overload int()

Message-ID: <20010124190657.A8512@math.ohio-state.edu>

p4raw-id: //depot/perl@8545

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/Math/BigFloat.pm b/lib/Math/BigFloat.pm
index 74a023e0d8..4c520fdd49 100644
--- a/lib/Math/BigFloat.pm
+++ b/lib/Math/BigFloat.pm
@@ -18,6 +18,7 @@ use overload
 			 scalar fdiv(${$_[0]},$_[1])},
 'neg'	=>	sub {new Math::BigFloat &fneg},
 'abs'	=>	sub {new Math::BigFloat &fabs},
+'int'	=>	sub {new Math::BigInt &f2int},
 
 qw(
 ""	stringify
@@ -58,6 +59,13 @@ sub stringify {
     return $n;
 }
 
+sub import {
+  shift;
+  return unless @_;
+  die "unknown import: @_" unless @_ == 1 and $_[0] eq ':constant';
+  overload::constant float => sub {Math::BigFloat->new(shift)};
+}
+
 $div_scale = 40;
 
 # Rounding modes one of 'even', 'odd', '+inf', '-inf', 'zero' or 'trunc'.
@@ -235,6 +243,26 @@ sub ffround { #(fnum_str, scale) return fnum_str
 	}
     }
 }
+
+# Calculate the integer part of $x
+sub f2int { #(fnum_str) return inum_str
+    local($x) = ${$_[$[]};
+    if ($x eq 'NaN') {
+	die "Attempt to take int(NaN)";
+    } else {
+	local($xm,$xe) = split('E',$x);
+	if ($xe >= 0) {
+	    $xm . '0' x $xe;
+	} else {
+	    $xe = length($xm)+$xe;
+	    if ($xe <= 1) {
+		'+0';
+	    } else {
+	        substr($xm,$[,$xe);
+	    }
+	}
+    }
+}
     
 # compare 2 values returns one of undef, <0, =0, >0
 #   returns undef if either or both input value are not numbers