One last thing. If you do: sd := STON fromString: '1345.76s2'. sd2 := ScaledDecimal readFromString: '1345.76s2'.
you can note that sd = sd2 returns false, and that sd - sd2 returns 0.00s2. Both numbers are different in the order of precision, because the first has numerator 5918715072783319 and denominator 4398046511104 and the second has numerator 33644 and denominator 25. I still have to fix this. Hope not to bore you too much. Regards 2014-06-02 1:56 GMT+02:00 José Comesaña <jose.comes...@gmail.com>: > And this is an improved version. More changes to avoid parsing weird > things as 123.456s3e2 (it could be improved, for sure, but I don't have any > more time...) > > parseNumber > | negated number | > negated := readStream peekFor: $-. > number := self parseNumberInteger. > (readStream peekFor: $.) > ifTrue: [ number := number + self parseNumberFraction ]. > (readStream peekFor: $s) > ifTrue: [ | scale | > scale := self parseNumberInteger. > number := ScaledDecimal newFromNumber: number scale: scale ] > ifFalse: [ > (readStream peekFor: $/) > ifTrue: [ | denominator | > denominator := self parseNumberInteger. > number := Fraction numerator: number denominator: denominator ] > ifFalse: [ > ((readStream peekFor: $e) or: [ readStream peekFor: $E ]) > ifTrue: [ number := number * self parseNumberExponent ]. > ] > ]. > negated > ifTrue: [ number := number negated ]. > self consumeWhitespace. > ^ number > > > 2014-06-02 1:51 GMT+02:00 José Comesaña <jose.comes...@gmail.com>: > > Hi Sven. >> >> First of all, I know that in VisualWorks there exists a class called >> FixedPoint, that is (more or less) similar to ScaledDecimal (is what the >> class comment says). But, instead of 123.45s2, VWs writes 123.45s. >> NEVERTHELESS, it can read 123.45s2 with no pain. >> >> There exists a Fraction type also in VW, which, I believe, uses the same >> notation as in Pharo. >> >> I know that portability is an important issue, but, at least for me, >> portability from Pharo to Pharo is the most important. I depend on >> ScaledDecimal for an application (for storing money values -changing the >> storage mode is not an option now-) and need the possibility of converting >> it to string and reading it back. The string version is my database, that >> gets loaded into memory upon program start. >> >> You can see here the changes I have made to STONReader >>#parseNumber: >> >> parseNumber >> | negated number | >> negated := readStream peekFor: $-. >> number := self parseNumberInteger. >> (readStream peekFor: $.) >> ifTrue: [ number := number + self parseNumberFraction ]. >> " -------------- New from here -------------- " >> (readStream peekFor: $s) >> ifTrue: [ | scale | >> scale := self parseNumberInteger. >> number := ScaledDecimal newFromNumber: number scale: scale ]. >> (readStream peekFor: $/) >> ifTrue: [ | denominator | >> denominator := self parseNumberInteger. >> number := Fraction numerator: number denominator: denominator ]. >> " -------------- to here -------------- " >> ((readStream peekFor: $e) or: [ readStream peekFor: $E ]) >> ifTrue: [ number := number * self parseNumberExponent ]. >> negated >> ifTrue: [ number := number negated ]. >> self consumeWhitespace. >> ^ number >> >> I am a newbie about STON. I don't know if it is correct, but it works >> for me, at least for some tests I have made. I know it needs improvements, >> thinking about strange strings we could receive. But I trust the writer not >> to create such weird things. >> >> I could suggest another way of making the function of parseNumber (OK, >> OK, I know I am thinking from a Pharo-only perspective...). Seeing that >> number parsing always ends with this condition: >> >> readStream atEnd not and: [ readStream peek isDigit ] >> >> why not create a temporary string (including possibility of $e, $s, $/, >> even $@ ...) to that point (tmpString) and do: >> >> number := Number readFromString: tmpString >> >> That way, we would have a "native" parsing in each language >> >> Hope this helps. If someone needs more information, pleas ask. >> >> Best regards >> >> >> >> 2014-05-31 21:29 GMT+02:00 Sven Van Caekenberghe <s...@stfx.eu>: >> >> Hi José, >>> >>> On 31 May 2014, at 01:32, José Comesaña <jose.comes...@gmail.com> wrote: >>> >>> > Wouldn't it be good if STON could save ScaledDecimals as 12345.678s?. >>> That way, we could read them back again as ScaledDecimal, instead of Float. >>> I have tried and it seems quite useful. >>> > >>> > Regards >>> >>> That is an interesting idea and it is probably nice to have for those >>> relying on ScaledDecimals. >>> >>> One of the ideas of STON is to be portable across dialects, so I am >>> wondering if ScaledDecimals exists everywhere ? >>> >>> I am curious as to how you did it though, since STONReader basically >>> contains its own number parser. Could you share your code ? >>> >>> Sven >>> >> >> >
