/************************************************ 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.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 proc; VALUE args; rb_block_call_func *iter; }; static void enumerator_mark _((void *)); static void enumerator_mark(p) void *p; { struct enumerator *ptr = p; rb_gc_mark(ptr->obj); rb_gc_mark(ptr->args); } static struct enumerator * enumerator_ptr(obj) 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 || ptr->obj == Qundef) { 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(argc, argv, obj) 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(val, memo) 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) {...} * e.each_slice(n) * * Iterates the given block for each slice of elements. If no * block is given, returns an enumerator. * * 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(obj, n) VALUE obj, 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(val, memo) 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) {...} * each_cons(n) * * Iterates the given block for each array of consecutive * elements. If no block is given, returns an enumerator.a * * 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(obj, n) VALUE obj, 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)); static VALUE enumerator_allocate(klass) VALUE klass; { struct enumerator *ptr; VALUE enum_obj; enum_obj = Data_Make_Struct(klass, struct enumerator, enumerator_mark, -1, ptr); ptr->obj = Qundef; return enum_obj; } static VALUE enumerator_each_i _((VALUE, VALUE)); static VALUE enumerator_each_i(v, enum_obj) VALUE v; VALUE enum_obj; { return rb_yield(v); } static VALUE enumerator_init(enum_obj, obj, meth, argc, argv) VALUE enum_obj; VALUE obj; VALUE meth; int argc; VALUE *argv; { struct enumerator *ptr; Data_Get_Struct(enum_obj, struct enumerator, ptr); if (!ptr) { rb_raise(rb_eArgError, "unallocated enumerator"); } ptr->obj = obj; ptr->meth = rb_to_id(meth); ptr->iter = enumerator_each_i; if (argc) ptr->args = rb_ary_new4(argc, argv); 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. * * Use of this method is discouraged. Use Kernel#enum_for() instead. */ static VALUE enumerator_initialize(argc, argv, obj) 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(obj, orig) VALUE obj; VALUE orig; { struct enumerator *ptr0, *ptr1; ptr0 = enumerator_ptr(orig); Data_Get_Struct(obj, struct enumerator, ptr1); if (!ptr1) { rb_raise(rb_eArgError, "unallocated enumerator"); } ptr1->obj = ptr0->obj; ptr1->meth = ptr0->meth; ptr1->iter = ptr0->iter; ptr1->args = ptr0->args; return obj; } VALUE rb_enumeratorize(obj, meth, argc, argv) 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. If no block is given, returns self. * */ static VALUE enumerator_each(obj) 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(val, memo) VALUE val; VALUE *memo; { val = rb_yield_values(2, val, INT2FIX(*memo)); ++*memo; return val; } /* * call-seq: * e.with_index {|(*args), idx| ... } * e.with_index * * Iterates the given block for each elements with an index, which * start from 0. If no block is given, returns an enumerator. * */ static VALUE enumerator_with_index(obj) 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); } /* * 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. * * Caution: Calling this method causes the "generator" library to be * loaded. */ static VALUE enumerator_next(obj) VALUE obj; { rb_require("generator"); return rb_funcall(obj, rb_intern("next"), 0, 0); } /* * call-seq: * e.rewind => e * * Rewinds the enumeration sequence by the next method. */ static VALUE enumerator_rewind(obj) VALUE obj; { rb_require("generator"); return rb_funcall(obj, rb_intern("rewind"), 0, 0); } void Init_Enumerator() { 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, "enum_slice", enum_each_slice, 1); rb_define_method(rb_mEnumerable, "each_cons", enum_each_cons, 1); rb_define_method(rb_mEnumerable, "enum_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, "each_with_index", enumerator_with_index, 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 */ }