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authornobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2016-04-18 03:55:33 (GMT)
committernobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2016-04-18 03:55:33 (GMT)
commit39f31b8c87dc28fd95f4e07194ecc2c491e05f6a (patch)
tree85f6ee800a80f8c10e8e60a46cd86e56b026df56 /numeric.c
parentadc7cb240abea320c991430e98b633ad4e327e08 (diff)
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.c65
1 files changed, 63 insertions, 2 deletions
diff --git a/numeric.c b/numeric.c
index dd5e154..19e2fca 100644
--- a/numeric.c
+++ b/numeric.c
@@ -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);