, 1, ary); return Qnil; } static VALUE lazy_zip(int argc, VALUE *argv, VALUE obj) { VALUE ary, v; long i; rb_block_call_func *func = lazy_zip_arrays_func; if (rb_block_given_p()) { return rb_call_super(argc, argv); } ary = rb_ary_new2(argc); for (i = 0; i < argc; i++) { v = rb_check_array_type(argv[i]); if (NIL_P(v)) { for (; i < argc; i++) { if (!rb_respond_to(argv[i], id_each)) { rb_raise(rb_eTypeError, "wrong argument type %"PRIsVALUE" (must respond to :each)", rb_obj_class(argv[i])); } } ary = rb_ary_new4(argc, argv); func = lazy_zip_func; break; } rb_ary_push(ary, v); } return lazy_set_method(rb_block_call(rb_cLazy, id_new, 1, &obj, func, ary), ary, lazy_receiver_size); } static struct MEMO * lazy_take_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo_index) { long remain; struct proc_entry *entry = proc_entry_ptr(proc_entry); VALUE memo = rb_ary_entry(memos, memo_index); if (NIL_P(memo)) { memo = entry->memo; } remain = NUM2LONG(memo); if (remain == 0) { LAZY_MEMO_SET_BREAK(result); } else { if (--remain == 0) LAZY_MEMO_SET_BREAK(result); rb_ary_store(memos, memo_index, LONG2NUM(remain)); } return result; } static VALUE lazy_take_size(VALUE entry, VALUE receiver) { long len = NUM2LONG(RARRAY_AREF(rb_ivar_get(entry, id_arguments), 0)); if (NIL_P(receiver) || (FIXNUM_P(receiver) && FIX2LONG(receiver) < len)) return receiver; return LONG2NUM(len); } static const lazyenum_funcs lazy_take_funcs = { lazy_take_proc, lazy_take_size, }; static VALUE lazy_take(VALUE obj, VALUE n) { long len = NUM2LONG(n); int argc = 0; VALUE argv[2]; if (len < 0) { rb_raise(rb_eArgError, "attempt to take negative size"); } if (len == 0) { argv[0] = sym_cycle; argv[1] = INT2NUM(0); argc = 2; } return lazy_add_method(obj, argc, argv, n, rb_ary_new3(1, n), &lazy_take_funcs); } static struct MEMO * lazy_take_while_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo_index) { VALUE take = lazyenum_yield_values(proc_entry, result); if (!RTEST(take)) { LAZY_MEMO_SET_BREAK(result); return 0; } return result; } static const lazyenum_funcs lazy_take_while_funcs = { lazy_take_while_proc, 0, }; static VALUE lazy_take_while(VALUE obj) { if (!rb_block_given_p()) { rb_raise(rb_eArgError, "tried to call lazy take_while without a block"); } return lazy_add_method(obj, 0, 0, Qnil, Qnil, &lazy_take_while_funcs); } static VALUE lazy_drop_size(VALUE proc_entry, VALUE receiver) { long len = NUM2LONG(RARRAY_AREF(rb_ivar_get(proc_entry, id_arguments), 0)); if (NIL_P(receiver)) return receiver; if (FIXNUM_P(receiver)) { len = FIX2LONG(receiver) - len; return LONG2FIX(len < 0 ? 0 : len); } return rb_funcall(receiver, '-', 1, LONG2NUM(len)); } static struct MEMO * lazy_drop_proc(VALUE proc_entry, struct MEMO *result, VALUE memos, long memo_index) { long remain; struct proc_entry *entry = proc_entry_ptr(proc_entry); VALUE memo = rb_ary_entry(memos, memo_index); if (NIL_P(memo)) { memo = entry->memo; } remain = NUM2LONG(memo); if (remain > 0) { --remain; rb_ary_store(memos, memo_index, LONG2NUM(remain)); return 0; } return result; } static const lazyenum_funcs lazy_drop_funcs = { lazy_drop_proc, lazy_drop_size, }; static VALUE lazy_drop(VALUE obj, VALUE n) { long len = NUM2LONG(n); VALUE argv[2]; argv[0] = sym_each; argv[1] = n; if (len < 0) { rb_raise(rb_eArgError, "attempt to drop negative size"); } return lazy_add_method(obj, 2, argv, n, rb_ary_new3(1, n), &lazy_drop_funcs); } static