diff options
author | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2016-04-18 03:55:33 +0000 |
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committer | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2016-04-18 03:55:33 +0000 |
commit | 47b092e42b3b544a62b7e53b8fae3e0d4f04438a (patch) | |
tree | 85f6ee800a80f8c10e8e60a46cd86e56b026df56 /numeric.c | |
parent | 321ff96f66b9b1a3780002b501c7f39fc784a851 (diff) | |
download | ruby-47b092e42b3b544a62b7e53b8fae3e0d4f04438a.tar.gz |
numeric.c: int_truncate
* numeric.c (int_truncate): add an optional parameter, digits, as
well as Integer#round. [Feature #12245]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54624 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'numeric.c')
-rw-r--r-- | numeric.c | 65 |
1 files changed, 63 insertions, 2 deletions
@@ -1935,6 +1935,36 @@ rb_int_ceil(VALUE num, int ndigits) return rb_int_plus(num, rb_int_minus(f, rb_int_modulo(num, f))); } +VALUE +rb_int_truncate(VALUE num, int ndigits) +{ + VALUE f; + VALUE m; + + if (int_round_zero_p(num, ndigits)) + return INT2FIX(0); + f = int_pow(10, -ndigits); + if (FIXNUM_P(num) && FIXNUM_P(f)) { + SIGNED_VALUE x = FIX2LONG(num), y = FIX2LONG(f); + int neg = x < 0; + if (neg) x = -x; + x = x / y * y; + if (neg) x = -x; + return LONG2NUM(x); + } + if (RB_TYPE_P(f, T_FLOAT)) { + /* then int_pow overflow */ + return INT2FIX(0); + } + m = rb_int_modulo(num, f); + if (int_neg_p(num)) { + return rb_int_plus(num, rb_int_minus(f, m)); + } + else { + return rb_int_minus(num, m); + } +} + /* * call-seq: * float.round([ndigits]) -> integer or float @@ -2817,7 +2847,7 @@ rb_num2ull(VALUE val) * * As +int+ is already an Integer, all these methods simply return the receiver. * - * Synonyms are #to_int, #truncate. + * Synonyms is #to_int */ static VALUE @@ -4347,6 +4377,37 @@ int_ceil(int argc, VALUE* argv, VALUE num) } /* + * call-seq: + * int.truncate([ndigits]) -> integer or float + * + * Returns the smallest number than or equal to +int+ in decimal + * digits (default 0 digits). + * + * Precision may be negative. Returns a floating point number when +ndigits+ + * is positive, +self+ for zero, and truncate up for negative. + * + * 1.truncate #=> 1 + * 1.truncate(2) #=> 1.0 + * 15.truncate(-1) #=> 10 + */ + +static VALUE +int_truncate(int argc, VALUE* argv, VALUE num) +{ + int ndigits; + + if (!rb_check_arity(argc, 0, 1)) return num; + ndigits = NUM2INT(argv[0]); + if (ndigits > 0) { + return rb_Float(num); + } + if (ndigits == 0) { + return num; + } + return rb_int_truncate(num, ndigits); +} + +/* * Document-class: ZeroDivisionError * * Raised when attempting to divide an integer by 0. @@ -4518,7 +4579,7 @@ Init_Numeric(void) rb_define_method(rb_cInteger, "to_f", int_to_f, 0); rb_define_method(rb_cInteger, "floor", int_floor, -1); rb_define_method(rb_cInteger, "ceil", int_ceil, -1); - rb_define_method(rb_cInteger, "truncate", int_to_i, 0); + rb_define_method(rb_cInteger, "truncate", int_truncate, -1); rb_define_method(rb_cInteger, "round", int_round, -1); rb_define_method(rb_cInteger, "<=>", int_cmp, 1); |