The Trunk: Kernel-nice.842.mcz

Nicolas Cellier uploaded a new version of Kernel to project The Trunk:
http://source.squeak.org/trunk/Kernel-nice.842.mcz

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

Name: Kernel-nice.842
Author: nice
Time: 16 March 2014, 11:21:19.525 pm
UUID: c5833439-ae84-4711-a40a-b2db5d766cb3
Ancestors: Kernel-nice.841

Avoid using #reciprocalFloorLog:
#reciprocalFloorLog: does the same as #floorLog: just with more noise.
Once upon a time it was required, but it is not anymore and should be deprecated.

Note that floorLog: already cumulates 3 rounding errors via (self ln / base ln)

(-1 to: (Float fminDenormalized floorLog: 10) + 1 by: -1)
        count: [:i |
                | pow |
                pow := 10 raisedTo: i.
                (pow asFloat floorLog: 10) < i and: [pow asFloat >= pow]].
89

But reciprocalFloorLog: is even worse:

(-1 to: (Float fminDenormalized floorLog: 10) + 1 by: -1)
        count: [:i |
                | pow |
                pow := 10 raisedTo: i.
                (pow asFloat reciprocalFloorLog: 10) < i and: [pow asFloat >= pow]].
 149

=============== Diff against Kernel-nice.841 ===============

Item was changed:
  ----- Method: Float>>absPrintOn:base:digitCount: (in category 'printing') -----
  absPrintOn: aStream base: base digitCount: digitCount
  "Print me in the given base, using digitCount significant figures."
 
  | fuzz x exp q fBase scale logScale xi |
  self isInfinite ifTrue: [^ aStream nextPutAll: 'Inf'].
  fBase := base asFloat.
  "x is myself normalized to [1.0, fBase), exp is my exponent"
+ exp := self floorLog: fBase.
- exp :=
- self < 1.0
- ifTrue: [self reciprocalFloorLog: fBase]
- ifFalse: [self floorLog: fBase].
  scale := 1.0.
  logScale := 0.
  [(x := fBase raisedTo: (exp + logScale)) = 0]
  whileTrue:
  [scale := scale * fBase.
  logScale := logScale + 1].
  x := self * scale / x.
  fuzz := fBase raisedTo: 1 - digitCount.
  "round the last digit to be printed"
  x := 0.5 * fuzz + x.
  x >= fBase
  ifTrue:
  ["check if rounding has unnormalized x"
  x := x / fBase.
  exp := exp + 1].
  (exp < 6 and: [exp > -4])
  ifTrue:
  ["decimal notation"
  q := 0.
  exp < 0 ifTrue: [1 to: 1 - exp do: [:i | aStream nextPut: ('0.0000'
  at: i)]]]
  ifFalse:
  ["scientific notation"
  q := exp.
  exp := 0].
  [x >= fuzz]
  whileTrue:
  ["use fuzz to track significance"
  xi := x asInteger.
  aStream nextPut: (Character digitValue: xi).
  x := x - xi asFloat * fBase.
  fuzz := fuzz * fBase.
  exp := exp - 1.
  exp = -1 ifTrue: [aStream nextPut: $.]].
  [exp >= -1]
  whileTrue:
  [aStream nextPut: $0.
  exp := exp - 1.
  exp = -1 ifTrue: [aStream nextPut: $.]].
  q ~= 0
  ifTrue:
  [aStream nextPut: $e.
  q printOn: aStream]!