struct MEMO * lazy_drop_while_proc(VALUE proc_entry, struct MEMO* result, VALUE memos, long memo_index) { struct proc_entry *entry = proc_entry_ptr(proc_entry); VALUE memo = rb_ary_entry(memos, memo_index); if (NIL_P(memo)) { memo = entry->memo; } if (!RTEST(memo)) { VALUE drop = lazyenum_yield_values(proc_entry, result); if (RTEST(drop)) return 0; rb_ary_store(memos, memo_index, Qtrue); } return result; } static const lazyenum_funcs lazy_drop_while_funcs = { lazy_drop_while_proc, 0, }; static VALUE lazy_drop_while(VALUE obj) { if (!rb_block_given_p()) { rb_raise(rb_eArgError, "tried to call lazy drop_while without a block"); } return lazy_add_method(obj, 0, 0, Qfalse, Qnil, &lazy_drop_while_funcs); } static VALUE lazy_uniq_i(VALUE i, VALUE hash, int argc, const VALUE *argv, VALUE yielder) { if (rb_hash_add_new_element(hash, i, Qfalse)) return Qnil; return rb_funcallv(yielder, id_yield, argc, argv); } static VALUE lazy_uniq_func(RB_BLOCK_CALL_FUNC_ARGLIST(i, hash)) { VALUE yielder = (--argc, *argv++); i = rb_enum_values_pack(argc, argv); return lazy_uniq_i(i, hash, argc, argv, yielder); } static VALUE lazy_uniq_iter(RB_BLOCK_CALL_FUNC_ARGLIST(i, hash)) { VALUE yielder = (--argc, *argv++); i = rb_yield_values2(argc, argv); return lazy_uniq_i(i, hash, argc, argv, yielder); } static VALUE lazy_uniq(VALUE obj) { rb_block_call_func *const func = rb_block_given_p() ? lazy_uniq_iter : lazy_uniq_func; VALUE hash = rb_obj_hide(rb_hash_new()); return lazy_set_method(rb_block_call(rb_cLazy, id_new, 1, &obj, func, hash), 0, 0); } static VALUE lazy_super(int argc, VALUE *argv, VALUE lazy) { return enumerable_lazy(rb_call_super(argc, argv)); } static VALUE lazy_lazy(VALUE obj) { return obj; } /* * Document-class: StopIteration * * Raised to stop the iteration, in particular by Enumerator#next. It is * rescued by Kernel#loop. * * loop do * puts "Hello" * raise StopIteration * puts "World" * end * puts "Done!" * * produces: * * Hello * Done! */ /* * call-seq: * result -> value * * Returns the return value of the iterator. * * o = Object.new * def o.each * yield 1 * yield 2 * yield 3 * 100 * end * * e = o.to_enum * * puts e.next #=> 1 * puts e.next #=> 2 * puts e.next #=> 3 * * begin * e.next * rescue StopIteration => ex * puts ex.result #=> 100 * end * */ static VALUE stop_result(VALUE self) { return rb_attr_get(self, id_result); } void InitVM_Enumerator(void) { rb_define_method(rb_mKernel, "to_enum", obj_to_enum, -1); rb_define_method(rb_mKernel, "enum_for", obj_to_enum, -1); rb_cEnumerator = rb_define_class("Enumerator", rb_cObject); rb_include_module(rb_cEnumerator, rb_mEnumerable); rb_define_alloc_func(rb_cEnumerator, enumerator_allocate); rb_define_method(rb_cEnumerator, "initialize", enumerator_initialize, -1); rb_define_method(rb_cEnumerator, "initialize_copy", enumerator_init_copy, 1); rb_define_method(rb_cEnumerator, "each", enumerator_each, -1); rb_define_method(rb_cEnumerator, "each_with_index", enumerator_each_with_index, 0); rb_define_method(rb_cEnumerator, "each_with_object", enumerator_with_object, 1); rb_define_method(rb_cEnumerator, "with_index", enumerator_with_index, -1); rb_define_method(rb_cEnumerator, "with_object", enumerator_with_object, 1); rb_define_method(rb_cEnumerator, "next_values", enumerator_next_values, 0); rb_define_method(rb_cEnumerator, "peek_values", enumerator_peek_values_m, 0); rb_define_method(rb_cEnumerator, "next", enumerator_next, 