/************************************************ 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 "ruby/ruby.h" #include "debug.h" /* * Document-class: Enumerable::Enumerator * * A class which provides a method `each' to be used as an Enumerable * object. */ VALUE rb_cEnumerator; static VALUE sym_each; VALUE rb_eStopIteration; struct enumerator { VALUE obj; ID meth; VALUE args; rb_block_call_func *iter; VALUE fib; VALUE dst; VALUE no_next; }; 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); } static struct enumerator * enumerator_ptr(VALUE obj) { struct enumerator *ptr; Data_Get_Struct(obj, struct enumerator, ptr); if (RDATA(obj)->dmark != enumerator_mark) { rb_raise(rb_eTypeError, "wrong argument type %s (expected Enumerable::Enumerator)", rb_obj_classname(obj)); } if (!ptr) { rb_raise(rb_eArgError, "uninitialized enumerator"); } return ptr; } /* * call-seq: * obj.to_enum(method = :each, *args) * obj.enum_for(method = :each, *args) * * Returns Enumerable::Enumerator.new(self, method, *args). * * e.g.: * * str = "xyz" * * enum = str.enum_for(:each_byte) * a = enum.map {|b| '%02x' % b } #=> ["78", "79", "7a"] * * # protects an array from being modified * a = [1, 2, 3] * some_method(a.to_enum) * */ static VALUE obj_to_enum(int argc, VALUE *argv, VALUE obj) { VALUE meth = sym_each; if (argc > 0) { --argc; meth = *argv++; } return rb_enumeratorize(obj, meth, argc, argv); } static VALUE each_slice_i(VALUE val, VALUE *memo) { VALUE ary = memo[0]; VALUE v = Qnil; long size = (long)memo[1]; rb_ary_push(ary, val); if (RARRAY_LEN(ary) == size) { v = rb_yield(ary); memo[0] = rb_ary_new2(size); } return v; } /* * call-seq: * e.each_slice(n) {...} * * Iterates the given block for each slice of elements. * * e.g.: * (1..10).each_slice(3) {|a| p a} * # outputs below * [1, 2, 3] * [4, 5, 6] * [7, 8, 9] * [10] * */ static VALUE enum_each_slice(VALUE obj, VALUE n) { long size = NUM2LONG(n); VALUE args[2], ary; if (size <= 0) rb_raise(rb_eArgError, "invalid slice size"); RETURN_ENUMERATOR(obj, 1, &n); args[0] = rb_ary_new2(size); args[1] = (VALUE)size; rb_block_call(obj, SYM2ID(sym_each), 0, 0, each_slice_i, (VALUE)args); ary = args[0]; if (RARRAY_LEN(ary) > 0) rb_yield(ary); return Qnil; } static VALUE each_cons_i(VALUE val, VALUE *memo) { VALUE ary = memo[0]; VALUE v = Qnil; long size = (long)memo[1]; if (RARRAY_LEN(ary) == size) { rb_ary_shift(ary); } rb_ary_push(ary, val); if (RARRAY_LEN(ary) == size) { v = rb_yield(rb_ary_dup(ary)); } return v; } /* * call-seq: * each_cons(n) {...} * * Iterates the given block for each array of consecutive * elements. * * e.g.: * (1..10).each_cons(3) {|a| p a} * # outputs below * [1, 2, 3] * [2, 3, 4] * [3, 4, 5] * [4, 5, 6] * [5, 6, 7] * [6, 7, 8] * [7, 8, 9] * [8, 9, 10] * */ static VALUE enum_each_cons(VALUE obj, VALUE n) { long size = NUM2LONG(n); VALUE args[2]; if (size <= 0) rb_raise(rb_eArgError, "invalid size"); RETURN_ENUMERATOR(obj, 1, &n); args[0] = rb_ary_new2(size); args[1] = (VALUE)size; rb_block_call(obj, SYM2ID(sym_each), 0, 0, each_cons_i, (VALUE)args); return Qnil; } static VALUE enumerator_allocate(VALUE klass) { struct enumerator *ptr; return Data_Make_Struct(klass, struct enumerator, enumerator_mark, -1, ptr); } static VALUE enumerator_each_i(VALUE v, VALUE enum_obj, int argc, VALUE *argv) { return rb_yield_values2(argc, argv); } static VALUE enumerator_init(VALUE enum_obj, VALUE obj, VALUE meth, int argc, VALUE *argv) { struct enumerator *ptr = enumerator_ptr(enum_obj); ptr->obj = obj; ptr->meth = rb_to_id(meth); ptr->iter = enumerator_each_i; if (argc) ptr->args = rb_ary_new4(argc, argv); ptr->fib = 0; ptr->dst = Qnil; ptr->no_next = Qfalse; return enum_obj; } /* * call-seq: * Enumerable::Enumerator.new(obj, method = :each, *args) * * Creates a new Enumerable::Enumerator object, which is to be * used as an Enumerable object using the given object's given * method with the given arguments. * * e.g.: * str = "xyz" * * enum = Enumerable::Enumerator.new(str, :each_byte) * a = enum.map {|b| '%02x' % b } #=> ["78", "79", "7a"] * */ static VALUE enumerator_initialize(int argc, VALUE *argv, VALUE obj) { VALUE recv, meth = sym_each; if (argc == 0) rb_raise(rb_eArgError, "wrong number of argument (0 for 1)"); recv = *argv++; if (--argc) { meth = *argv++; --argc; } return enumerator_init(obj, recv, meth, argc, argv); } /* :nodoc: */ static VALUE enumerator_init_copy(VALUE obj, VALUE orig) { struct enumerator *ptr0, *ptr1; ptr0 = enumerator_ptr(orig); if (ptr0->fib) { /* Fibers cannot be copied */ rb_raise(rb_eTypeError, "can't copy execution context"); } ptr1 = enumerator_ptr(obj); ptr1->obj = ptr0->obj; ptr1->meth = ptr0->meth; ptr1->iter = ptr0->iter; ptr1->args = ptr0->args; ptr1->fib = 0; return obj; } VALUE rb_enumeratorize(VALUE obj, VALUE meth, int argc, VALUE *argv) { return enumerator_init(enumerator_allocate(rb_cEnumerator), obj, meth, argc, argv); } /* * call-seq: * enum.each {...} * * Iterates the given block using the object and the method specified * in the first place. * */ static VALUE enumerator_each(VALUE obj) { struct enumerator *e; int argc = 0; VALUE *argv = 0; if (!rb_block_given_p()) return obj; e = enumerator_ptr(obj); if (e->args) { argc = RARRAY_LEN(e->args); argv = RARRAY_PTR(e->args); } return rb_block_call(e->obj, e->meth, argc, argv, e->iter, (VALUE)e); } static VALUE enumerator_with_index_i(VALUE val, VALUE *memo) { val = rb_yield_values(2, val, INT2FIX(*memo)); ++*memo; return val; } /* * call-seq: * e.with_index {|(*args), idx| ... } * * Iterates the given block for each elements with an index, which * start from 0. * */ static VALUE enumerator_with_index(VALUE obj) { struct enumerator *e = enumerator_ptr(obj); VALUE memo = 0; int argc = 0; VALUE *argv = 0; RETURN_ENUMERATOR(obj, 0, 0); if (e->args) { argc = RARRAY_LEN(e->args); argv = RARRAY_PTR(e->args); } return rb_block_call(e->obj, e->meth, argc, argv, enumerator_with_index_i, (VALUE)&memo); } static VALUE next_ii(VALUE i, VALUE obj, int argc, VALUE *argv) { rb_fiber_yield(argc, argv); return Qnil; } static VALUE next_i(VALUE curr, VALUE obj) { struct enumerator *e = enumerator_ptr(obj); VALUE nil = Qnil; rb_block_call(obj, rb_intern("each"), 0, 0, next_ii, obj); e->no_next = Qtrue; 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); } /* * 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, internal * position is rewinded then StopIteration is raised. * * Note that enumeration sequence by next method does not affect other * non-external enumeration methods, unless underlying iteration * methods itself has side-effect, e.g. IO#each_line. * */ static VALUE enumerator_next(VALUE obj) { struct enumerator *e = enumerator_ptr(obj); VALUE curr, v; curr = rb_fiber_current(); if (!e->fib || !rb_fiber_alive_p(e->fib)) { next_init(obj, e); } v = rb_fiber_resume(e->fib, 1, &curr); if (e->no_next) { e->fib = 0; e->dst = Qnil; e->no_next = Qfalse; rb_raise(rb_eStopIteration, "iteration reached at end"); } return v; } /* * call-seq: * e.rewind => e * * Rewinds the enumeration sequence by the next method. */ static VALUE enumerator_rewind(VALUE obj) { struct enumerator *e = enumerator_ptr(obj); e->fib = 0; e->dst = Qnil; e->no_next = Qfalse; return obj; } void Init_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_define_method(rb_mEnumerable, "each_slice", enum_each_slice, 1); rb_define_method(rb_mEnumerable, "each_cons", enum_each_cons, 1); rb_cEnumerator = rb_define_class_under(rb_mEnumerable, "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, 0); rb_define_method(rb_cEnumerator, "with_index", enumerator_with_index, 0); rb_define_method(rb_cEnumerator, "next", enumerator_next, 0); rb_define_method(rb_cEnumerator, "rewind", enumerator_rewind, 0); rb_eStopIteration = rb_define_class("StopIteration", rb_eIndexError); sym_each = ID2SYM(rb_intern("each")); rb_provide("enumerator.so"); /* for backward compatibility */ }