зеркало из https://github.com/github/ruby.git
139 строки
3.0 KiB
C
139 строки
3.0 KiB
C
/**********************************************************************
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prec.c -
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$Author$
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created at: Tue Jan 26 02:40:41 2000
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Copyright (C) 1993-2007 Yukihiro Matsumoto
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**********************************************************************/
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#include "ruby/ruby.h"
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VALUE rb_mPrecision;
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static ID prc_pr, prc_if;
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/*
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* call-seq:
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* num.prec(klass) => a_class
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*
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* Converts _self_ into an instance of _klass_. By default,
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* +prec+ invokes
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*
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* klass.induced_from(num)
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*
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* and returns its value. So, if <code>klass.induced_from</code>
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* doesn't return an instance of _klass_, it will be necessary
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* to reimplement +prec+.
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*/
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static VALUE
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prec_prec(VALUE x, VALUE klass)
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{
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return rb_funcall(klass, prc_if, 1, x);
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}
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/*
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* call-seq:
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* num.prec_i => Integer
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*
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* Returns an +Integer+ converted from _num_. It is equivalent
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* to <code>prec(Integer)</code>.
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*/
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static VALUE
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prec_prec_i(VALUE x)
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{
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VALUE klass = rb_cInteger;
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return rb_funcall(x, prc_pr, 1, klass);
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}
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/*
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* call-seq:
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* num.prec_f => Float
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*
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* Returns a +Float+ converted from _num_. It is equivalent
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* to <code>prec(Float)</code>.
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*/
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static VALUE
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prec_prec_f(VALUE x)
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{
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VALUE klass = rb_cFloat;
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return rb_funcall(x, prc_pr, 1, klass);
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}
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/*
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* call-seq:
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* Mod.induced_from(number) => a_mod
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*
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* Creates an instance of mod from. This method is overridden
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* by concrete +Numeric+ classes, so that (for example)
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*
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* Fixnum.induced_from(9.9) #=> 9
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*
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* Note that a use of +prec+ in a redefinition may cause
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* an infinite loop.
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*/
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static VALUE
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prec_induced_from(VALUE module, VALUE x)
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{
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rb_raise(rb_eTypeError, "undefined conversion from %s into %s",
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rb_obj_classname(x), rb_class2name(module));
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return Qnil; /* not reached */
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}
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/*
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* call_seq:
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* included
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*
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* When the +Precision+ module is mixed-in to a class, this +included+
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* method is used to add our default +induced_from+ implementation
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* to the host class.
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*/
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static VALUE
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prec_included(VALUE module, VALUE include)
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{
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switch (TYPE(include)) {
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case T_CLASS:
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case T_MODULE:
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break;
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default:
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Check_Type(include, T_CLASS);
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break;
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}
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rb_define_singleton_method(include, "induced_from", prec_induced_from, 1);
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return module;
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}
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/*
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* Precision is a mixin for concrete numeric classes with
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* precision. Here, `precision' means the fineness of approximation
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* of a real number, so, this module should not be included into
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* anything which is not a subset of Real (so it should not be
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* included in classes such as +Complex+ or +Matrix+).
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*/
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void
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Init_Precision(void)
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{
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#undef rb_intern
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#define rb_intern(str) rb_intern_const(str)
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rb_mPrecision = rb_define_module("Precision");
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rb_define_singleton_method(rb_mPrecision, "included", prec_included, 1);
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rb_define_method(rb_mPrecision, "prec", prec_prec, 1);
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rb_define_method(rb_mPrecision, "prec_i", prec_prec_i, 0);
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rb_define_method(rb_mPrecision, "prec_f", prec_prec_f, 0);
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prc_pr = rb_intern("prec");
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prc_if = rb_intern("induced_from");
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}
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