/************************************************ 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. */ static VALUE rb_cEnumerator; static VALUE sym_each, sym_each_with_index, sym_each_slice, sym_each_cons; static VALUE proc_call(VALUE proc, VALUE args) { if (TYPE(args) != T_ARRAY) { args = rb_ary_new3(1, args); } return rb_proc_call(proc, args); } struct enumerator { VALUE method; VALUE proc; VALUE args; VALUE (*iter)(VALUE, struct enumerator *); }; static void enumerator_mark(void *p) { struct enumerator *ptr = p; rb_gc_mark(ptr->method); rb_gc_mark(ptr->proc); rb_gc_mark(ptr->args); } 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; } static VALUE enumerator_iter_i(VALUE i, struct enumerator *e) { return rb_yield(proc_call(e->proc, i)); } /* * 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, rb_intern("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, rb_intern("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_init(VALUE enum_obj, VALUE obj, VALUE meth, int argc, VALUE *argv) { struct enumerator *ptr = enumerator_ptr(enum_obj); ptr->method = rb_obj_method(obj, meth); if (rb_block_given_p()) { ptr->proc = rb_block_proc(); ptr->iter = enumerator_iter_i; } else { ptr->iter = (VALUE (*)(VALUE, struct enumerator *))rb_yield; } 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. * * 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); } 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->method, rb_intern("call"), 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->method, rb_intern("call"), argc, argv, enumerator_with_index_i, (VALUE)&memo); } /* * call-seq: * e.to_splat => array * * Convert this enumerator object to an array to splat. */ static VALUE enumerator_to_splat(VALUE range) { return rb_convert_type(range, T_ARRAY, "Array", "to_a"); } 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, "each", enumerator_each, 0); rb_define_method(rb_cEnumerator, "with_index", enumerator_with_index, 0); rb_define_method(rb_cEnumerator, "to_splat", enumerator_to_splat, 0); sym_each = ID2SYM(rb_intern("each")); sym_each_with_index = ID2SYM(rb_intern("each_with_index")); sym_each_slice = ID2SYM(rb_intern("each_slice")); sym_each_cons = ID2SYM(rb_intern("each_cons")); rb_provide("enumerator.so"); /* for backward compatibility */ }