0); rb_define_method(rb_cEnumerator, "peek", enumerator_peek, 0); rb_define_method(rb_cEnumerator, "feed", enumerator_feed, 1); rb_define_method(rb_cEnumerator, "rewind", enumerator_rewind, 0); rb_define_method(rb_cEnumerator, "inspect", enumerator_inspect, 0); rb_define_method(rb_cEnumerator, "size", enumerator_size, 0); /* Lazy */ rb_cLazy = rb_define_class_under(rb_cEnumerator, "Lazy", rb_cEnumerator); rb_define_method(rb_mEnumerable, "lazy", enumerable_lazy, 0); rb_define_method(rb_cLazy, "initialize", lazy_initialize, -1); rb_define_method(rb_cLazy, "to_enum", lazy_to_enum, -1); rb_define_method(rb_cLazy, "enum_for", lazy_to_enum, -1); rb_define_method(rb_cLazy, "map", lazy_map, 0); rb_define_method(rb_cLazy, "collect", lazy_map, 0); rb_define_method(rb_cLazy, "flat_map", lazy_flat_map, 0); rb_define_method(rb_cLazy, "collect_concat", lazy_flat_map, 0); rb_define_method(rb_cLazy, "select", lazy_select, 0); rb_define_method(rb_cLazy, "find_all", lazy_select, 0); rb_define_method(rb_cLazy, "reject", lazy_reject, 0); rb_define_method(rb_cLazy, "grep", lazy_grep, 1); rb_define_method(rb_cLazy, "grep_v", lazy_grep_v, 1); rb_define_method(rb_cLazy, "zip", lazy_zip, -1); rb_define_method(rb_cLazy, "take", lazy_take, 1); rb_define_method(rb_cLazy, "take_while", lazy_take_while, 0); rb_define_method(rb_cLazy, "drop", lazy_drop, 1); rb_define_method(rb_cLazy, "drop_while", lazy_drop_while, 0); rb_define_method(rb_cLazy, "lazy", lazy_lazy, 0); rb_define_method(rb_cLazy, "chunk", lazy_super, -1); rb_define_method(rb_cLazy, "slice_before", lazy_super, -1); rb_define_method(rb_cLazy, "slice_after", lazy_super, -1); rb_define_method(rb_cLazy, "slice_when", lazy_super, -1); rb_define_method(rb_cLazy, "uniq", lazy_uniq, 0); rb_define_alias(rb_cLazy, "force", "to_a"); rb_eStopIteration = rb_define_class("StopIteration", rb_eIndexError); rb_define_method(rb_eStopIteration, "result", stop_result, 0); /* Generator */ rb_cGenerator = rb_define_class_under(rb_cEnumerator, "Generator", rb_cObject); rb_include_module(rb_cGenerator, rb_mEnumerable); rb_define_alloc_func(rb_cGenerator, generator_allocate); rb_define_method(rb_cGenerator, "initialize", generator_initialize, -1); rb_define_method(rb_cGenerator, "initialize_copy", generator_init_copy, 1); rb_define_method(rb_cGenerator, "each", generator_each, -1); /* Yielder */ rb_cYielder = rb_define_class_under(rb_cEnumerator, "Yielder", rb_cObject); rb_define_alloc_func(rb_cYielder, yielder_allocate); rb_define_method(rb_cYielder, "initialize", yielder_initialize, 0); rb_define_method(rb_cYielder, "yield", yielder_yield, -2); rb_define_method(rb_cYielder, "<<", yielder_yield_push, -2); rb_provide("enumerator.so"); /* for backward compatibility */ } #undef rb_intern void Init_Enumerator(void) { id_rewind = rb_intern("rewind"); id_each = rb_intern("each"); id_call = rb_intern("call"); id_size = rb_intern("size"); id_yield = rb_intern("yield"); id_new = rb_intern("new"); id_initialize = rb_intern("initialize"); id_next = rb_intern("next"); id_result = rb_intern("result"); id_lazy = rb_intern("lazy"); id_eqq = rb_intern("==="); id_receiver = rb_intern("receiver"); id_arguments = rb_intern("arguments"); id_memo = rb_intern("memo"); id_method = rb_intern("method"); id_force = rb_intern("force"); id_to_enum = rb_intern("to_enum"); sym_each = ID2SYM(id_each); sym_cycle = ID2SYM(rb_intern("cycle")); InitVM(Enumerator); }