The Trunk: Kernel-nice.921.mcz

Nicolas Cellier uploaded a new version of Kernel to project The Trunk:
http://source.squeak.org/trunk/Kernel-nice.921.mcz

==================== Summary ====================

Name: Kernel-nice.921
Author: nice
Time: 1 May 2015, 3:09:15.528 pm
UUID: 1ce76bf5-1e32-4d12-b7b1-9f23a75d37b2
Ancestors: Kernel-topa.920

Provide an exact version for #floorLog: for those Number using exact arithmetic
(as proposed in inbox Kernel-nice.721 / 11 December 2012).

Previous version was not exact, otherwise this count would have been zero:
    (-300 to: -1) count: [:n | n ~= ((10 raisedTo: n) floorLog: 10)].

Note that this won't make #log: exact, and could lead to disagreement between the two functions.
However, old behavior compatible with log: is still possible by passing the radix argument asFloat, so this is not a real problem.

=============== Diff against Kernel-topa.920 ===============

Item was added:
+ ----- Method: Fraction>>floorLog: (in category 'mathematical functions') -----
+ floorLog: radix
+ "Unlike super, this version is exact when radix is integer"
+
+ | d n |
+ radix isInteger ifFalse: [^super floorLog: 10].
+ n := numerator floorLog: radix.
+ d := denominator floorLog: radix.
+ ^(numerator * (radix raisedTo: d))
+ < (denominator * (radix raisedTo: n))
+ ifTrue: [n - d - 1]
+ ifFalse: [n - d]!

Item was added:
+ ----- Method: Integer>>floorLog: (in category 'mathematical functions') -----
+ floorLog: radix
+ "Unlike super, this version is exact when radix is integer"
+
+ radix isInteger ifFalse: [^super floorLog: 10].
+ self <= 0 ifTrue: [^DomainError signal: 'floorLog: is only defined for x > 0.0'].
+ ^(self numberOfDigitsInBase: radix) - 1!

Item was added:
+ ----- Method: ScaledDecimal>>floorLog: (in category 'mathematical functions') -----
+ floorLog: radix
+ "Unlike super, this version is exact when radix is integer"
+
+ ^self asFraction floorLog: radix!