/********************************************************************** prec.c - \$Author: matz \$ \$Date: 2006/04/09 16:10:36 \$ created at: Tue Jan 26 02:40:41 2000 Copyright (C) 1993-2003 Yukihiro Matsumoto **********************************************************************/ #include "ruby.h" VALUE rb_mPrecision; static ID prc_pr, prc_if; /* * call-seq: * num.prec(klass) => a_klass * * Converts _self_ into an instance of _klass_. By default, * +prec+ invokes * * klass.induced_from(num) * * and returns its value. So, if `klass.induced_from` * doesn't return an instance of _klass_, it will be necessary * to reimplement +prec+. */ static VALUE prec_prec(x, klass) VALUE x, klass; { return rb_funcall(klass, prc_if, 1, x); } /* * call-seq: * num.prec_i => Integer * * Returns an +Integer+ converted from _num_. It is equivalent * to `prec(Integer)`. */ static VALUE prec_prec_i(x) VALUE x; { VALUE klass = rb_cInteger; return rb_funcall(x, prc_pr, 1, klass); } /* * call-seq: * num.prec_f => Float * * Returns a +Float+ converted from _num_. It is equivalent * to `prec(Float)`. */ static VALUE prec_prec_f(x) VALUE x; { VALUE klass = rb_cFloat; return rb_funcall(x, prc_pr, 1, klass); } /* * call-seq: * Mod.induced_from(number) => a_mod * * Creates an instance of mod from. This method is overridden * by concrete +Numeric+ classes, so that (for example) * * Fixnum.induced_from(9.9) #=> 9 * * Note that a use of +prec+ in a redefinition may cause * an infinite loop. */ static VALUE prec_induced_from(module, x) VALUE module, x; { rb_raise(rb_eTypeError, "undefined conversion from %s into %s", rb_obj_classname(x), rb_class2name(module)); return Qnil; /* not reached */ } /* * call_seq: * included * * When the +Precision+ module is mixed-in to a class, this +included+ * method is used to add our default +induced_from+ implementation * to the host class. */ static VALUE prec_included(module, include) VALUE module, include; { switch (TYPE(include)) { case T_CLASS: case T_MODULE: break; default: Check_Type(include, T_CLASS); break; } rb_define_singleton_method(include, "induced_from", prec_induced_from, 1); return module; } /* * Precision is a mixin for concrete numeric classes with * precision. Here, `precision' means the fineness of approximation * of a real number, so, this module should not be included into * anything which is not a subset of Real (so it should not be * included in classes such as +Complex+ or +Matrix+). */ void Init_Precision() { rb_mPrecision = rb_define_module("Precision"); rb_define_singleton_method(rb_mPrecision, "included", prec_included, 1); rb_define_method(rb_mPrecision, "prec", prec_prec, 1); rb_define_method(rb_mPrecision, "prec_i", prec_prec_i, 0); rb_define_method(rb_mPrecision, "prec_f", prec_prec_f, 0); prc_pr = rb_intern("prec"); prc_if = rb_intern("induced_from"); }