Method: BigDecimal#-

Defined in:
bigdecimal.c

#-(value) ⇒ Object

Returns the BigDecimal difference of self and value:

b = BigDecimal('333333.333') # => 0.333333333e6
b - 2                        # => 0.333331333e6
b - 2.0                      # => 0.333331333e6
b - Rational(2, 1)           # => 0.333331333e6
b - Complex(2, 0)            # => (0.333331333e6+0i)

See the Note About Precision.



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# File 'bigdecimal.c', line 1502

static VALUE
BigDecimal_sub(VALUE self, VALUE r)
{
    ENTER(5);
    Real *c, *a, *b;
    size_t mx;

    GUARD_OBJ(a, GetVpValue(self,1));
    if (RB_TYPE_P(r, T_FLOAT)) {
	b = GetVpValueWithPrec(r, 0, 1);
    }
    else if (RB_TYPE_P(r, T_RATIONAL)) {
	b = GetVpValueWithPrec(r, a->Prec*VpBaseFig(), 1);
    }
    else {
	b = GetVpValue(r,0);
    }

    if (!b) return DoSomeOne(self,r,'-');
    SAVE(b);

    if (VpIsNaN(b)) return b->obj;
    if (VpIsNaN(a)) return a->obj;

    mx = GetAddSubPrec(a,b);
    if (mx == (size_t)-1L) {
        GUARD_OBJ(c, NewZeroWrapLimited(1, VpBaseFig() + 1));
        VpAddSub(c, a, b, -1);
    }
    else {
        GUARD_OBJ(c, NewZeroWrapLimited(1, mx *(VpBaseFig() + 1)));
        if (!mx) {
            VpSetInf(c,VpGetSign(a));
        }
        else {
            VpAddSub(c, a, b, -1);
        }
    }
    return VpCheckGetValue(c);
}